February 13, 2009 | 8:28 am
Over the next days, symmetry will be reporting on the the AAAS 2009 meeting from Chicago. This year, there are lots of particle-physics-related results being presented at this largest general science conference in the United States. You can find all our coverage of this conference here or by choosing the AAAS 2009 category link in the right hand column.
David Harris
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February 12, 2009 | 3:21 pm
The American Institute of Physics Bulletin of Science Policy News is reporting that the $790 billion economic stimulus package approved by House and Senate conferees last night includes “significant funding increases” for science and technology, including $1.6 billion for the Department of Energy’s Office of Science, which funds particle physics.
Now the compromise bill goes back to the full House and Senate for final approval.
The AIP bulletin quotes the following from a statement issued by the office of House Speaker Nancy Pelosi:
“Investing in Scientific Research (More than $15 Billion)
“Provides $3 billion for the National Science Foundation, for basic research in fundamental science and engineering – which spurs discovery and innovation.“Provides $1.6 billion for the Department of Energy’s Office of Science, which funds research in such areas as climate science, biofuels, high-energy physics, nuclear physics and fusion energy sciences – areas crucial to our energy future.
“Provides $400 million for the Advanced Research Project Agency-Energy (ARPA-E) to support high-risk, high-payoff research into energy sources and energy efficiency in collaboration with industry.
“Provides $580 million for the National Institute of Standards and Technology, including the Technology Innovation Program and the Manufacturing Extension Partnership.
“Provides $8.5 billion for NIH, including expanding good jobs in biomedical research to study diseases such as Alzheimer’s, Parkinson’s, cancer, and heart disease.
“Provides $1 billion for NASA, including $400 million to put more scientists to work doing climate change research.
“Provides $1.5 billion for NIH to renovate university research facilities and help them compete for biomedical research grants.”
For the Office of Science, the compromise offers essentially the same level of funding as the House version of the bill–$2 billion overall, with $400 of it going to ARPA-E. The Senate version had designated $330 million for Office of Science, to be used for laboratory construction and infrastructure.
This is the first, broad-brush look at what the compromise bill holds for basic science; stay tuned for details.
Glennda Chui
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February 11, 2009 | 5:04 pm
Entertainment Tonight offers you a chance to see inside the world’s largest science experiment mentioned in the upcoming movie Angels and Demons.
The prime-time television show broadcasts Thursday and Friday, Feb. 12-13, from CERN, the European laboratory for particle physics research on the border of France and Switzerland.
Three rings are visible, the smaller shows the underground position of the PS, the middle ring is the SPS with a circumference of 7 km and the largest ring (27 km) is that of the former LEP accelerator with part of Lake Geneva in the background. Courtesy of Cern.
CERN serves as one of the settings for Angels and Demons, to be
released by Sony Pictures in May. The movie is based on the best-selling novel by Dan Brown, which explores the boundary between science and religion through an action-packed mystery.
Angels and Demons focuses on a plot to destroy the Vatican using a small amount of antimatter. In the book, that antimatter gets stolen from CERN and the heroine is a CERN scientist.
It is unclear how closely the movie will follow the book. In past interviews, Dan Brown has discussed the role CERN played in his book. CERN has posted a Q&A section on its Web site to clarify the distinctions between the events in the book and real-life science at CERN.
The movie stars Tom Hanks and is directed by Ron Howard.
You can see a trailer of the movie here.
We had a review of the book in the first issue of symmetry magazine, and included a scan of the title page, autographed by Dan Brown, in which he cautioned, “Remember, it’s fiction!!”
Tona Kunz
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February 10, 2009 | 2:34 pm
Swift's X-Ray Telescope (XRT) captured an apparent expanding halo around the flaring neutron star SGR J1550-5418. The halo formed as X-rays from the brightest flares scattered off of intervening dust clouds. Credit: NASA/Swift/Jules Halpern (Columbia Univ.)
In October 2008, the remnants of a collapsed star in the southern constellation Norma roared to life with a burst of gamma radiation. After a brief hiatus it reawakened January 22, sending out blasts of gamma rays powerful enough to fuel a lingering X-ray afterglow. The star was recently renamed SGR 1550-5418 for its new status as the sixth known soft gamma-ray repeater, a source of celestial fireworks thought to be powered by the extreme magnetic field of an unusual neutron star.
SGR 1550-5418′s gamma flares traveled across 30,000 light years before they were captured by the Gamma Burst Monitor onboard the Fermi Gamma-ray Space Telescope, a joint collaboration of NASA, DOE, and international partners, in orbit above the Earth. The Swift satellite, also a NASA project, captured the X-rays that followed.
“At times, this remarkable object has erupted with more than a hundred flares in as little as 20 minutes,” says Loredana Vetere, who is coordinating the Swift observations at Pennsylvania State University. “The most intense flares emitted more total energy than the sun does in 20 years.”
Astronomers theorize that such immense energy releases slow the star’s rotation from many per second to one turn in 10 seconds, in as little as 10,000 years. With a period of 2.07 seconds, the new SGR has the fastest known rotation of its class.
SGR 1550-5418 is the newest in a class of astronomical objects prone to irregular outbursts of gamma radiation-the most energetic light in the electromagnetic spectrum. Soft gamma-ray repeaters emit unpredictable, single or repeating bursts at the less-powerful, “soft” end of the gamma range. These outbursts pack enough punch to ionize parts of the Earth’s upper atmosphere from 50,000 light years away. SGR 1550-5418′s latest gamma activity was followed by a longer-lasting emission of X-ray light that shone in halos around its source as it scattered though interstellar dust.
The intense radiation is thought to result from the violent starquakes of a magnetar, a neutron star with a magnetic field so powerful it causes the star’s outer crust to buckle and crack, releasing huge storms of energy in the form of gamma rays. That in turn heats the surrounding matter, which releases the pent-up energy in an X-ray afterglow.
“There is a bright flash of gamma rays that lasts typically less than a second,” says Columbia University professor Jules Halpern, who used data from Swift to trace the new SGR’s X-ray halos. “That will heat the surface and the magnetosphere of the star, which will emit in X-rays for several hours or days-it’s a combination of the heat from the surface and probably a fireball of even hotter electrons in the magnetosphere of the neutron star.”
SGR 1550-5418 was first spotted in 2007 and cataloged as another class of neutron star-an anomalous X-ray pulsar, or AXP. “There are two classes of neutron stars that have very strong magnetic fields, SGRs and AXPs,” Halpern says, “Normally they’re distinct; only the SGRs have the most powerful outbursts.” SGR 1550-5418 is now elevated to the status of an SGR because of its energetic outbursts. Its change in behavior could theoretically be part of the evolution of the star, he notes, “but the interval between bursts could be decades.” It’s been only 30 years since the first SGR was discovered, so only time will tell.
Shawne Workman
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February 9, 2009 | 3:19 pm
The following text is from a CERN press release issued today. This is a followup from Friday’s release.
Geneva, 9 February 2009. CERN management today confirmed the restart schedule for the Large Hadron Collider (LHC) resulting from the recommendations from last week’s Chamonix workshop. The new schedule foresees first beams in the LHC at the end of September this year, with collisions following in late October. A short technical stop has also been foreseen over the Christmas period. The LHC will then run through to autumn next year, ensuring that the experiments have adequate data to carry out their first new physics analyses and have results to announce in 2010. The new schedule also permits the possible collisions of lead ions in 2010.
In Chamonix there was consensus among all the technical specialists that the new schedule is tight but realistic.
“The schedule we have now is without a doubt the best for the LHC and for the physicists waiting for data,” said CERN Director General Rolf Heuer. “It is cautious, ensuring that all the necessary work is done on the LHC before we start-up, yet it allows physics research to begin this year.”
This new schedule represents a delay of six weeks with respect to the previous schedule, which foresaw the LHC “cold at the beginning of July”. The cause of this delay is due to several factors such as implementation of a new enhanced protection system for the busbar and magnet splices; installation of new pressure-relief valves to reduce the collateral damage in case of a repeat incident; application of more stringent safety constraints; and scheduling constraints associated with helium transfer and storage.
The enhanced protection system measures the electrical resistance in the cable joints (splices) and is much more sensitive than the system existing on 19 September.
The new pressure relief system has been designed in two phases. The first phase involves installation of relief valves on existing vacuum ports in the whole ring. Calculations have shown that in an incident similar to that of 19 September, the collateral damage would be minor with this first phase. The second phase involves adding additional relief valves on all the dipole magnets and would guarantee minor collateral damage (to the interconnects and super-insulation) in all worst cases over the life of the LHC.
The management has decided for 2009 to install the additional relief valves on four of the LHC’s eight sectors, at the same time as repairs in the sector damaged last September and other consolidation work already foreseen. The dipoles in the remaining four sectors will be equipped in 2010.
David Harris
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February 6, 2009 | 1:58 pm
Call it the Energizer Bunny of particle physics: The GammeV collaboration reins in costs, works fast and just keeps going.
The 10-person Fermilab collaboration formed in April 2007 to look for candidates for dark matter and dark energy. Although several members work on other experiments as well, they were drawn to GammeV’s unique attributes. Its small size allows for large individual roles in building and analysis, plus a chance to search for exotic particles while exploring areas of physics often overlooked by larger collaborations.
By scrounging parts, including an Accelerator Division laser, a Tevatron dipole magnet, and QuarkNet circuit boards, from old experiments, the collaboration kept to a budget of $30,000. The collaboration took less than a year to propose, build and publish results from its first experiment setting new exclusion limits on axion-like particles in the milli-eV mass range.
The collaboration tweaked its equipment and produced in less than a year another set of results, this time on the chameleon particle.
What’s a chameleon particle? A special Results of the Week article in today’s issue of Fermilab Today explains:
In the chameleon dark-energy model, the observed acceleration of the universe is caused by a light, spin-zero particle that evades other experiments. This evasion is due to the fact that the properties of the hypothetical chameleon particle—namely its mass—depend upon the environment, hence the chameleon moniker. GammeV collaborators exploit this effect to trap these chameleon particles in a jar-like vacuum chamber.
Collaborators generate chameleon particles by interacting polarized laser light with a magnetic field. Some of the photons oscillate into chameleon particles, which pass through the jar but bounce off of the walls of the vacuum chamber–including the optical windows at each end. When the laser is turned off, the jar empties as the chameleons reconvert to detectable photons. This afterglow is a telltale signature of the chameleon particle.
While they didn’t find a signal in this round of work, the results did put constraints on some of the properties of the evasive particle, including its mass and its coupling to photons.
Next on the agenda is a possible proposal to upgrade the chameleon experiment during the next year. Once again the experiment would carry a discounted price tag by taking advantage of the old equipment with a few internal modifications, mainly to the vacuum pump system, and another recycled magnet.
The first chameleon search looked at exclusion plots on “fringe or extreme” models of chameleon particles as dark-energy candidates. The second experiment is expected to probe exclusion plots for a much wider range of models.
How will the collaboration follow that up? Members hope to eventually upgrade their original axion study, but that would require a much larger budget and three to five years of work.
This story first appeared in Fermilab Today on February 6, 2009.
Tona Kunz
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February 6, 2009 | 1:36 pm
A press release from CERN today announced that the laboratory hopes to run the LHC with 5 TeV beams with collisions in late 2009, producing data suitable for physics analysis. Eventually the LHC will run with 7 TeV beams.
This recommendation comes after a week-long meeting in Chamonix, France, where the details of the LHC repairs were also discussed in detail. A CERN management meeting on Monday will determine whether this recommendation is accepted and the start-up schedule does indeed include physics operations in late 2009. UPDATE: CERN management accepted the recommendation. Details here.
In CERN’s regular weekly LHC update, they said that as part of the campaign to avoid another incident like the one that shut down the LHC in September ’08, a new protection system is being installed in the LHC to detect tiny electrical resistances on the superconducting busbars between magnets. Materials and electronics necessary for the system are being ordered and manufactured, with installation of some components already underway. More details here.
Full text of the press release:
CERN to set goals for first LHC physics
Geneva, 6 February 2009. At the conclusion of a workshop held in Chamonix this week, recommendations have been made to the CERN [1] management for the restart schedule of the Large Hadron Collider (LHC). If accepted in a management meeting on Monday, these recommendations will ensure that the LHC starts to produce physics data in late 2009, running through the winter and on to autumn 2010 at an energy of 5 TeV per beam and ensuring sufficient data for the experiments to produce their first new physics results.
“These recommendations represent the best way forward for the LHC and for the field of particle physics in general,” said Steve Myers, CERN’s Director for Accelerators and Chair of the Chamonix workshop.
Among the topics discussed in Chamonix was the underlying cause of the incident that brought the LHC to a standstill on 19 September last year. The incident was traced to a faulty electrical connection between segments of the LHC’s superconducting cable. Since the incident, enormous progress has been made in developing techniques to detect any small anomaly. These will be used in order to get a complete picture of the resistance in the splices of all magnets installed in the machine. This will allow improved early warning of any additional suspicious splices during operation. The early warning systems will be in place and fully tested before restarting the LHC.
Following the incident, a further two suspect connections have been identified. One of these has now been investigated, revealing that the splice between cables had not been correctly carried out. As a result the magnet containing the second will also be removed from the tunnel for repair. Since resistance tests can only be conducted in cold magnets, three of the LHC’s eight sectors remain to be tested: sector 3-4 where the original incident occurred and the sectors on either side. Within sector 3-4, the 53 magnets that are being replaced in the tunnel will all be tested before cool down, and the sectors either side will be cooled down early enough to intervene if necessary with no impact on the schedule. This leaves around 100 dipole magnets that cannot be tested until September, and a correspondingly small chance that repairs may run into currently scheduled running time.
“CERN’s priority for 2009 is to get collision data for the experiments, but with caution as the guiding principle,” said Myers. “The recommendations made to the CERN management are cautious, while achieving the goal of running this year.”
“A lot of hard work went into the Chamonix workshop,” said CERN Director General Rolf Heuer, “giving my management team all we need to make the right decision on LHC restart when we next meet on Monday.”
The restart schedule for the LHC will be announced following the CERN Directorate meeting on Monday 9 February.
[1] CERN, the European Organization for Nuclear Research, is the world’s leading laboratory for particle physics. It has its headquarters in Geneva. At present, its Member States are Austria, Belgium, Bulgaria, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Italy, Netherlands, Norway, Poland, Portugal, Slovakia, Spain, Sweden, Switzerland and the United Kingdom. India, Israel, Japan, the Russian Federation, the United States of America, Turkey, the European Commission and UNESCO have Observer status.
With additional reporting from Katie Yurkewicz.
David Harris
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February 6, 2009 | 12:20 pm
Many scientists were extremely excited by the stimulus bill that passed the US House of Representatives because it included significant funding for science, which in many fields is currently operating at FY07 levels due to continuing resolutions.
As the stimulus package, which passed the House at a cost of $885 billion dollars, moved to the Senate, it ballooned to $937 billion.
A group of senators is now arguing that the total cost should be closer to $800 billion and have presented a document for discussion that shows where the cuts will be made. (See the full document here.) Many scientists are alarmed that the proposed cuts include the entire contributions to NSF, DOE’s Office of Science, NASA exploration, along with substantial cuts to other science programs. (Full disclosure: Funding for symmetry magazine comes via the DOE Office of Science through the national laboratories.)
The American Physical Society president, Cherry Murray, wrote a letter to all APS members asking for them to write to their congressional representatives to encourage funding for science in the stimulus bill. Many science listservs have also been sending calls to action for funding, and science enthusiasts on social networking sites like facebook and the microblogging service twitter have been sending alarms to their colleagues and friends.
Meanwhile, President Obama spoke at DOE Headquarters in Washington, DC, yesterday to push for adoption of the stimulus package and he also mentioned a few specific actions he is taking with regard to DOE, including a memorandum instructing DOE to tighten efficiency standards for some household appliances. More details of his speech are here. View .wmv video of the speech here.
A Senate vote on the bill could come as early as today, or possibly Sunday.
David Harris
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February 3, 2009 | 8:31 pm
The cosmic ray detector aboard the PAMELA spacecraft. Illustration: Courtesy of the PAMELA Collaboration.
Last August, a stir went through the physics community when a presenter at the International Conference on High Energy Physics in Philadelphia, Pennsylvania, showed some data from the PAMELA satellite. The data indicated a surprising excess of positrons and anti-protons in the cosmic rays raining down on Earth. Various commenters and scientists speculated that this could be a signal of dark matter particles annihilating.
The incident became more intriguing when other scientists used photos, taken during the presentation, of the slides to extract the data and then present analysis of that data in other scientific papers. (See “Paparazzi or preprints?“) Unresolved at the time was whether these signals really were evidence for dark matter.
A new paper published in Physical Review Letters this week, presents data from 500 days of data collection by PAMELA, and an analysis of the ~1000 anti-protons observed, including ~100 very high energy anti-protons. The collaboration concludes that the data is not likely to be a sign of dark matter annihilation, but places some very stringent constraints on how much of a signal of dark matter could be present in the cosmic ray flux.
An excellent (but somewhat technical in places) commentary and explanation of these results appears in Physics and is well worth digging in to if you are interested in the topic, but aren’t sure if you are up to reading the full paper.
Update: Sean Carroll at Cosmic Variance has a bunch more very useful context and information on this work.
David Harris
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volume 08 | issue 03 | october 11
On the cover:
As symmetry celebrates its 50th issue, big changes are afoot at Fermilab.
The lab’s Tevatron Collider, once the most powerful particle collider in
the world, is shutting down, and a new project is on the horizon: Project X.
This proposed $1.8 billion accelerator complex would keep Fermilab at
the forefront of high-energy physics, this time at the Intensity Frontier—a realm
in which scientists bring incredible numbers of particles into collision to
search for extremely rare processes with a big physics impact. It’s exactly
the kind of place where discoveries may lie. See “Solving for X”.
Photo illustrations: Reidar Hahn, Fermilab and Sandbox Studio
© 2011 symmetry. A joint Fermilab/SLAC publication. PO Box 500 MS206, Batavia, IL 60510, USA
