tagged w/ Particle Accelerator
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Los Angeles Times...
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CONVERSATIONS IN SCIENCE
Tevatron particle accelerator shuts down
Physicist Giovanni Punzi discusses the 4-mile-long accelerator and its shutdown after 26 years of smashing atoms.
PHOTO:
The massive Tevatron particle accelerator at the Fermi National Accelerator Laboratory in Batavia, Ill., has powered down after 26 years of smashing atoms together.
(Fermilab / October 1, 2011)
By Eryn Brown, Los Angeles Times
October 1, 2011
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After smashing atoms together for 26 years, the Tevatron particle accelerator powered down on Friday. The 4-mile-long ring-shaped accelerator, located at the Fermi National Accelerator Laboratory in Batavia, Ill., was built to hurl tiny bits of matter at each other in the hopes that they would break apart into the basic building blocks of the universe. Though the Tevatron made major discoveries, it became essentially obsolete after the Large Hadron Collider in Geneva began conducting experiments in 2009.
University of Pisa physicist Giovanni Punzi has worked at the Tevatron since it generated its first collisions in 1985. He talked about the Tevatron on Wednesday, two days before it was shut down.
What made the Tevatron special?
The Tevatron was the highest-energy collider in operation for a very long time.
What does the Tevatron do?
It collides protons and antiprotons. We have particle detectors situated where we can analyze the products of these collisions and find what new particles are there.
Why would you want to do this?
When you get the highest possible energy in collisions of particles, you reproduce a level of energy that doesn't exist today. It only existed at a very early stage in the universe, after the big bang. Creating such energies lets you see new phenomena — including particles that are not found in ordinary matter. So you can study the very basic laws that underlie everything we see and are at the basis of the evolution of the universe.
It's a frontier of knowledge. You get to see things that have never been seen.
What did the Tevatron find that had never been seen?
A number of observations and precision measurements that have added to our understanding of high-energy physics. And the top quark was discovered here in 1995. That was a very big discovery.
Why was it important to find the top quark?
The top quark was crucial because without it, all of our theories of how subatomic particles behave wouldn't work. Quarks are the fundamental particles that combine to make protons and neutrons, and physicists knew there had to be a sixth quark. Everybody was puzzled by the fact that we couldn't find it. The reason we couldn't find it is because its mass was so large that scientists could not produce it until the Tevatron came along.
It was a very long search. If we had not found the top quark, understanding all of the rest of the physics would have been a problem.
How did physicists study basic particles before the Tevatron was built?
Before this machine they had proton-antiproton colliders at CERN [the European Organization for Nuclear Research] in Geneva, but they operated at lower energies.
I remember people saying it would be impossible to put together a thousand magnets and make them work at the same time. But the people here did it. People get used to the idea of doing something that yesterday was considered impossible. It pushes everybody to their best.
Now, of course, the record is going back to Geneva because CERN has built an even bigger machine — the Large Hadron Collider. It's 31/2 times more energetic than the Tevatron.
The Tevatron played a big role in the search for the elusive Higgs boson, the so-called "God particle" that gives rise to mass.
Yes — the Tevatron was able to restrict the possible mass of the Higgs boson to quite a small range.
And even though the collider will no longer operate, you'll continue that search?
Yes. We've used just a fraction of the data we have, and we've been improving analysis techniques over time. So now we want to give it our best possible shot and see what we can figure out about the Higgs boson.
The Large Hadron Collider is also looking for the Higgs. But we look for different modes of decay of the Higgs boson: two different faces of the same coin. Even if the Higgs is seen in Geneva, being able to see it here will be very important to confirm and to understand the nature of this particle, which up to now is completely mysterious. We will be certainly adding to the knowledge of this thing.
Who decided to shut down the Tevatron?
The Department of Energy (which operates Fermilab) and the lab directors decided it was time to go into new projects. We proposed last year to keep going and take some more data, but the decision was to begin exploring what's known as the "intensity frontier."
What does that mean?
Rather than going for the highest-possible energy of collisions, we will go for very intense beams with very large numbers of particles. Using these, Fermilab will produce a large number of collisions that will let scientists look for very rare processes. What they cannot make in terms of energy they try to make up in terms of intensity and frequency of the collisions.
There are a whole lot of things that have been developed here, especially on the side of neutrino physics, that require very intense beams.
Last week, physicists at CERN reported that they had measured neutrinos traveling faster than the speed of light. Scientists around the world are now trying to see if they can replicate that result — including a team at Fermilab, right?
Yes. This raised lots of discussion. Most of us were thinking this is too strange to be true. If it is really true it's a violation of the fundamental laws of physics. It's really beyond anything we've seen in the past.
What will happen during the shutdown on Friday?
We'll simply stop doing what we've been doing. People will turn off the accelerator and turn off our detectors. Then we will concentrate on trying to get the final results from the data we've already collected.
How long will that take?
It depends on how interesting the results are. In principle it can go on for several years without a problem, but I anticipate that most of the things will probably come within a couple of years, no more.
Are people at Fermilab emotional this week?
How can't you be emotional when it's been so long and such a successful program? As I said, we have a group of people who are still willing to do more. People never got bored, for all this time.
How many colliders remain in the world?
Well, we have this very big one in Geneva. Apart from that we have smaller machines for doing specialized kinds of physics.
What will become of the Tevatron itself?
It's my understanding that Fermilab will reuse some pieces for the next accelerator and put others on display in a museum.
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This interview was edited for space and clarity.
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CONVERSATIONS IN SCIENCE
Tevatron particle accelerator... more
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We’re going way beyond innovation here. Instead of the latest technology, we’re getting a tantalising glimpse of something that doesn’t yet exist, but is making exciting progress in the lab and would be responsible for enormous advances in many fields of science and technology if it fulfils its promise.We’re going way beyond innovation here. Instead of the latest technology,... more
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At Particle Lab, a Tantalizing Glimpse Has Physicists Holding Their Breaths
By DENNIS OVERBYE
Published: April 5, 2011
Physicists at the Fermi National Accelerator Laboratory are planning to announce Wednesday that they have found a suspicious bump in their data that could be evidence of a new elementary particle or even, some say, a new force of nature.
The results, if they hold up, could be a spectacular last hurrah for Fermilab’s Tevatron, once the world’s most powerful particle accelerator and now slated to go dark forever in September or earlier, whenever Fermilab runs out of money to operate it.
“Nobody knows what this is,” said Christopher Hill, a theorist at Fermilab who was not part of the team. “If it is real, it would be the most significant discovery in physics in half a century.”
One possible explanation for this mysterious bump, scientists say, is that it is evidence of a new and unexpected version of the long-sought Higgs boson. This is a hypothetical elementary particle that, according to the reigning theory known as the Standard Model, is responsible for endowing other elementary particles with mass.
Another explanation might be that it is evidence of a new force of nature — in addition to gravity, electromagnetism, and the strong and weak nuclear forces we already know and are baffled by — that would manifest itself only at very short distances like those that rule inside the atomic nucleus.
Either could shake what has passed for conventional wisdom in physics for the last few decades. Or it could be there is something they do not understand about so-called regular physics.
Giovanni Punzi, the Fermilab physicist who is spokesman for the international team that did the work, said by e-mail that he and his colleagues were “strongly thrilled at the possibility, and cautious at the same time, because this would be so important that almost scares us — so we think of all possible alternative explanations.”
Physicists outside the Fermilab circle said they regarded the results, which have been widely discussed in physics circles for several months, with a mixture of awe and skepticism.
“If it holds up, it’s very big,” said Neal Weiner, a theoretical physicist at New York University. Lisa Randall, a theorist at Harvard, said the same thing: “It is definitely interesting, if real.”
But Nima Arkani-Hamed of the Institute for Advanced Study in Princeton, N.J., said he did not find the bump convincing, saying it could be an artifact of how the data was sliced and diced.
The important thing, he said, was that if this and other anomalies recently reported at the Tevatron are real, then the Large Hadron Collider, a rival machine run by CERN, “will see dramatic evidence in not too long — that’s certainly what I’m waiting for.”
The key phrase, everyone agrees, is “if it holds up.” The experimenters estimate that there is a less than a quarter of 1 percent chance their bump is a statistical fluctuation, making it what physicists call a three-sigma result, enough to attract attention but not enough to claim an actual discovery. Three-sigma bumps, as every physicist knows, can come and go.
The Tevatron has been colliding beams of protons and their opposites, antiprotons, that have been accelerated to energies of one trillion electron volts, for more than two decades looking for new forces and particles. The bump showed up in an analysis of some 10,000 of those collisions collected by the Collider Detector at Fermilab, one of two mammoth detectors at the facility, which is outside Chicago.
They found that in about 250 more cases than they expected, what came out of the collision were two jets of lightweight particles, like electrons, and a heavy-force-carrying particle called the W boson were produced. The team found that in about 250 times more cases than expected, the total energy of the jets clustered around a value of about 144 billion electron volts, as if they were the decay products of a hitherto unsuspected particle with that mass-energy. For comparison, a proton weighs about one billion electron volts.
This could not be the Standard Model Higgs, Dr. Punzi and his colleagues concluded, because the Higgs is predicted to decay into much heavier particles, namely quarks. Moreover, the rate at which these mystery particles were being produced was 300 times greater than Higgs bosons would be produced.
If real, it was something totally new, Dr. Punzi said. The result had recently been strengthened, he said, by new calculations of interactions between quarks, which are notoriously difficult to compute. “It is so new, so astonishing, we ourselves can barely believe it,” he said. “We decided we had to let the whole world know.”
Dr. Punzi and his colleagues have submitted a paper that was to be posted on a physics Web site Tuesday night and has been submitted to Physical Review Letters.
Joe Lykken, a Fermilab particle theorist, said Dr. Punzi’s group would have four times as much data in an analysis later this year. “This would be enough to claim a definitive major discovery,” he wrote in an e-mail, “just as the Tevatron — and perhaps Fermilab itself — is being shut down for budget savings.”At Particle Lab, a Tantalizing Glimpse Has Physicists Holding Their Breaths
By DENNIS... more
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When you peel off a strip of Scotch tape, you’re holding a tiny particle accelerator. Think of this during the upcoming holiday season. As you wrap present after present, you’re simultaneously creating an electric field powerful enough to accelerate any free electrons hovering around. Under the right conditions, this can coax the electrons into spewing out X-rays. The good news: As long as you aren’t playing Santa in a vacuum, you don’t need to worry about the radiation exposure—the electrons will bump into air molecules long before they get a chance to start emitting any X-rays. Science News explains:
http://ramanan50.wordpress.com/2011/02/28/make-a-particle-accelerator-with-tape/When you peel off a strip of Scotch tape, you’re holding a tiny particle... more
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Forget the fourth dimension. It appears the third dimension may in fact be nothing more than a holographic illusion, and that the entire universe really exists in just 2D. A 'holometer' is being built by Fermilab to find out for sure.
http://talkingskull.com/article/third-dimension-just-illusionForget the fourth dimension. It appears the third dimension may in fact be nothing... more
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Scientists ask particles to walk a straight line
One of the most expensive and ambitious pieces of scientific equipment in mankind's history, the Large Hadron Collider, has set records, but been fraught with problems. Now, even as operations and analysis of the $9B USD collider start to get back on course, scientists are developing a new collider that will deliver more precise measurements and new insights into the fundamental building blocks of the universe.
The International Linear Collider (ILC) as proposed would stretch 31 kilometers (19 miles, versus the 17-mile circumference of the LHC), with 14,000 electron-positron collisions per second at 500 GeV. That would essentially make it a linear version of the LHC and the world's largest linear collider by far, surpassing the 2-mile-long, 50 GeV Stanford Linear Accelerator.
The new collider will provide unique advantages when colliding electrons and positrons (anti-electrons), which are much lighter than the protons used in the LHC. Circular colliders like the LHC are valuable in that there's no waste of particles -- particles in the beam that "miss" colliding the first time spin back around and eventually will connect. The downside is that by traveling a circular track, the precision of measurements is reduced due to synchrotron radiation, which worsens as the particles get smaller. This means that circular accelerators are best suited for large particles like proton beams.
Linear colliders like the ILC offer a straight shot. If some particles miss, they will be lost. However, the particles will be delivered at full energy, allowing for collisions of smaller particles like the electron-positron pair at a higher level of measurement.
The ILC will use new superconducting radio frequency technology devices recently developed to create these energy levels. Traditionally, accelerators used copper RF cavities that are readily fabricated but suffer large power losses due to induced surface currents. These new superconducting cavities reduce the energy losses to nearly zero. Approximately 16,000 superconducting accelerating cavities made of pure niobium will be used, operating at 2 K (-271.2 °C or -456 °F).
The device is competing with a separately planned CERN linear accelerator dubbed the Compact Linear Collider (CLIC). The CLIC would be much shorter, but much higher energy. Whereas the ILC would offer electron beams of 500 GeV, with an upgrade option to 1 TeV, the CLIC would offer basic beam strength of 3 TeV, with an upgrade option to 5 TeV (by contrast the LHC offers beam strength of 7 TeV for a proton beam).
The problem with the CLIC is feasibility. An immense alternating electric field is necessary to sustain the powerful, compact design. Current technology falls short of being able to produce and safely utilize such a field. The ILC, on the other hand, is less of a dramatic departure from previous designs.
CERN researcher and Director of the Accélérateur Linéaire Laboratory at Orsay (LAL), Guy Wormser will present at the International Conference on High Energy Physics today in Paris about the new design. He states to the UK's Mail Online, "[W]e made a machine which allowed us to make a big leap in understanding, a sort of enlightener, and now we study and detail things and that's the linear collider. It's the future of our discipline."
Regardless of which design is ultimately selected and funded -- the ILC or CLIC -- CERN almost certainly hopes to avoid public relations nightmares like the over-year-long shutdown and $40M USD that the LHC endured. However, when venturing into unexplored territory mistakes are bound to occur. One can only hope they are met with understanding from the public that is ultimately funding these devices, via taxes.
There are large numbers of spin-off technologies involved that will be commercialized. A new generation of Positron Emission Tomography (PET) machines use of medical imaging could be developed, while the large area particle detection systems developed for ILC experiments could provide an effective technology for cargo container inspections either through X-ray excitation or using naturally occurring cosmic radiation.
Although scientists working for CERN are also taking an active role in the ILC project, it is by no means solely a CERN project. Nearly 300 laboratories and universities around the world are involved in the ILC project. Over 700 people are working on the accelerator design itself, while another 900 people are working on detector development.
The U.S. is contributing 10-20% of the estimated $12 billion+ cost, but Japan, China, India and Russia are likely to join the EU as partners. The location of the ILC has not yet been decided, but Fermilab in Illinois is a contender, along with other sites in Japan, Germany, Switzerland and Russia.
The proposal for the ILC came together from three projects: the Next Linear Collider (NLC), the Global Linear Collider (GLC), and the Teraelectronvolt Energy Superconducting Linear Accelerator (TESLA).
The current Technical Design Phase (TDP) is producing a technical design of the project in order to demonstrate its feasibility to all involved governments so the ILC can be approved and eventually built. The Technical Design Report (TDR) will be released at the end of 2012, with construction targeted for completion by 2020.
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Lets all hope Obama follows in Clinton's foot steps and encourages science by getting them to build the next collider here!Scientists ask particles to walk a straight line
One of the most expensive and... more
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"The world's largest particle collider malfunctioned within hours of its launch to great fanfare, but its operator didn't report the problem for a week.
"In a statement Thursday, the European Organization for Nuclear Research reported for the first time that a 30-ton transformer that cools part of the collider broke, forcing physicists to stop using the atom smasher just a day after starting it up last week.
"The faulty transformer has been replaced and the ring in the 17-mile circular tunnel under the Swiss-French border has been cooled back down to near zero on the Kelvin scale — minus 459.67 degrees Fahrenheit — the most efficient operating temperature, said a statement by CERN, as the organization is known.
"When the transformer malfunctioned, operating temperatures rose from below 2 Kelvin to 4.5 Kelvin — extraordinarily cold by most standards, but warmer than the normal operating temperature."
[Click link for rest]"The world's largest particle collider malfunctioned within hours of its... more
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This is what people are paranoid will happen when the CERN particle accelerator is turned on. This is what people are paranoid will happen when the CERN particle accelerator is... more
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As a researcher at the Institute for High Energy Physics in Protvino, Bugorski used to work with the Synchrotron U-70, the largest Soviet particle accelerator. On July 13, 1978, Bugorski was was leaning over checking a malfunctioning piece of equipment when an accident occurred due to failed safety mechanisms while his head was in the path of the proton beam. He claims having seen a light "brighter than a thousand suns", but felt no pain. The beam measured about 200,000 rads when it entered Bugorski's skull, and about 300,000 rads when it exited after irradiating the inside of his head.
The left half of Bugorski's face inflamed and over the next several days started peeling off, showing the path that the proton beam had burned through parts of his face, his bone, and the brain tissue underneath. As it was believed that about 500 to 600 rads is enough to kill a person, Bugorski was taken to a hospital in Moscow where the doctors could oversee his predicted death. However, Bugorski survived and even completed his Ph.D. There was virtually no damage to his cognative abilities, but the fatigue of mental strain increased dramatically. Bugroski lost all hearing in the left ear and only a constant hum remained. The left half of his face was petrified, due to the destruction of nerves, and does not age. He is able to function normally, save the fact that he stuggles with ongoing bouts with petit mal seizures and very rarely grand mal seizures.As a researcher at the Institute for High Energy Physics in Protvino, Bugorski used to... more
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The GRID and the largest and most expensive particle accelerator ever:
"The Times online reported recently that a data communications grid built to transfer data from the world's largest particle accelerator may be able to function as an alternate Internet, with speeds about 10,000 times faster than an average broadband connection. This network - referred to in the article simply as “the grid” - was built with modern fiber optic technology and currently has 55,000 servers connecting the CERN laboratory in Geneva, Switzerland with eleven locations internationally. The grid was built to house the data coming from CERN's newest project: the world's largest particle accelerator. The Large Hadron Collider (LHC) is designed to study the inner workings of matter and perhaps even discover the elusive Higgs Boson particle. Internet history buffs may recall that Sir Tim Berners-Lee invented the World Wide Web in 1989 while researching at CERN."
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Concerning adverse reactions:
"One of their concerns is that the mini-black holes generated by this machine could eventually coalesce into a larger black hole that would then begin absorbing matter. Another possibility is that new combinations of quarks could come into existence, creating a stable, negatively-charged strangelet which could turn everything it touches into strangelets as well – plunging us into a parallel universe of stable, negatively-charged strangelets. Yet another theory is that high-energy collisions in the LHC could result in massive particles that only have one magnetic pole, rather than the typical north-south pole magnetism with which we are familiar. Critics worry that such particles could start a huge chain reaction, converting atoms into different forms of matter."
The GRID and the largest and most expensive particle accelerator ever:
"The... more
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Walter Wagner is pressing for a lawsuit to keep CERN from using their 8 billion dollar Large Hadron Collider to create a scenario of what it was like a trillionth of a second after the big bang, for fear of a tiny black hole or conversion of Earth into strange matter. However, scientists have deemed such scruples insignificant. Let's hear from you: Is Wagner a "crackpot," or is this a genuine problem?Walter Wagner is pressing for a lawsuit to keep CERN from using their 8 billion dollar... more
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Two men, Walter L. Wagner and Luis Sancho, filed a lawsuit in the federal court in Hawaii, contending that scientists at the European Center for Nuclear Research (CERN) played down the chances that a giant particle accelerator could create a tiny black whole (which could eat Earth) or "it could spit out something called a 'strangelet' that would convert our planet to a shrunken dense dead lump of something called 'strange matter.'
World physicist have spent billions of dollars building a this giant particle accelerator, called Large Hadron Collider, in which "colliding protons will recreate energies and conditions last seen a trillionth of a second after the Big Bang. Researchers will sift the debris from these primordial recreations for clues to the nature of mass and new forces and symmetries of nature."
This lawsuit touches on an ongoing issue: How do scientist assess/ estimate the risk of new groundbreaking experiments, and who decides whether or not to go ahead?
Any suggestions?
(check out the article for more details :)
Two men, Walter L. Wagner and Luis Sancho, filed a lawsuit in the federal court in... more
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