science-and-technology---content-summary

Editor's Note: Mark Rodeghier is director of the J. Allen Hynek Center for UFO Studies. This article is from The International UFO Reporter, Spring 1998, vol 23, number 1.

Goverment UFO Documents on the Internet

By Mark Rodeghier

In the middle to late 1970s, several individuals, mostly associated with the group Citizens Against UFO Secrecy (CAUS), used the Freedom of Information Act (FOIA) to compel various U.S. government agencies to release their files on the UFO phenomenon. The FBI, the National Security Agency (NSA), and the CIA eventually complied with the law and released documents relating to UFOs, although the NSA did so only after a lawsuit was filed by CAUS. In addition, with the help of FOIA, the air force was forced to make available UFO documents which it had collected or produced after Project Blue Book closed in late 1969.

These documents do not contain a smoking gun to prove that the U.S. government has a secret UFO project. They did show that many agencies had an ongoing interest in the UFO phenomenon that was often independent of the air force’s UFO project, and that the interest continued after it ended.

Many of these documents have been made available to the public by UFO groups, including CUFOS and the Fund for UFO Research. It was also possible to obtain these documents directly from the agencies involved, which undoubtedly has increased their workload on a subject they consider to be unimportant.

The growth of the Internet has now provided at least two agencies--the FBI and the NSA--with a resource which they can use to reduce their workload. In the past few months, both agencies have placed all their released UFO documents on their Web sites. I assume that, in the future, people who contact the FBI and NSA for copies of UFO documents will first be referred to the Web sites, thus placing the burden of retrieval on the public.

Nevertheless, this arrangement is an excellent opportunity for all those who wish to directly read FBI and NSA UFO documents, at only the cost of a phone call to your Internet provider. The address (or URL) of each site is listed at the end of this article.

FBI Documents

The FBI’s involvement with UFO investigation was bief. After Kenneth Arnold’s sighting and the public furor it caused, the FBI became quite active in UFO investigation in a parallel effort to that of the air force. The FBI worked in an unsystematic fashion for a couple of months, mainly interviewing witnesses to sightings.

Then in September 1947, the FBI learned from a source in the air force that the military wanted the FBI to investigate cases of disks found on the ground, which were essentially hoaxes (or so the FBI thought). This didn’t sit well with J. Edgar Hoover, FBI director, who didn’t want his men wasting time looking into obvious hoaxes while the air force investigated reports of UFOs in the air. Consequently, Hoover wrote to Major General George C. McDonald on September 27, 1947, and told him that the FBI was immediately discontinuing its investigative activity. This letter is shown in Figure 1.

|Fig. 1. J. Edgar Hoover letter to Air Force that ended FBI UFO investigations, Sept. 27. 1947._

Since then the FBI has done little to investigate UFO reports, although it did allegedly investigate some UFO witnesses and investigators, especially during the 1950s, when concern about the Soviets and subversion was widespread.

The section of the FBI Web site with the UFO documents is entitled "Unusual Phenomena" because it also contains documents concerning the FBI investigation of animal mutilations in the southwest. The investigation was begun because of several mutilations in New Mexico and political pressure at the federal level to find the culprits. The FBI eventually concluded that the mutilations were the work of predators, a judgment that was hotly disputed by some ranchers and local law enforcement officials.

NSA Documents

The number of UFO documents from the NSA is more extensive. This is not because the NSA conducted UFO investigations, but instead because the nature of the NSA’s work is to monitor communications around the globe that might affect U.S. security. At times, these communications concern the sighting of unusual objects or phenomena, which the NSA collects as part of its routine duties.

Although the agency was forced to release most of its UFO-related documents (some are still withheld for national security reasons), many of them are covered with deletions. I’ve chosen one at random from communications intelligence reports to provide an example (see Figure 2). All identifying details as to time, place, witnesses, and report source have been removed, leaving too few details to make research feasible.

|Fig. 2 NSA sanitized communication concerning a possible UFO sighting.__________________

The list of NSA documents includes, amazingly enough, some articles from UFO journals, such as The U.S. Government and the Iran Case from IUR. Many airgrams from the Department of State reporting on UFO sightings overseas are listed; these documents were essentially internal telegrams used to communicate quickly between agencies. There are also some Roswell documents from the Air Force’s latest investigations.

The NSA Web site includes a speculative article, written in 1968, entitled UFO Hypothesis and Survival Questions. This document, which was originally classified secret, discusses various hypotheses for the UFO phenomenon, including hoaxes, natural phenomena, secret government devices, and extraterrestrials, and considers the implications for security if each is true. It concludes by noting that a study of UFOs may provide an pportunity for man to "recognize and adapt to real environmental situations." A portion of the first page of this seven-page document is shown in Figure 3.

|Fig. 3. NSA draft report on UFOs and the man's survival.______________________________

There is no evidence that this draft report was ever completed, or that it began as part of an official NSA UFO investigation, but it does make for interesting reading. It also shows how seriously the UFO question was viewed by some in the intelligence community in the late 1960s.

The files on both Web sites are in PDF, or portable document format. You must download (for free) the Adobe Acrobat Reader program to view them. The files can be viewed online or downloaded for later viewing. However, you should be forewarned that many of the files are quite large, as much as seven megabytes in size, so you’ll need a relatively fast Internet connection to make the wait less than interminable.

The location of the FBI files is http://www.fbi.gov/foipa/ufo.htm [link is dead] .The location of the NSA files is http://www.nsa.gov:8080/docs/efoia/released/ufo.html [link is dead] Also check out the Black Vault at http://www.blackvault.com

The CIA has finally made its UFO documents available to the public. They may be viewed at http://www.foia.ucia.gov/scripts/popdoc.asp?docType=ufo [link is dead]

v For more details visit:

Ø http://www.cufos.org/UFO_Documents_internet.html

UFOs report

Thu, 05 Nov 2009 14:10:31 +0100

Unidentified flying object

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"UFO" redirects here. For other uses, see UFO (disambiguation).

Unidentified flying object (commonly abbreviated as UFO or U.F.O.) is the popular term for any aerial phenomenon whose cause cannot be easily or immediately identified. The United States Air Force, which coined the term in 1952, initially defined UFOs as those objects that remain unidentified after scrutiny by expert investigators,^[1] though the term UFO is often used more generally to describe any sighting unidentifiable to the reporting observer(s). Popular culture frequently takes the term UFO as a synonym for alien spacecraft. Cults have become associated with UFOs, and mythology and folklore have evolved around the phenomenon.^[2] Some investigators now prefer to use the broader term unidentified aerial phenomenon (or UAP), to avoid the confusion and speculative associations that have become attached to UFO.^[3] Another widely known acronym for UFO in Spanish, French, Portuguese and Italian is OVNI.

Studies have established that the majority of UFOs are observations of some real but conventional object—most commonly aircraft, balloons, or astronomical objects such as meteors or bright planets—that have been misidentified by the observer as anomalies while a small percentage of reported UFOs are hoaxes.^[4] Only a small percentage of reported sightings (usually 5 to 20%) can be classified as unidentified flying objects in the strictest sense (see below for some studies).

Some scientists have argued that all UFO sightings are misidentifications of natural phenomena^[5] and historically, there was debate among some scientists about whether scientific investigation was warranted given available empirical data.^[6]^[7]^[8]^[9]^[10] Very little peer-reviewed literature has been published in which scientists have proposed, studied or supported non-prosaic explanations for UFOs. Allen Hynek was a trained astronomer who participated in Project Bluebook after doing research as a federal government employee. He formed the opinion that some UFO reports could not be scientifically explained. Through his founding of the Center for UFO Studies and participation at CUFOs he spent the rest of his life researching and documenting UFOs. The movie Close Encounters of the Third Kind had a character loosely based on Hynek. Another group studying UFOs is Mutual UFO Network. MUFON is a grass roots based organization known for publishing one of the first UFO investigators handbooks. This handbook went into great detail on how to document alleged UFO sightings.

UFO reports became frequent after the first widely publicized U.S. sighting, reported by private pilot Kenneth Arnold in 1947, that gave rise to the popular terms "flying saucer" and "flying disc." Since then, millions of people have reported that they have seen UFOs.^[11]

Contents

[hide]

1 History

1.1 The Kenneth Arnold sightings

2 Investigations

2.1 American investigations

3 Famous American Cases

3.1 Canadian investigation

4 Famous Canadian Cases

5 Famous British Cases

6 Identification of UFOs

6.1 UFO hypotheses

7 Physical evidence

7.1 Reverse engineering

8 Ufology

9 Conspiracy theories

9.1 Allegations of evidence suppression

11.1 Use in film and television

14 External links

[edit] History

Unexplained aerial observations have been reported throughout history. Some were undoubtedly astronomical in nature: comets, bright meteors, one or more of the five planets that can be seen with the naked eye, planetary conjunctions, or atmospheric optical phenomena such as parhelia and lenticular clouds. An example is Halley's Comet, which was recorded first by Chinese astronomers in 240 B.C. and possibly as early as 467 B.C.

Other historical reports seem to defy prosaic explanation, but assessing such accounts is difficult. Whatever their actual cause, such sightings throughout history were often treated as supernatural portents, angels, or other religious omens. Some objects in medieval paintings can seem strikingly similar to UFO reports.^[12] Art historians explain those objects as religious symbols, often represented in many other paintings of Middle-Age and Renaissance.^[13]

Shen Kuo (1031–1095), a Song Chinese government scholar-official and prolific polymath inventor and scholar, wrote a vivid passage in his Dream Pool Essays (1088) about an unidentified flying object. He recorded the testimony of eyewitnesses in 11th-century Anhui and Jiangsu (especially in the city of Yangzhou), who stated that a flying object with opening doors would shine a blinding light from its interior (from an object shaped like a pearl) that would cast shadows from trees for ten miles in radius, and was able to take off at tremendous speeds.^[14]

On January 25, 1878, The Denison Daily News wrote that local farmer John Martin had reported seeing a large, dark, circular flying object resembling a balloon flying "at wonderful speed." Martin also said it appeared to be about the size of a saucer, the first known use of the word "saucer" in association with a UFO.^[15]
On February 28, 1904, there was a sighting by three crew members on the USS Supply 300 miles west of San Francisco, reported by Lt. Frank Schofield, later to become Commander-in-Chief of the Pacific Battle Fleet. Schofield wrote of three bright red egg-shaped and circular objects flying in echelon formation that approached beneath the cloud layer, then changed course and "soared" above the clouds, departing directly away from the earth after two to three minutes. The largest had an apparent size of about six suns.^[16]
1916 and 1926: The three oldest known pilot UFO sightings, of 1305 cataloged by NARCAP. On January 31, 1916, a UK pilot near Rochford reported a row of lights, like lighted windows on a railway carriage, that rose and disappeared. In January 1926, a pilot reported six "flying manhole covers" between Wichita, Kansas and Colorado Springs, Colorado. In late September 1926, an airmail pilot over Nevada was forced to land by a huge, wingless cylindrical object.^[17]
On August 5, 1926, while traveling in the Humboldt Mountains of Tibet's Kokonor region, Nicholas Roerich reported that members of his expedition saw "something big and shiny reflecting the sun, like a huge oval moving at great speed. Crossing our camp the thing changed in its direction from south to southwest. And we saw how it disappeared in the intense blue sky. We even had time to take our field glasses and saw quite distinctly an oval form with shiny surface, one side of which was brilliant from the sun.” ^[18] Another description by Roerich was, "...A shiny body flying from north to south. Field glasses are at hand. It is a huge body. One side glows in the sun. It is oval in shape. Then it somehow turns in another direction and disappears in the southwest." ^[19]
In the Pacific and European theatres during World War II, "Foo-fighters" (metallic spheres, balls of light and other shapes that followed aircraft) were reported and on occasion photographed by Allied and Axis pilots. Some proposed Allied explanations at the time included St. Elmo's Fire, the planet Venus, hallucinations from oxygen deprivation, or German secret weapon.^[20]^[21]
On February 25, 1942, U.S. Army observers reported unidentified aircraft both visually and on radar over the Los Angeles, California region. Antiaircraft artillery was fired at what was presumed to be Japanese planes. No readily apparent explanation was offered, though some officials dismissed the reports of aircraft as being triggered by anxieties over expected Japanese air attacks on California. However, Army Chief of Staff Gen. George C. Marshall and Secretary of War Henry Stimson insisted real aircraft were involved. The incident later became known as the Battle of Los Angeles, or the West coast air raid.
In 1946, there were over 2000 reports, collected primarily by the Swedish military, of unidentified aerial objects in the Scandinavian nations, along with isolated reports from France, Portugal, Italy and Greece, then referred to as "Russian hail", and later as "ghost rockets", because it was thought that these mysterious objects were possibly Russian tests of captured German V1 or V2 rockets. Although most were thought to be natural phenomena like meteors, over 200 were tracked on radar and deemed to be "real physical objects" by the Swedish military. In a 1948 top secret document, the Swedish military told the USAF Europe in 1948 that some of their investigators believed them to be extraterrestrial in origin. (See Wiki ghost rockets article for details)

[edit] The Kenneth Arnold sightings

Main article: Kenneth Arnold#June 24, 1947 UFO sighting

This shows the report Kenneth Arnold filed in 1947 about his UFO sighting.

The post World War II UFO phase in the United States began with a famous sighting by American businessman Kenneth Arnold on June 24, 1947 while flying his private plane near Mount Rainier, Washington. He reported seeing nine brilliantly bright objects flying across the face of Rainier.

This shows Kenneth Arnold holding a picture of a drawing of the crescent shaped UFO he saw in 1947.

Although there were other 1947 U.S. sightings of similar objects that preceded this, it was Arnold's sighting that first received significant media attention and captured the public's imagination. Arnold described what he saw as being "flat like a pie pan", "shaped like saucers and were so thin I could barely see them… ", "half-moon shaped, oval in front and convex in the rear. … they looked like a big flat disk" (see Arnold's drawing at right), and flew "like a saucer would if you skipped it across the water". (One of the objects, however, he would describe later as crescent-shaped, as shown in illustration at left.) Arnold’s descriptions were widely reported and within a few days gave rise to the terms flying saucer and flying disk.^[22] Arnold’s sighting was followed in the next few weeks by hundreds of other reported sightings, mostly in the U.S., but in other countries as well.

After reports of the Arnold sighting hit the media, other cases began to be reported in increasing numbers. In one instance a United Airlines crew sighting of nine more disc-like objects over Idaho on the evening of July 4. At the time, this sighting was even more widely reported than Arnold’s and lent considerable credence to Arnold’s report.^[23]

American UFO researcher Ted Bloecher, in his comprehensive review of newspaper reports (including cases that preceded Arnold's), found a sudden surge upwards in sightings on July 4, peaking on July 6–8. Bloecher noted that for the next few days most American newspapers were filled with front-page stories of the new "flying saucers" or "flying discs". Reports began to rapidly tail off after July 8,^[24] when officials began issuing press statements on the Roswell UFO incident, in which they explained debris found on the ground by a rancher as being that of a weather balloon.^[25]

Over several years in the 1960s, Bloecher (aided by physicist James E. McDonald) discovered 853 flying disc sightings that year from 140 newspapers from Canada, Washington D.C, and every U.S. state except Montana.^[26]

[edit] Investigations

UFOs have been subject to investigations over the years that vary widely in scope and scientific rigor. Governments or independent academics in the United States, Canada, the United Kingdom, Japan, Peru, France, Belgium, Sweden, Brazil, Chile, Uruguay, Mexico, Spain, and the Soviet Union are known to have investigated UFO reports at various times.

Among the best known government studies are the ghost rockets investigation by the Swedish military (1946–1947), Project Blue Book, previously Project Sign and Project GrudgeExtraterrestrial life

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For fiction, see Extraterrestrials in fiction.

A 1967 Soviet Union 16 kopeks postage stamp, with a satellite from an imagined extraterrestrial civilization.

For other uses, see Alien (disambiguation).

Extraterrestrial life is defined as life which does not originate from planet Earth. The existence of life outside the planet is theoretical and all assertions of such life remain disputed.

Hypotheses regarding the origin(s) of extraterrestrial life, if it exists, are as follows: one proposes that it may have emerged, independently, from different places in the universe. An alternative hypothesis is panspermia or exogenesis, which holds that life emerges from one location, then spreads between habitable planets. These two hypotheses are not mutually exclusive. The study and theorization of extraterrestrial life is known as astrobiology, exobiology or xenobiology. Speculated forms of extraterrestrial life range from life with the simplicity of bacteria to sapient or sentient beings.

Suggested locations which might have once developed, or presently continue to host life similar to our own, include the planets Venus ^[1] and Mars, moons of Jupiter and Saturn (e.g. Europa,^[2] Enceladus and Titan) and Gliese 581 c and d, recently discovered to be near Earth-mass extrasolar planets apparently located in their star's habitable zone, and with the potential to have liquid water.^[3]

To date, no credible evidence of extraterrestrial life has been discovered which has been generally accepted by the mainstream scientific community. All other proposals, including beliefs that some UFOs are of extraterrestrial origin (see extraterrestrial hypothesis) and claims of alien abduction, are considered hypothetical by most scientists. In 2006, New Scientist published a list of ten controversial pieces of evidence that extraterrestrial life exists,^[4] but scientists do not consider them credible since no direct observational evidence has been encountered.

Contents

[hide]

1 Possible basis of extraterrestrial life

2 Beliefs in extraterrestrial life

3 Scientific search for extraterrestrial life

[edit] Possible basis of extraterrestrial life

Several theories have been proposed about the possible basis of alien life from a biochemical, evolutionary or morphological viewpoint.

Alien life, such as bacteria, has been theorised by scientists such as Carl Sagan to exist in our solar system and quite possibly throughout the universe. However, no samples have been found by astronauts.
As of yet, no intelligent life has been discovered. However, many scientists, such as Carl Sagan, believe that it is nearly impossible that no other intelligent life exists in the universe.
UFO sightings are sightings of unidentified flying objects that may or may not be connected with extraterrestrial intelligent life. Many of these sightings can be dismissed as hoaxes or sightings of Earth based aircraft. However some sightings have gone unexplained, having been reported in some cases by police and airline pilots.

[edit] Biochemistry

Main articles: Biochemistry, Hypothetical types of biochemistry, and Water and life

All life on Earth requires carbon, hydrogen, oxygen, nitrogen, sulfur and phosphorus as well as numerous other elements in smaller amounts, notably minerals; it also requires water as the solvent in which biochemical reactions take place. Sufficient quantities of carbon and the other major life-forming elements, along with water, may enable the formation of living organisms on other planets with a chemical make-up and average temperature similar to that of Earth. Because Earth and other planets are made up of "star dust", i.e. relatively abundant chemical elements formed from stars which have ended their lives as supernovae, it is very probable that other planets may have been formed by elements of a similar composition to the Earth's. The combination of carbon and water in the chemical form of carbohydrates (e.g. sugar) can be a source of chemical energy on which life depends, and can also provide structural elements for life (such as ribose, in the molecules DNA and RNA, and cellulose in plants). Plants derive energy through the conversion of light energy into chemical energy via photosynthesis. Life, as currently recognized, requires carbon in both reduced (methane derivatives) and partially-oxidized (carbon oxides) states. It also appears to require nitrogen as a reduced ammonia derivative in all proteins, sulfur as a derivative of hydrogen sulfide in some necessary proteins, and phosphorus oxidized to phosphates in genetic material and in energy transfer. Adequate water as a solvent supplies adequate oxygen as constituents of biochemical substances.

Pure water is useful because it has a neutral pH due to its continued dissociation between hydroxide and hydronium ions. As a result, it can dissolve both positive metallic ions and negative non-metallic ions with equal ability. Furthermore, the fact that organic molecules can be either hydrophobic (repelled by water) or hydrophilic (soluble in water) creates the ability of organic compounds to orient themselves to form water-enclosing membranes. The fact that solid water (ice) is less dense than liquid water also means that ice floats, thereby preventing Earth's oceans from slowly freezing. Without this quality, the oceans could have frozen solid during the Snowball Earth episodes. Additionally, the Van der Waals forces between water molecules give it an ability to store energy with evaporation, which upon condensation is released. This helps to moderate the climate, cooling the tropics and warming the poles, helping to maintain the thermodynamic stability needed for life.

Carbon is fundamental to terrestrial life for its immense flexibility in creating covalent chemical bonds with a variety of non-metallic elements, principally nitrogen, oxygen and hydrogen. Carbon dioxide and water together enable the storage of solar energy in sugars, such as glucose. The oxidation of glucose releases biochemical energy needed to fuel all other biochemical reactions.

The ability to form organic acids (–COOH) and amine bases (–NH₂) gives rise to the possibility of neutralization dehydrating reactions to build long polymer peptides and catalytic proteins from monomer amino acids, and with phosphates to build not only DNA (the information-storing molecule of inheritance), but also ATP (the principal energy "currency" of cellular life).

Due to their relative abundance and usefulness in sustaining life, many have hypothesized that lifeforms elsewhere in the universe would also utilize these basic materials. However, other elements and solvents could also provide a basis for life. Silicon is most often deemed to be the probable alternative to carbon. Silicon lifeforms are proposed to have a crystalline morphology, and are theorized to be able to exist in high temperatures, such as on planets which are very close to their star. Life forms based in ammonia (rather than water) have also been suggested, though this solution appears less optimal than water.^[5]

When looked at from a chemical perspective, life is fundamentally a self-replicating reaction, but one which could arise under a great many conditions and with various possible ingredients, though carbon-oxygen within the liquid temperature range of water seems most conducive. Suggestions have even been made that self-replicating reactions of some sort could occur within the plasma of a star, though it would be highly unconventional.^[6]

Several pre-conceived ideas about the characteristics of life outside of Earth have been questioned. For example, NASA scientists believe that the color of photosynthesizing pigments on extrasolar planets might not be green.^[7]

[edit] Evolution and morphology

In addition to the biochemical basis of extraterrestrial life, many have also considered evolution and morphology. Science fiction has often depicted extraterrestrial life with humanoid and/or reptilian forms. Aliens have often been depicted as having light green or grey skin, with a large head, as well as four limbs — i.e. fundamentally humanoid. Other subjects, such as felines and insects, have also occurred in fictional representations of aliens.

A division has been suggested between universal and parochial (narrowly restricted) characteristics. Universals are features which are thought to have evolved independently more than once on Earth (and thus, presumably, are not too difficult to develop) and are so intrinsically useful that species will inevitably tend towards them. These include flight, sight, photosynthesis and limbs, all of which are thought to have evolved several times here on Earth. There is a huge variety of eyes, for example, and many of these have radically different working schematics and different visual foci: the visual spectrum, infrared, polarity and echolocation. Parochials, however, are essentially arbitrary evolutionary forms. These often have little inherent utility (or at least have a function which can be equally served by dissimilar morphology) and probably will not be replicated. Intelligent aliens could communicate through gestures, as deaf humans do, or by sounds created from structures unrelated to breathing, which happens on Earth when, for instance, cicadas vibrate their wings, or crickets rub their legs.

Attempting to define parochial features challenges many taken-for-granted notions about morphological necessity. Skeletons, which are essential to large terrestrial organisms according to the experts of the field of Gravitational biology, are almost assured to be replicated elsewhere in one form or another. Many also conjecture as to some type of egg-laying amongst extraterrestrial creatures, but mammalian mammary glands might be a singular case.

The assumption of radical diversity amongst putative extraterrestrials is by no means settled. While many exobiologists do stress that the enormously heterogeneous nature of life on Earth foregrounds an even greater variety in space, others point out that convergent evolution may dictate substantial similarities between Earth and extraterrestrial life. These two schools of thought are called "divergionism" and "convergionism" respectively.^[6]

[edit] Beliefs in extraterrestrial life

[edit] Ancient and early modern ideas

See also: Cosmic pluralism and Ancient astronauts

Beliefs in extraterrestrial life may have been present in ancient Babylon, Assyria, Sumer, Egypt, Arabia, China, India, and South America, although in these societies, cosmology was often associated with the supernatural, and the notion of alien life is difficult to distinguish from that of gods, demons, and such. The first important Western thinkers to argue systematically for a universe full of other planets and, therefore, possible extraterrestrial life were the ancient Greek writer Thales and his student Anaximander in the 7th and 6th centuries B.C. The atomists of Greece took up the idea, arguing that an infinite universe ought to have an

The mission of the SETI institute

Thu, 05 Nov 2009 13:58:46 +0100

TeamSETI

Join TeamSETI today to order an autographed copy of Space Exploration for Dummies, by SETI Institute scientist Cynthia Phillips, PhD. Membership benefits include: Our science magazine, Explorer, Advanced notice for special member events, access to exclusive web features such as our online member's only forums, membership card, discounts on merchandise and more... Join TeamSETI TODAY and get in on the search!

http://www.seti.org/Page.aspx?pid=1366

SETI at 50: 10 key moments in the search for extraterrestrial life

The Search for Extraterrestrial Intelligence, or SETI, is 50 years old this month. We look at 10 memorable events in the search for life on other planets.

By Tom Chivers
Published: 7:30AM BST 29 Sep 2009

Comments 2 | Comment on this article

In 2015, Voyager 1 will become the first man-made object to leave the solar system Photo: NASA

SETI was founded in response to a September 1959 Nature journal article, “Searching for Interstellar Communication”, which suggested that a systematic search for alien life was worthwhile.

Since then, it has spent 50 years listening to the stars with radio telescopes, and at times trying to send messages of its own to other planets.

· Found: hell planet where rock falls as rain

· Beatles space broadcast 'risks alien attack'

· Mars ancient water discovery

· Google shows history of Mars

Here are 10 of the most significant events in mankind’s search for other life.

Little Green Men: Pulsars
In 1967, astronomers in the UK spotted a radio signal from another star. Nothing too remarkable in that, as all stars emit radio waves.

What was unexpected, though, was that this one turned itself on and off with perfect regularity: one 0.04 second pulse every 1.3373 seconds.

The metronomic beat sparked speculation that it might be a signal from an alien life form, and the signal was given the name LGM-1, standing for Little Green Men.

In fact, the astronomers had discovered a new type of star – a pulsar. A form of neutron star (an incredibly dense dead star: one just 12 miles across would weigh more than our Sun), they rotate at a huge velocity, giving off powerful beams of radiation as they spin.

Martian bacteria?
In 1984, a rock was found in the Allan Hills, Antarctica. It is believed to have been formed on Mars around 4.5 billion years ago, before being blasted into space by meteorite impacts around 15 million years ago.

It then wandered through space for millions of years, before crashing into our planet about 11,000 years before the birth of Christ.

An interesting enough history, but the meteorite – known as ALH84001 – really made the headlines in 1996. Structures that resembled tiny fossilised bacteria were found, as were organic molecules, sparking theories of ancient life on Mars. The excitement grew so great that US President Bill Clinton made a televised announcement about the find.

Arguments over whether these really are evidence of Martian life, or whether the sample has become contaminated during its time on Earth, are still raging today.

Earth-like planets
‘Terrestrial’, or rocky, planets, are considered the most likely place for life to be found. There are four in our own solar system – Mercury, Venus, Earth and Mars.

But in the last few years, the first possible examples of Earth-like planets outside our system have been found. In 2007 European scientists said they had found two – the third and fourth planets around the red dwarf Gliese 581 – which might be habitable.

Water on Mars
This month the news broke that the Mars Reconnaissance Orbiter has spotted evidence of ice in five locations on Mars. It is the latest in a series of discoveries of water on the planet, indicating that the planet may have had a more humid climate at some stage in the last few thousand years.

Water is required for all known forms of life, so the existence of water on other planets increases the likelihood that life exists elsewhere.

Drake equation
The first serious attempt to quantify the likelihood of humanity coming into contact with alien life, the Drake equation reads: N=f^p n^e f^l fⁱ f^c L.

It states that if we know the rate of star formation, the percentage of stars that have habitable planets, and the percentage of those planets that are likely at any given time to support life that signals its existence to the universe, we could estimate how many civilisations in our galaxy we might communicate with.

Unfortunately, none of those factors are known, so we are still guessing.

The Aricebo Message
Not part of the search for life per se, but rather helping anyone else who may be looking for us. In November 1974, a message was beamed from the Aricebo radio telescope towards the M13 star cluster, about 25,000 light years away. The message, created by Drake equation author Frank Drake and physicist Carl Sagan, included an image of a human and information about the makeup of DNA.

Sadly, M13 will have moved by the time it arrives.

A later broadcast - beaming the music of the Beatles at the Pole Star, 431 light years away - was, in all apparent seriousness, condemned as inviting an interstellar attack from warlike aliens.

Voyager
Three years later, in 1977, the two Voyager space probes were launched. As well as their scientific equipment, they contain gold discs containing information about Earth, including Mozart’s music and greetings in 54 human languages. It is currently around 10 billion miles from Earth; its radio signals take 15 hours to reach us, even at the speed of light.

In May 2005, NASA scientists said that Voyager 1 had reached the heliosheath, the boundary that marks the edge of the solar system. It is expected to pass through into interstellar space in 2015, becoming the first man-made object ever to leave the Sun’s orbit.

Kepler telescope
In March, the Kepler Mission was launched with the express goal of finding Earth-like planets around other stars.

It is designed to find small planets by watching stars closely to see if they suddenly get dimmer, indicating that something has passed in front of them. For an Earth-sized planet, that would mean the star becoming dimmer by just 0.01 per cent.

The Wow! signal and Radio source SHGb02+14a
In 1977, an astronomer with SETI spotted an unusual radio signal while working on a radio telescope at Ohio State University. He was so excited by it that he wrote “Wow!” in the margin of the printout.

However, it was never spotted again. After he had calmed down, the discoverer Dr Jerry R Ehman said he believed it was “an Earth-sourced signal that simply got reflected off a piece of space debris.”

Another candidate for evidence of alien life was SHGb02+14a, a signal spotted three times in March 2003. It was at a frequency expected to be used by extraterrestrials – the frequency at which hydrogen absorbs and emits photons.

However, again there were reasons to be sceptical, not least that it came from a direction in which there are no stars for 1000 light years. While impossible to rule out extraterrestrial origin, it may have been a distorted signal from a pulsar, or just random noise.

SETI@home
In the 21st century the search for extraterrestrial life continues in hundreds of thousands of bedrooms and offices around the world.

Launched in 1999, SETI@home is the name given to a virtual supercomputer made of huge numbers of internet-linked home computers. Anybody can download the software and allow SETI to use their spare processing power to scour data from radio telescopes for evidence of alien intelligence.

In terms of power it is the fourth most powerful computer on the planet. It was this network of home computers that spotted SHGb02+14a, and one NASA scientist has predicted that it will find an alien signal by 2025.

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http://www.telegraph.co.uk/science/science-news/6240998/SETI-at-50-10-key-moments-in-the-search-for-extraterrestrial-life.html

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Comments: 2

· Very well put article, thanks.
I'd like to point out that's not 'Aricebo', but 'Arecibo'.

http://www.naic.edu/

;)

Thade

on September 30, 2009

at 08:19 AM

Report this comment

· Though the search for extraterrestrial life is among the most uncertain of all explorations, for me it's also among the very most exciting. That's why I joined the SETI@home network early on, as soon as I learned about it.

My interest comes as the result of two early influences -- I was born in 1951.

First was my discovery of the Tom Swift series, which sucked me headlong into science fiction, of which I remain fond to this day.

The second is far more mundane. I was born with acute short-sightedness, but my paprents didn't realize it until I was in kindergarten.

I'll never forget the first time I saw the stars. But even before that, on the way home from getting my glasses, I marveled at . . . everything. I hadn't known that leaves were individual leaves while still in the trees -- I thought they were solid blobs that fell apart in the autumn.

By the time I was seven or eight, I had my first cheap telescope -- and spent thousands of hours with it and its successors in the years to come.

Always wondering, wondering . . .

There's a serious aspect we have to think about, even if we do discover life elsewhere, or if life elsewhere comes here and they make themselves known (as in a UFO). That's this: who among us wants to be the one to go before the global media to say, "By the way, there's another, more advanced civilisation around a star a few light years away." Or even, "We got a radio signal from a civilization on that star."

If they came *here* -- we can't defend our skies if they turn out to have ill intent? And even if they're as stuck around their star as we are ours -- what does the knowledge that we're not alone mean for human civilisation? For religions?

I'm American, and happened to meet a very high-ranking US Air Force general in a social setting, and this topic arose. He posed those questions to me, assuming the role of a reporter, using a pen as a "microphone," asking, "Well, Mr. President, what does it MEAN??? Can't the Air Force protect us?" And so on.

I can imagine were I President, I might tell whoever brought me the news, "Uh -- let's sit on that. Like a long time while we get the great thinkers together to figure this out."

I'm not a great thinker -- but sure would love to get the call!

http://www.telegraph.co.uk/science/science-news/6240998/SETI-at-50-10-key-moments-in-the-search-for-extraterrestrial-life.html

National ignition facility-2

Thu, 05 Nov 2009 13:54:17 +0100

National Ignition Facility

From Wikipedia, the free encyclopedia

Jump to: navigation, search

NIF's basic layout. The laser pulse is generated in the room just right of center, and is sent into the beamlines (blue) on either side. After several passes through the beamlines the light is sent into the "switchyard" (red) where it is aimed into the target chamber (silver). Three football fields could fit inside NIF.

The National Ignition Facility, or NIF, is a laser-based inertial confinement fusion (ICF) research device located at the Lawrence Livermore National Laboratory in Livermore, California. NIF uses powerful lasers to heat and compress a small amount of hydrogen fuel to the point where nuclear fusion reactions take place. NIF is the largest and most energetic ICF device built to date, and the first that is expected to reach the long-sought goal of "ignition", producing more energy than was put in to start the reaction.

Construction began in 1997 but was fraught with problems and ran into a series of delays that greatly slowed progress into the early 2000s. Progress since then has been much smoother, but compared to initial estimates, NIF is five years behind schedule and almost four times more expensive than budgeted. The construction of the National Ignition Facility was certified complete on 31 March 2009 by the U.S. Department of Energy^[1], and a dedication ceremony took place on 29 May 2009.^[2] The first large-scale laser target experiments were performed in June 2009^[3] and ignition experiments are expected to begin in 2010.^[4]

Contents

[hide]

1 Description

2 History

[edit] Description

[edit] Background

Main article: ICF mechanism

Inertial confinement fusion (ICF) devices use "drivers" to rapidly heat the outer layers of a "target" in order to compress it. The target is a small spherical pellet containing a few milligrams of fusion fuel, typically a mix of deuterium and tritium. The heat of the laser burns the surface of the pellet into a plasma, which explodes off the surface. The remaining portion of the target is driven inwards due to Newton's Third Law, eventually collapsing into a small point of very high density. The rapid blowoff also creates a shock wave that travels towards the center of the compressed fuel from all sides. When it reaches the center of the fuel, a small volume is further heated and compressed to a great degree. If the temperature and density of that small spot can be raised high enough, fusion reactions will occur.^[5]

The fusion reactions release high-energy particles, some of which (primarily alpha particles) collide with the high density fuel around it and slow down. This heats the fuel further, and can potentially cause that fuel to undergo fusion as well. Given the right overall conditions of the compressed fuel—high enough density and temperature—this heating process can result in a chain reaction, burning outward from the center where the shock wave started the reaction. This is a condition known as "ignition", which can lead to a significant portion of the fuel in the target undergoing fusion, and the release of significant amounts of energy.^[6]

To date most ICF experiments have used lasers to heat the targets. Calculations show that the energy must be delivered quickly in order to compress the core before it disassembles, as well as creating a suitable shock wave. The energy must also be focused extremely evenly across the target's outer surface in order to collapse the fuel into a symmetric core. Although other "drivers" have been suggested, notably heavy ions driven in particle accelerators, lasers are currently the only devices with the right combination of features.^[7]^[8]

[edit] Driver laser

NIF aims to create a single 500 terawatt (TW) flash of light that reaches the target from numerous directions at the same time, within a few picoseconds. The design uses 192 individual "beamlets", which are amplified in 48 beamlines containing 16 laser amplifiers per line, each one amplifying four of the beamlets.^[5]

To ensure that the output of the beamlines is uniform, the initial laser light is amplified from a single source in the Injection Laser System (ILS). This starts with a low-power flash of 1053 nanometers (nm) infra-red light generated in an ytterbium-doped optical fiber laser known as the Master Oscillator.^[9] The light from the Master Oscillator is split and directed into 48 Preamplifier Modules (PAMs). The PAMs pass the light four times through a circuit containing a neodymium glass amplifier similar to (but much smaller than) the ones used in the main beamlines, boosting the nanojoules of light created in the Master Oscillator to about 6 joules. According to LLNL, the design of the PAMs was one of the major stumbling blocks during construction. Improvements to the design since then have allowed them to surpass their initial design goals.^[10]

Simplified diagram of the beampath of a NIF laser beam, one of 48 similar beamlines. On the left are the amplifiers and optical switch, and on the right is the final spatial filter, switchyard and optical frequency converter.

The main amplification takes place in a series of glass amplifiers located at one end of the beamlines. Before "firing", the amplifiers are first optically pumped by a total of 7,680 xenon flash lamps (the PAMs have their own smaller flash lamps as well). The lamps are powered by a capacitor bank which stores a total of 400 megajoules (MJ) of electrical energy. When the wavefront passes through them, the amplifiers release some of the light energy stored in them into the beam. This is not a particularly efficient process and less than a quarter of the stored energy is transferred into the beam as it passes through; to improve the energy transfer the beams are sent though the main amplifier section four times, using an optical switch located in a mirrored cavity. In total these amplifiers boost the original 6 J provided by the PAMs to a nominal 4 MJ.^[5] Given the time scale of a few billionths of a second, the power is correspondingly very high, 500 TW.

After the amplification is complete the light is "switched" back into the beamline, where it runs to the far end of the building to the Target Chamber. The total length of the laser from one end to the other is about 1,000 feet (305 meters). A considerable amount of this length is taken up by "spatial filters", small telescopes that focus the laser beam down to a tiny point, with a mask cutting off any stray light outside the focal point. The filters ensure that the image of the beam when it reaches the target is extremely uniform, removing any light that was mis-focussed by imperfections in the optics upstream. Spatial filters were a major step forward in ICF work when they were introduced in the Cyclops laser, an earlier LLNL experiment. The various optical elements in the beamlines are generally packaged into Line Replaceable Units (LRUs), standardized boxes about the size of a small car that can be dropped out of the beamline for replacement from below.^[11]

Just before reaching the Target Chamber the light is reflected off various mirrors in the switchyard in order to impinge on the target from different directions. Since the length of the overall path from the Master Oscillator to the target is different for each of the beamlines, optics are used to "slow" the light in order to ensure all of them reach the center within a few picoseconds of each other.^[12] As can be seen in the layout diagram above, NIF normally directs the laser into the chamber from the top and bottom. The target area and switchyard system can be reconfigured by moving half of the 48 beamlines to alternate positions closer to the equator of the target chamber.

A large KDP crystal grown at LLNL to be cut into slices and used on NIF for frequency conversion from the IR fundamental line at 1053 nm to UV at 351 nm.

One of the last steps in the process before reaching the target chamber is to convert the infrared light at 1053 nm into the ultraviolet (UV) at 351 nm in a device known as a frequency converter.^[13] These are made of thin sheets cut from a single crystal of potassium dihydrogen phosphate. When the 1053 nm (IR) light passes through the first of two of these sheets, frequency addition converts a large fraction of the light into 527 nm light (green). On passing through the second sheet, frequency combination converts much of the 527 nm light and the remaining 1053 nm light into 351 nm (UV) light. IR light is much less effective than UV at heating the targets, because IR couples more strongly with hot electrons which will absorb a considerable amount of energy and interfere with compressing the target. The conversion process is about 50% efficient, reducing delivered energy to a nominal 1.8 MJ.^[14]

One important aspect of any ICF research project is ensuring that experiments can actually be carried out on a timely basis. Previous devices generally had to cool down for hours to allow the flashlamps and laser glass to regain their shapes after firing-caused thermal expansion, limiting use to one or fewer firings a day. One of the goals for NIF is to reduce this time to 5 hours, in order to allow 700 firings a year.^[15]

[edit] NIF and ICF

Laser energy to hohlraum x-ray to target capsule energy coupling efficiency. Note the "laser energy" is after conversion to UV, which loses about 50% of the original IR power.

The name "National Ignition Facility" refers to the goal of "igniting" the fusion fuel, a long-sought threshold in fusion research. In existing (non-weapon) fusion experiments the heat produced by the fusion reactions rapidly escapes from the plasma, meaning that external heating must be applied continually in order to keep the reactions going. "Ignition" refers to the point at which the energy given off in the fusion reactions currently underway is high enough to cause fusion reactions in the surrounding fuel. This causes a chain-reaction that allows the majority of the fuel to undergo a nuclear "burn". Ignition is considered a key requirement if fusion power is to ever become practical.^[6]

NIF is designed primarily to use the indirect drive method of operation, in which the laser heats a small metal cylinder instead of the capsule inside it. The heat causes the cylinder, known as a hohlraum (German for "hollow room", or cavity), to re-emit the energy as intense X-rays, which are more evenly distributed and symmetrical than the original laser beams. Experimental systems, including the OMEGA and Nova lasers, validated this approach through the late 1980s.^[16] In the case of the NIF, the large delivered power allows for the use of a much larger target; the baseline pellet design is about 2 mm in diameter, chilled to about 18 degrees above absolute zero and lined with a layer of solid deuterium-tritium (DT) fuel. The hollow interior also contains a small amount of DT gas.

This conversion process is fairly efficient; of the original ~4 MJ of laser energy created in the beamlines, 1.8 MJ is left after conversion to UV, and about half of the remainder is lost in the x-ray conversion in the hohlraum. Of the rest, perhaps 10 to 20% of the resulting x-rays will be absorbed by the outer layers of the target (see image below).^[17] The shockwave created by this heating absorbs about 140 kJ, which is expected to compress the fuel in the center of the target to a density of about 1,000 g/mL (or 1,000,000 kg/m³);^[18] for comparison, lead has a normal density of about 11 g/mL (11,340 kg/m³). It is expected this will cause about 20 MJ of fusion energy to be released.^[17] Improvements in both the laser system and hohlraum design are expected to improve the shockwave to about 420 kJ, in turn improving the fusion energy to about 100 MJ.^[18] However, the baseline design allows for a maximum of about 45 MJ of fusion energy release, due to the design of the target chamber.^[19] This is the equivalent of about 11 kg of TNT exploding.

Mockup of the gold-plated hohlraum designed for the NIF.

NIF's fuel "target", filled with either D-T gas or D-T ice. The capsule is held in the hohlraum using thin plastic webbing.

NIF is also exploring new types of targets. Previous experiments generally used plastic ablators, typically polystyrene (CH). NIF's targets are constructed by coating a plastic form in a layer of sputtered beryllium or beryllium-copper alloys, and then oxidizing the plastic out of the center.^[20]^[21] In comparison to traditional plastic targets, beryllium targets offer higher density, high transparency to x-rays, and high thermal conductivity. All of these are advantageous in the indirect-drive mode where the incoming energy is in the form of x-rays. They also have a higher leftover ablative mass compared to the fuel inside, which has the benefit of being less sensitive to instability growth from the roughness of the DT ice (although plastic targets of the same mass also show this effect). A more practical benefit is that the mechanical strength of a Be target is high enough to contain the fuel in gaseous form at room temperature. This could allow the targets to be filled with fuel and stored for periods before being chilled to freeze the DT just before firing. In practice, however, the ice has to be carefully grown from an initial seed.^[22]

Although NIF was primarily designed as an indirect drive device, the energy in the laser is high enough to be used as a direct drive system as well, where the laser shines directly on the target. Even at UV wavelengths the power delivered by NIF is estimated to be more than enough to cause ignition, resulting in fusion energy gains of about forty times,^[23] somewhat higher than the indirect drive system. In this case the value of the Be target is reduced and more traditional plastic targets are more appropriate. A more uniform beam layout suitable for direct drive experiments can be arranged through changes in the switchyard that move half of the beamlines to locations closer to the middle of the target chamber.

It has been shown, using scaled implosions on the OMEGA laser and computer simulations, that NIF should also be capable of igniting a capsule using the so-called polar direct drive (PDD) configuration where the target is irradiated directly by the laser, but only from the top and bottom.^[24] In this configuration the target suffers either a "pancake" or "cigar" anisotropy on implosion, reducing the maximum temperature at the core. However, the amount of energy being dumped into the target by the laser is so high that it ignites anyway. Fusion gains in this configuration are estimated to be anywhere between ten and thirty times; less than the symmetrical direct-drive approach, but obtainable with no changes to the NIF beamline layout.

Other targets, called saturn targets, are specifically designed to reduce the anisotropy and improve the implosion.^[25] They feature a small plastic ring around the "equator" of the target, which quickly vaporizes into a plasma when hit by the laser. Some of the laser light is refracted through this plasma back towards the equator of the target, evening out the heating. Ignition with gains of just over thirty-five times are thought to be possible using these targets at NIF,^[24] producing results almost as good as the fully symmetric direct drive approach.

[edit] History

[edit] Impetus

LLNL's history with the ICF program starts with physicist John Nuckolls, who predicted in 1972 that ignition could be achieved with laser energies about 1 kJ, while "high gain" would require energies around 1 MJ.^[26]^[27] Although this sounds very low powered compared to modern machines, at the time it was just beyond the state of the art, and led to a number of programs to produce lasers in this power range. LLNL decided early on to concentrate on glass lasers, while other facilities studied gas lasers using carbon dioxide (e.g. Toward Limitless Energy: National Ignition Facility Focus Of Symposium

ScienceDaily (Aug. 20, 2009) — Chemists are preparing to play an important but often unheralded role in determining the success of one of the largest and most important scientific experiments in history — next year's initial attempts at the National Ignition Facility (NIF) to produce the world's first controlled nuclear fusion reaction. If successful in taming the energy source of the sun, stars, and of the hydrogen bomb, scientists could develop a limitless new source of producing electricity for homes, factories, and businesses.

See also:

Matter & Energy

Reference

The experiment could also lead to new insights into the origins of the universe. A special two-day symposium addressing this topic, "Nuclear Diagnostics in Fusion Energy Research," will be presented Aug. 19 and 20 during the 238th National Meeting of the American Chemical Society (ACS).

Scientists have been trying to achieve controlled nuclear fusion for almost 50 years. In 2010, researchers at the NIF at Lawrence Livermore National Laboratory in California will focus the energy of 192 giant laser beams onto a pea-sized target filled with hydrogen fuel. These lasers represent the world's highest-energy laser system. The scientists hope that their effort will ignite, or fuse, the hydrogen atoms' nuclei to trigger the high energy reaction.

"Chemists will definitely play a role in determining whether nuclear fusion reactions have occurred during this NIF experiment, which is key to determining whether the experiment is a success," says Dawn Shaughnessy, Ph.D., a scientist with Lawrence Livermore National Laboratory.

"The idea is that the lasers will fuse hydrogen particles together, producing neutrons," says Shaughnessy, one of many scientists who plan to analyze materials produced by the reaction. "We'll collect and measure the materials produced from the ignition and hopefully be able to determine how many neutrons were made. More neutrons mean that more fusion has occurred."

First Experiments On National Ignition Facility Validate Computer Simulations On Road To Ignition

ScienceDaily (Dec. 4, 2005) — Researchers at Lawrence Livermore National Laboratory (LLNL) have successfully conducted an important round of successful laser experiments at the National Ignition Facility (NIF), validating key computer simulations and theoretical projections relevant to the plasma and X-ray environment necessary to achieve ignition.

See also:

Matter & Energy

Reference

NIF, which is more than 80 percent complete, is a 10-story building in which 192 laser beams are focused on a tiny target inside a 30-foot diameter aluminum-lined chamber. Eight beams already have been commissioned. When fully operational (currently scheduled for mid-2009), NIF will be used to study and achieve ignition, resulting in a brief burst of energy that is greater than was used in its creation. Ignition is a long-sought achievement that has never occurred under controlled conditions in a laboratory setting.

The series of experiments is described in a Nov. 18 Physical Review Letters article, whose lead author was the Lab’s Eduard Dewald.

NIF’s first four beams were fired into various-sized gold-plated cylinders known as hohlraums, only a few millimeters long. The laser beams entered the hohlraums through a single hole at one end. In the future NIF ignition experiments, the deuterium-tritium fuel capsule will be placed inside a larger hohlraum. All 192 NIF laser beams will then heat the interior of the hohlraum, through holes on both ends, creating X-rays that ablate (burn off) and implode the capsule to ignition.

Although the beams of high-power ultraviolet laser light only lasted a maximum of nine nanoseconds (billionths of a second), that’s considered long to ignition researchers. Such sustained pulses are a capability that is unique to NIF.

Various diagnostic instruments measured the X-ray spectra and radiation temperatures inside the hohlraum, and imaged the X-rays that were sufficiently energetic to exit through the hohlraum wall. Snapshots of the X-rays provide a clear picture of how the plasma inside the hohlraum evolves.

One goal of these experiments was to demonstrate that NIF, even at this very early stage, is capable of spanning the full range of hohlraum radiation temperatures needed for ignition. The goal was clearly achieved with a series of different-sized hohlraums irradiated with two-nanosecond laser pulses of about eight trillion watts, which produced radiation temperatures in agreement with both theoretical expectations and previous experience from other facilities.

Additionally, the researchers wanted to fire some of these “very long” laser pulses into relatively small hohlraums in order to test computational and theoretical models of when a given hohlraum becomes extremely filled with plasma.

The NIF experiments validated those predictions, with multiple diagnostic instruments registering results almost exactly as expected. These findings are important because they confirm that the larger hohlraums that will be used for NIF ignition experiments should develop plasma more slowly, an important factor in controlling proper symmetry of the implosion necessary for ignition.

“This was a very clear demonstration that NIF is indeed on the path toward ignition,” said Eduard Dewald, the physicist who led the series of seven experiments in September 2004. “The precise data we were able to acquire proved in real terms that the computer projections are remarkably accurate in their predictions. Furthermore, NIF is capable of producing high-quality laser beams that met nearly all of our design specifications.”

The researchers point out that their results can be extrapolated to higher laser energies by "applying a simple analytic model for radiation temperature limits." In other words, even though the initial experiments were limited to the first four NIF beams and only about 1 percent of NIF's ultimate 1.8 megajoule energy output, the scientists now have good reason to anticipate hohlraum experiments that are hotter, larger and of longer duration when all of NIF's 192 beams are fully operational.

“What amazed me most was that this was the first time in my 25 years of doing laser experiments here at the Lab, that everything proceeded absolutely perfectly the first time we tried it,” said Larry Suter, principle designer of the experiments and co-author of the journal article. “It’s a real testament to the effort and the quality control of the NIF team.”

The series of experiments was the first hohlraum campaign on NIF and part of a larger four-campaign effort, coordinated by LLNL’s Nino Landen, and involving researchers from LLNL, Los Alamos National Laboratory, the United Kingdom’s Atomic Weapons Establishment (AWE), and General Atomics.

Founded in 1952, Lawrence Livermore National Laboratory has a mission to ensure national security and apply science and technology to the important issues of our time. Lawrence Livermore National Laboratory is managed by the University of California for the U.S. Department of Energy’s National Nuclear Security Administration.

v For more details visit:

1) http://www.sciencedaily.com/news/matter_energy/

2) http://www.sciencedaily.com/articles/

ITER reactor

Thu, 05 Nov 2009 13:47:30 +0100

ITER

From Wikipedia, the free encyclopedia

Jump to: navigation, search

Cut-away of a model of the ITER Vacuum Vessel showing part of the 440 Blanket modules attached to the inner wall and the Divertor cassettes at the bottom

ITER (originally the International Thermonuclear Experimental Reactor) is an international tokamak (magnetic confinement fusion) research/engineering project that could help to make the transition from today's studies of plasma physics to future electricity-producing fusion power plants. It builds on research done with devices such as DIII-D, EAST,ADITYA, KSTAR, TFTR, ASDEX Upgrade, Joint European Torus, JT-60, Tore Supra and T-15.

Contents

[hide]

9.1 Response to criticism

[edit] Background

On November 21, 2006, the seven participants formally agreed to fund the creation of a nuclear fusion reactor.^[1] The program is anticipated to last for 30 years – 10 for construction, and 20 of operation. ITER was originally expected to cost approximately €5bn, but the rising price of raw materials and changes to the initial design may see that amount double.^[2] The reactor is expected to take nearly 10 years to build and is scheduled to be switched on in 2018.^[2] If completed, ITER would be one of the most expensive modern technoscientific megaprojects. Site preparation has begun in Cadarache, France and procurement of large components has started.^[3]

ITER is designed to produce approximately 500 MW of fusion power sustained for up to 1,000 seconds^[4] (compared to JET's peak of 16 MW for less than a second) by the fusion of about 0.5 g of deuterium/tritium mixture in its approximately 840 m³ reactor chamber. Although ITER is expected to produce (in the form of heat) 5-10 times more energy than the amount consumed to heat up the plasma to fusion temperatures, the generated heat will not be used to generate any electricity.

In assessing the potential for global and sustainable energy production in the long term it is clear that the diminishing availability and rising cost of energy based on carbon combined with the increased emphasis on low environmental impact energy sources generally, emphasizes the notion that nuclear fusion is one of very few candidates for the large-scale carbon-free production of base-load power.

Fusion has many potential attractions, as it is considered to be essentially unlimited, intrinsically safe, widely available, using cheap fuel with no production of CO₂ or atmospheric pollutants and producing relatively short-lived waste. ITER was originally an acronym for International Thermonuclear Experimental Reactor, but that title was dropped due to the negative popular connotation of "thermonuclear," especially when in conjunction with "experimental". "Iter" also means "journey", "direction" or "way" in Latin,^[5] reflecting ITER's potential role in harnessing nuclear fusion as a peaceful power source.

[edit] Objectives

ITER's mission is to demonstrate feasibility of fusion power, and prove that it can work without negative impact.^[6] Specifically, this includes:

To momentarily produce ten times more thermal energy from fusion heating than is supplied by auxiliary heating (a Q value of 10).
To produce a steady-state plasma with a Q value greater than 5.
To maintain a fusion pulse for up to eight minutes.
To ignite a 'burning' (self-sustaining) plasma.
To develop technologies and processes needed for a fusion power plant — including superconducting magnets and remote handling (maintenance by robot).
To verify tritium breeding concepts.
To refine neutron shield/heat conversion technology (most of energy in the D+T fusion reaction is released in the form of fast neutrons).

[edit] Reactor overview

See also: Nuclear fusion

When deuterium and tritium fuse, two nuclei come together to form a helium nucleus (an alpha particle), and a high-energy neutron.

While in fact nearly all stable isotopes lighter on the periodic table than iron will fuse with some other isotope and release energy, deuterium and tritium are by far the most attractive for energy generation as they require the lowest activation energy (thus lowest temperature) to do so.

All proto- and mid-life stars radiate enormous amounts of energy generated by fusion processes. Mass for mass, the deuterium-tritium fusion process releases roughly three times as much energy as uranium 235 fission, and millions of times more energy than a chemical reaction such as the burning of coal. It is the goal of a fusion power plant to harness this energy to produce electricity.

The activation energy for fusion is so high because the protons in each nucleus will tend to strongly repel one another, as they each have the same positive charge. A heuristic for estimating reaction rates is that nuclei must be able to get within 100 femtometer (1 × 10⁻¹³ meter) of each other, where the nuclei are increasingly likely to undergo quantum tunnelling past the electrostatic barrier and the turning point where the strong nuclear force and the electrostatic force are equally balanced, allowing them to fuse. In ITER, this distance of approach is made possible by high temperatures and magnetic confinement. High temperatures give the nuclei enough energy to overcome their electrostatic repulsion (see Maxwell-Boltzmann distribution). For deuterium and tritium, the optimal reaction rates occur at temperatures on the order of 100,000,000 K. The plasma is heated to a high temperature by ohmic heating (running a current through the plasma). Additional heating is applied using neutral beam injection (which cross magnetic field lines without a net deflection and will not cause a large electromagnetic disruption) and radio frequency (RF) or microwave heating.

At such high temperatures, particles have a vast kinetic energy, and hence velocity. If unconfined, the particles will rapidly escape, taking the energy with them, cooling the plasma to the point where net energy is no longer produced. A successful reactor would need to contain the particles in a small enough volume for a long enough time for much of the plasma to fuse. In ITER and many other magnetic confinement reactors, the plasma, a gas of charged particles, is confined using magnetic fields. A charged particle moving through a magnetic field experiences a force perpendicular to the direction of travel, resulting in centripetal acceleration, thereby confining it to move in a circle.

A solid confinement vessel is also needed, both to shield the magnets and other equipment from high temperatures and energetic photons and particles, and to maintain a near-vacuum for the plasma to populate. The containment vessel is subjected to a barrage of very energetic particles, where electrons, ions, photons, alpha particles, and neutrons constantly bombard it and degrade the structure. The material must be designed to endure this environment so that a powerplant would be economical. Tests of such materials will be carried out both at ITER and at IFMIF (International Fusion Materials Irradiation Facility).

Once fusion has begun, high energy neutrons will radiate from the reactive regions of the plasma, crossing magnetic field lines easily due to charge neutrality (see neutron flux). Since it is the neutrons that receive the majority of the energy, they will be ITER's primary source of energy output. Ideally, alpha particles will expend their energy in the plasma, further heating it.

Beyond the inner wall of the containment vessel one of several test blanket modules will be placed. These are designed to slow and absorb neutrons in a reliable and efficient manner, limiting damage to the rest of the structure, and breeding tritium from lithium and the incoming neutrons for fuel. Energy absorbed from the fast neutrons is extracted and passed into the primary coolant. This heat energy would then be used to power an electricity-generating turbine in a real power plant; however, in ITER this heat is not of scientific interest, and will be extracted and disposed.

[edit] History

ITER began in 1985 as a collaboration between the European Union (through EURATOM), the USA, the then Soviet Union, and Japan. Conceptual and engineering design phases led to an acceptable, detailed design in 2001, underpinned by US$650 million worth of research and development by the "ITER Parties" to establish its practical feasibility. These parties (with the Russian Federation replacing the Soviet Union and with the USA opting out of the project in 1999 and returning in 2003) were joined in negotiations on the future construction, operation and decommissioning of ITER by Canada (who then terminated their participation at the end of 2003), the People's Republic of China, and the Republic of Korea. India officially became part of ITER on 6 December 2005.

On 28 June 2005, it was officially announced that ITER will be built in the European Union in Southern France. The negotiations that led to the decision ended in a compromise between the EU and Japan, in that Japan was promised 20% of the research staff on the French location of ITER, as well as the head of the administrative body of ITER. In addition, another research facility for the project will be built in Japan, and the European Union has agreed to contribute about 50% of the costs of this institution.^[7]

On 21 November 2006, an international consortium signed a formal agreement to build the reactor.^[8]

On 24 September 2007, the People's Republic of China became the seventh party who had deposited the ITER Agreement to the IAEA.

On 24 October 2007, the ITER Agreement entered into force and the ITER Organization legally came into existence.

ITER will run in parallel with a materials test facility, the International Fusion Materials Irradiation Facility (IFMIF), which will develop materials suitable for use in the extreme conditions that will be found in future fusion power plants. Both of these will be followed by a demonstration power plant, DEMO, which would generate electricity. DEMO would be the first to produce electric energy for commercial use.

A "fast track" plan to a commercial fusion power plant has been sketched out.^[9] This scenario, which assumes that ITER continues to demonstrate that the tokamak line of magnetic confinement is the most promising for power generation, anticipates a full-scale power plant coming on-line in 2050, potentially leading to a large-scale adoption of fusion power over the following thirty years.

[edit] Technical design

Selected facts: The central solenoid coil will use superconducting niobium-tin, to carry 46 kA and produce a field of 13.5 teslas. The 18 toroidal field coils will also use niobium-tin. At maximum field of 11.8 T they will store 41 GJ. They have been tested at a record 80 kA. Other lower field ITER magnets (PF and CC) will use niobium-titanium.

[edit] Location

Location of Cadarache, France, EU

The process of selecting a location for ITER was long and drawn out. The most likely sites were Cadarache in Provence-Alpes-Côte-d'Azur, France and Rokkasho, Aomori, Japan. Additionally, Canada announced a bid for the site in Clarington in May 2001, but withdrew from the race in 2003. Spain also offered a site at Vandellòs on 17 April 2002, but the EU decided to concentrate its support solely behind the French site in late November 2003. From this point on, the choice was between France and Japan.

On 3 May 2005, the EU and Japan agreed to a process which would settle their dispute by July.

At the final meeting in Moscow on 28 June 2005, the participating parties agreed on the site in Cadarache in Provence-Alpes-Côte-d'Azur, France.

Construction of the ITER complex began in 2008, while assembly of the tokamak itself is scheduled to begin in the year 2011.^[10]

[edit] Participants

Currently there are seven national and supranational parties participating in the ITER program: the European Union (EU; see Fusion for Energy), India, Japan, People's Republic of China,

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