Posts Tagged ‘particle accelerators’
Fresh Data From CERN and Tevatron Gives A Glimpse of the God Particle
A picture starts to emerge from the fog
Again, no one is shouting eureka just yet, but taken together, collision data from the Large Hadron Collider and the Tevatron suggest scientists may have seen the first glimpses of the elusive Higgs particle, the grand prize of physics.
At a , the Atlas and CMS teams at the LHC reported finding a large number of interesting particle events between a mass range of 130 and 150 giga-electronvolts (GeV). Then over the weekend, several media outlets reported the DZero and CDF teams at the Tevatron also around 140 GeV.
Though the LHC data is considered to have a higher degree of certainty, neither set of data is close to conclusive, physicists warned. But that didn’t stop several theorists from using words like and
“There might be some picture emerging from the fog,” DZero spokesman Stefan Soldner-Rembold told the BBC.
Even oddsmakers are feeling confident. Today, the Irish bookmaker Paddy Power slashed the odds on the Higgs boson being scientifically proven to exist before the end of 2011 from 12-1 to 1-3.
Both the LHC and Tevatron have been hurtling subatomic particles around a ring, colliding them at huge energies to blast them apart and study the pieces. This has already yielded plenty of interesting physics, including the announcement of a just last week. The point is to prove what’s called the standard model of particle physics, the system of particles and forces that governs the universe. The Higgs boson, named for the physicist who proposed its existence, is the most sought-after piece of the standard model puzzle. The Higgs particle is thought to endow other particles with mass, and it would unify the weak nuclear and electromagnetic forces.
While the Tevatron and LHC have been operating at high power, especially in the past two years, scientists have been studying the remnants of particle collisions to look for signs of the Higgs. They , so they have been able to determine a host of electronvolt ranges in which it doesn’t exist. But the interesting activity at 130-150 GeV suggests it could exist in that range. (Some physicists are arguing the opposite, that the new data shows the Higgs doesn’t exist in that range. Check out this by MSNBC’s Alan Boyle for further explanation.)
Either way, the data will help narrow down the mass-energy ranges in which the Higgs may be found. Within the next year, physicists will either find it or rule out its existence, the director of CERN told the BBC.
The bookies give 5-2 odds on the Higgs being found at 141 to 150 GeV. (You can , if you're so inclined.)
If it doesn’t exist, that means the standard model must be wrong, and that would be very interesting. So either way, the news coming out of the Tevatron and LHC will remain intriguing for some time. Stay tuned.
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Pocket Particle Accelerators Like This One Could Bring Safer Nuclear Power to Neighborhoods
Meet EMMA, the Electron Model of Many Applications
A in the English countryside could be a harbinger of a safer, cleaner future of energy. Specifically, nuclear energy, but not the type that has wrought havoc in Japan and controversy throughout Europe and the U.S. It would be based on thorium, a radioactive element that is much more abundant, and much more safe, than traditional sources of nuclear power.
Some advocates believe small nuclear reactors powered by could wean the world off coal and natural gas, and do it more safely than traditional nuclear. Thorium is not only abundant, but more efficient than uranium or coal — one ton of the silver metal can produce as much energy as 200 tons of uranium, or 3.5 million tons of coal, as the calculates it.
The newspaper took a tour of a small particle accelerator that could be used to power future thorium reactors. Nicknamed EMMA — the Electron Model of Many Applications — the accelerator would be used to jump-start fissile nuclear reactions inside a small-scale thorium power plant.
Thorium reactors would not melt down, in part because they require an external input to produce fission. Thorium atoms would release energy when bombarded by high-energy neutrons, such as the type supplied in a particle accelerator.
Providing that stimulus is one obstacle to building small thorium reactors — but a new generation of accelerators like EMMA, and someday potentially even smaller, luggage-sized ones — could do the job.
EMMA is the first non- scaling, fixed-field, alternating-gradient (NS-FFAG) accelerator, qualities that make it easier to operate and maintain, more reliable and compact, more flexible and more efficient, according to . Other particle accelerators use alternating electric fields, which require special safety measures to guard against microwave exposure, for instance. EMMA’s alternating magnetic field gradients are a more efficient and cheaper way to accelerate particles to higher energies. (Brookhaven National Laboratory explains in more detail .)
EMMA operates at operates around 20 MeV, or 20 million electronvolts, a paltry amount for an atom accelerator. The Tevatron, for instance, accelerates particles to 1 tera-electron volts. The Large Hadron Collider is designed to speed them to 7 TeV. But thorium reactors would not need such high energies to initiate fusion.
British scientists are already working on a successor called PAMELA, the Particle Accelerator for Medical Applications, which will be used to treat cancer.
Click through to the for a full tour of EMMA, its sister apparatus ALICE (Accelerators and Lasers In Combined Experiments), and a description of British efforts to produce thorium power.
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Pocket Particle Accelerators Like This One Could Bring Safer Nuclear Power to Neighborhoods
Meet EMMA, the Electron Model of Many Applications
A in the English countryside could be a harbinger of a safer, cleaner future of energy. Specifically, nuclear energy, but not the type that has wrought havoc in Japan and controversy throughout Europe and the U.S. It would be based on thorium, a radioactive element that is much more abundant, and much more safe, than traditional sources of nuclear power.
Some advocates believe small nuclear reactors powered by could wean the world off coal and natural gas, and do it more safely than traditional nuclear. Thorium is not only abundant, but more efficient than uranium or coal — one ton of the silver metal can produce as much energy as 200 tons of uranium, or 3.5 million tons of coal, as the calculates it.
The newspaper took a tour of a small particle accelerator that could be used to power future thorium reactors. Nicknamed EMMA — the Electron Model of Many Applications — the accelerator would be used to jump-start fissile nuclear reactions inside a small-scale thorium power plant.
Thorium reactors would not melt down, in part because they require an external input to produce fission. Thorium atoms would release energy when bombarded by high-energy neutrons, such as the type supplied in a particle accelerator.
Providing that stimulus is one obstacle to building small thorium reactors — but a new generation of accelerators like EMMA, and someday potentially even smaller, luggage-sized ones — could do the job.
EMMA is the first non- scaling, fixed-field, alternating-gradient (NS-FFAG) accelerator, qualities that make it easier to operate and maintain, more reliable and compact, more flexible and more efficient, according to . Other particle accelerators use alternating electric fields, which require special safety measures to guard against microwave exposure, for instance. EMMA’s alternating magnetic field gradients are a more efficient and cheaper way to accelerate particles to higher energies. (Brookhaven National Laboratory explains in more detail .)
EMMA operates at operates around 20 MeV, or 20 million electronvolts, a paltry amount for an atom accelerator. The Tevatron, for instance, accelerates particles to 1 tera-electron volts. The Large Hadron Collider is designed to speed them to 7 TeV. But thorium reactors would not need such high energies to initiate fusion.
British scientists are already working on a successor called PAMELA, the Particle Accelerator for Medical Applications, which will be used to treat cancer.
Click through to the for a full tour of EMMA, its sister apparatus ALICE (Accelerators and Lasers In Combined Experiments), and a description of British efforts to produce thorium power.
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Chip-Sized Particle Accelerators Could Lead to Cancer-Fighting Ray Guns
OK, so it can’t reach the energies produced at the LHC or Tevatron, but this is still pretty impressive. Engineers at a micro-electro mechanical systems conference last week unveiled this tiny cyclotron device, which can speed argon ions down a 5-millimeter accelerator track.
The ions have 1.5 kiloelectron volts of energy and pick up another 30 electronvolts when they whiz around a 90-degree turn, as IEEE Spectrum explains. That is peanuts compared to the 3.5 teraelectron volts currently experienced at the LHC, but hey, this chip is several orders of magnitude smaller than that massive series of tubes.
Unlike most other accelerators, this device skips magnets and instead uses an electrical field to accelerate and steer its particles through a pair of electrodes.
The goal is a suitcase-sized accelerator capable of producing 1 MeV, which would make it powerful enough for a wide range of uses, according to the chip’s creators at Cornell University. Such a device could be used to make smaller scanning electron microscopes or portable ray guns to fight cancer, rather than installing particle accelerators inside hospitals, for instance: “Think of a scalpel with a proton beam coming out of it,” said Amit Lal, who worked with chip-builder Yue Shi and leads Cornell’s SonicMEMS Laboratory.
A few hurdles remain, including a more efficient way to grab ions from the 75-micrometer-wide beam. Lots of ions are lost in the transition, Shi said. But the device at least proves the concept that you don’t need humongous frozen magnets and cavernous spaces to speed up some particles.
DARPA is funding the work, which is ongoing at Cornell.
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LHC Reports Failure To Create Black Holes, a Setback For String Theory
At least not yet
Researchers working on the Compact Muon Solenoid team have been crunching numbers to test a form of string theory that calls for the creation and instant evaporation of miniature black holes. They report that the telltale signs of these black holes are disappointingly absent, however.
String theory is the most widely accepted attempt to unify the two major fields of physics, quantum mechanics and relativity. It holds that electrons and quarks are not objects, but one-dimensional strings whose oscillation gives them their observed qualities. It also says the universe has about a dozen dimensions, rather than the usual four (length, width, height and time).
In one version of string theory, if these dimensions exist, gravitons — hypothetical particles that transmit gravity — would leak into them, explaining why gravity is so much weaker than the other forces, as . It’s not really weaker, it just seems weaker, because some of its particles are in another dimension we can’t see. Happily, it takes a lot less energy to test this than it would to actually unify all the forces, and it just so happens it’s is in the energy range that the LHC, the world’s most powerful particle accelerator, is capable of testing.
If this is all true, particles that collided at energies beyond this graviton-leaking energy cutoff would get so close together that gravity would take over, and they would merge to form a tiny black hole. The black holes would instantly decay, so there would be no danger of Earth being swallowed whole, and the decay would be visible as jets of particles. But the researchers have so far seen no jets.
This doesn’t disprove string theory — it just proves that mini black holes can’t be produced at energies between 3.5 and 4.5 trillion electron volts. But they could still theoretically be produced at higher energies, so when the LHC fully fires up in 2013, string theorists will be holding their breath.
Meanwhile, the tests show the LHC is performing supremely well, so physicists aim to keep it running through 2012. This means they might be able to find the elusive Higgs boson sooner than expected.
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Particle Physicists Use Electrical Tape To Patch Tevatron
Faulty seal would have caused frustrating delays
Just before Labor Day, physicists working with Fermilab’s Tevatron wrapped up a planned four-week accelerator shutdown and were looking forward to getting back to work. But pressure started building in the Tevatron’s vacuum system, and experiments were halted while engineers isolated the problem. They found a faulty O-ring, which seals the vacuum between two superconducting magnets, according to an account on Fermilab Today.
The Tevatron is about four miles in circumference and involves about a thousand superconducting magnets, which accelerate protons and antiprotons to super-sized energies. The magnets are cooled with liquid helium so that they consume only one-third of the power they would normally require.
Replacing the O-ring seal would have required shutting down the Tevatron for at least 10 days, so the system could be slowly warmed up from -500 degrees F. Engineers would need several days to take apart the tube, replace the O-ring, check all the systems and cool the whole thing down again.
According to Fermilab Today, accelerator division mechanical support supervisor Scott McCormick wasn’t having any of it.
Luckily, he and a colleague had already conducted an experiment to test the strength of tape. During a scheduled shutdown four years ago, they removed a clamp from a seal and wrapped it in electrical tape. The resulting vacuum held for more than a year, so they knew it would buy them some time until they could make a permanent fix.
So, instead of pausing for a new O-ring, engineers used a roll of 5/8-inch black electrical tape to fix the problem. After a day and a half of calibrations and checks, the Tevatron was up and running again.
Sometimes the most complex problems are best solved with the simplest solutions.
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PopSci’s Guide To The 30 Coolest College Classes in the Country
Here's where you can learn to blow stuff up, scale 150-foot trees, make toys and catch lightning--all for college credit
Over the years, PopSci has pulled together annual lists of the coolest, funnest college labs, the places where we would like to have spent our youth tinkering, exploring, and learning. , we've collected the ultimate list of all the great labs we've ever covered.
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for our full illustrated list of the coolest college labs in the country.