Heroes of the Tevatron: electrical tape and ingenuity

September 29, 2010 | 10:08 am

Tevatron repair team: (from left to right) James Williams, Bill Dymond, Scott McCormick, Sali Sylejmani and Dan Lambert

This story first appeared in Fermilab Today on September 29, 2010.

On Friday afternoon before Labor Day weekend, pressure in the Tevatron’s cryostat vacuum system suddenly started rising. The Accelerator Division mechanical support team tracked the issue to a faulty rubber O-ring, the part that seals the vacuum between two superconducting magnets.

Placing a new O-ring around the beamline would have required at least a 10-day shutdown to warm up the Tevatron from about minus 500°F, to disassemble the tube, to replace the ring, to complete a full mechanical and vacuum certification of the entire section and to cool it back down. This would have been frustrating for the Tevatron’s scientists, who had just ended a scheduled four-week shutdown and were anxious to get back to their experiments.

Accelerator Division mechanical support supervisor Scott McCormick wouldn’t accept such a solution.

“This big machine is four miles in circumference, with a thousand-some superconducting magnets, and one piece of rubber is gonna stop us?” he said. “I don’t think so. Not if we can help it.”

Four years ago, McCormick and senior operations specialist Dave Augustine had done an experiment testing this exact scenario. During a scheduled shutdown, they removed the clamp from a similar juncture and wrapped the interface in electrical tape. The resulting vacuum held for more than a year. In a real emergency, this would buy them more than enough time until a permanent repair could be made.

So, after much discussion and safety optimization, they decided to try it on the actual leak during the holiday weekend. Four leak detectors, six vacuum pumps, five technicians, one roll of 5/8-inch black electrical tape and a day and a half later, the Tevatron was up and running without a hitch.

“Whenever you are working with a vacuum, there’s always an element of risk to the machine,” said James Williams, AD senior technician who helped with the fix.

A faulty rubber O-ring threatened to take the Tevatron out of operation for more than a week.

AD run coordinator Cons Gattuso said, “Having the repair only take two days is a big relief when it comes to planning on the run coordination side of things.”

Although mechanical failures are much rarer now than they used to be, McCormick said that O-ring failure is likely to occur more often as the Tevatron ages. But even with this solution in hand, the team isn’t basking in their success.

“This is our job; it never ends just because we found another solution,” McCormick said. “There’s always a better, faster, safer way to get us back online.”

– Sara Reardon

Symmetry Intern

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Cast your vote for top Particle Physics Photowalk photograph

September 27, 2010 | 11:24 am

On August 7, more than 200 photographers had the rare opportunity to go behind the scenes at five laboratories in Asia, Europe and North America as part of the first Global Particle Physics Photowalk. Thousands of photographs were submitted to the laboratories for local and global competitions. The laboratories have made their choices, each nominating three photographs for global competition. Now it’s your turn – starting today, you may vote for up to three of your favorite photographs as part of the “people’s choice” global photowalk competition.

At the 2010 Particle Physics Photowalk, more than 200 photographers had the rare opportunity to experience state-of-the-art accelerators and detectors in all of their complexity and beauty.

On the day of the big event, CERN in Geneva, Switzerland; DESY in Hamburg, Germany; Fermilab in Batavia, Illinois; KEK in Tsukuba, Japan; and TRIUMF in Vancouver, Canada, all opened their doors to photographers armed with cameras, lenses and hungry, hungry eyes. Each laboratory conducted its own local competition with panels of judges or tallying votes from laboratory staff. The winners are a diverse group, ranging from a high school student in Canada to a lead technician in a manufacturing company in Germany.

As a nature photographer and retired landscape designer, Chuck Peterson, a finalist who attended the photowalk at Fermilab, has a creative eye for juxtaposing nature with man-made objects. When presented with the rare opportunity to photograph the inner sanctum of a particle physics laboratory, he jumped right on board.

“Fermilab’s unique combination of natural areas and scientific research create very interesting juxtapositions in photography,” said Peterson, a resident of St. Charles, Illinois. “It is a fun site to photograph.”

Ali Lambert, a junior in high school from Vancouver, Canada, won the local competition at TRIUMF. She had never entered a photo contest before and spent last summer working as a receptionist to save up for her camera, now her most prized possession. “I really enjoy photographing the simple things that people usually take for granted,” she said.

The Particle Physics Photowalk is organized by the InterAction Collaboration, whose members represent particle physics laboratories in Asia, North America and Europe.

“The reason we decided to do the photowalk was to invite people in who might have a different way of looking at things, at our laboratory, than the people who work here every day. And the results show that we were right – we have some wonderful photographs taken by participants,” said James Gillies, head of communication at CERN.

In the spirit of friendly competition, the laboratories have organized two global competitions. In addition to the people’s choice winner, a panel of international judges will select a second global winner. Both winners will be announced in October. The winning photographs will be featured in the December issues of the particle physics publications the CERN Courier and symmetry. All five participating laboratories will also feature the global winners and their local photowalk selections in temporary exhibits in 2011.

View the 15 finalists and cast your vote at Interactions.org.

Follow particlenews or the hashtag #pppw on Twitter for the latest updates from the Interactions.org.

Elizabeth Clements

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So long and thanks for all the physics: The Hitchhiker’s Guide

September 24, 2010 | 10:00 am

Ilten used Feynman diagrams to draw the alien from the cover of the U.S. release of The Hitchhiker's Guide to the Galaxy.

Of all of the documents uploaded to the arXiv – a virtual library of scientific publications – it is possible that only one is adorned with a smiling alien made of Feynman diagrams and the words “DON’T PANIC.”

You might need an Infinite Improbability Drive to verify that claim, though. Over the course of more than 19 years, users have uploaded more than 627,000 publications to the database.

The document in question is “The Hitchhiker’s Guide to First Year Physics Labs at UCD,” a collection of handouts PhD student Philip Ilten wrote between 2009 and 2010 for a class of freshmen he taught at University College Dublin.

Ilten arranged his handouts into a book during downtime at a theory school on QCD phenomenology and shared them with the world on Sept. 9. “I’m a die-hard believer of open-source,” he wrote in an e-mail. “I really believe that for science to make progress, we need to share absolutely everything.”

It’s not that he thinks his explanations are perfect. In the introduction to the book, he warns, “Despite my best effort, I am certain this book still contains spelling mistakes, grammar mistakes, and worst of all, physics mistakes.”

But the book is a living, crowd-sourced effort. A couple of people have already contacted him to offer their input, and he has made corrections.

A glance through the Physics Education section of the arXiv reveals that comprehensive guides like this are rare in the library. Rarer still might be the guide’s approachable language and conversational tone.

Ilten defined terms and used metaphors to present the background his students needed – with a dash of personality.

One chapter explains the “haze of misinformation” surrounding beta radiation. It opens with the sentence: “Take a scrawny nerd, add a dash of a scientific experiment, and bombard the mixture with a large amount of radiation; this is the recipe for a superhero.”

A footnote adds, “The two most famous being Spiderman and the Incredible Hulk, and possibly Captain America, although his origins are somewhat up to debate due to comic book censorship.”

Ilten uses asides like these to carry his students through more treacherous territory, a trick he picked up in class.

“The day I was teaching my students about superconductivity, I saw panic in many of their eyes (probably had to do with the terrible explanation I was giving),” he wrote, “and so whenever I wrote a nasty formula on the board, my motto would be, ‘Don’t panic.’”

He wrote his first handout when a student asked him a question about Gaussian uncertainty.

“I knew the technical answer,” he wrote,” but I couldn’t express it in a way that would be understandable to a first-year physics student, so I told the student I would write up the answer and have it for the next lab.”

He continued to get requests, so he continued to create the explanations, with unexpected results.

“I think the handouts convinced many of my students that I was very serious about these labs,” he wrote, “and so they put in extra effort to understand the material.”

Of course, the only answer they really needed to know was 42.

Kathryn Grim

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Fermilab considers extending Tevatron run by three years

September 21, 2010 | 4:21 pm

Fermilab's Tevatron is the world's largest proton-antiproton collider.

In today’s edition of Fermilab Today, Fermilab Director Pier Oddone announced that the laboratory would extend the run of its flagship particle accelerator by three years if the laboratory could secure additional resources and if Fermilab could minimize the effect that continuing to run the Tevatron would have on other experiments.

The Tevatron, the world’s highest-energy proton-antiproton collider, is scheduled to close in September 2011. In August, an international advisory committee recommended Fermilab extend the Tevatron’s run. Oddone wrote in today’s column that finding supplemental funding would be “absolutely essential for Tevatron operation beyond FY11.”

Oddone has requested the Department of Energy grant about $35 million in additional funds to the U.S. particle physics community for each year of the proposed extended run. If DOE could help pay for the extra physics research staff required in the U.S. high-energy physics program, Fermilab would contribute by diverting funds from two of its other large projects, NOvA and Mu2e, during FY12-14.

“Securing additional resources in the present funding climate is a tall order, and it will take some time,” Oddone wrote. “It is also important that we at Fermilab take responsibility for providing some of the needed resources out of our own hide.”

DOE could say no to this plan at any time, Oddone wrote. A “yes” would not be final until the President signed the Energy and Water Appropriations bill in 2011.

“Although this may appear like a high level of uncertainty, it really is no higher than the usual uncertainty for any proposed new activity,” Oddone wrote. “In the meantime we have a serious challenge to continue planning along both our current path and a new path with extended Tevatron running.”

Kathryn Grim

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LHC experiment observes potentially new and interesting effect

September 21, 2010 | 10:59 am

This statement was issued on September 21, 2010, by CERN. The original announcement is available here.

Image of a 7 TeV proton-proton collision in CMS producing more than 100 charged particles.

After almost six months of operation, experiments at the LHC are starting to see signs of potentially new and interesting effects. In results announced by the CMS collaboration today, correlations have been observed between particles produced in 7 TeV proton-proton collisions.

In some of the LHC’s proton-proton collisions, a hundred or more particles can be produced. The CMS collaboration has studied such collisions by measuring angular correlations between the particles as they fly away from the point of impact, and this has revealed that some of the particles are intimately linked in a way not seen before in proton collisions.

The effect is subtle and many detailed crosschecks and studies have been performed to ensure that it is real. It bears some similarity to effects seen in the collisions of nuclei at the RHIC facility located at the US Brookhaven National Laboratory, which have been interpreted as being possibly due to the creation of hot dense matter formed in the collisions. Nevertheless, the CMS collaboration has stressed that there are several potential explanations to be considered and the collaboration’s presentation to the physics community at CERN today focussed on the experimental evidence in the interest of fostering a broader discussion on the subject.

“Now we need more data to analyse fully what’s going on, and to take our first steps into the vast landscape of new physics we hope the LHC will open up,” said CMS Spokesperson Guido Tonelli.

Proton running at the LHC is scheduled to continue until the end of October, during which time CMS will accumulate much more data to analyse. For the remainder of 2010 running, the LHC will collide lead nuclei.

Another CERN experiment that will be following developments with great interest is ALICE, whose detector is optimised to study collisions of nuclei. Like the experiments at RHIC, ALICE aims to study matter in the hot dense state that would have existed just tiny fractions of a second after the Big Bang in a bid to understand how such matter evolved into the ordinary nuclear matter that makes up the Universe today. The observation of proton-proton collisions producing large numbers of particles bodes well for this new phase of LHC running.

Having presented results on known physics at the conferences earlier in the summer, LHC experiments are now probing new ground.

Elizabeth Clements

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Fermilab constructs pioneering accelerator test facility

September 21, 2010 | 9:30 am

Construction workers gather for a safety briefing in the Fermilab test accelerator facility.

This release was issued on September 21, 2010, by Fermi National Accelerator Laboratory.

Batavia, Ill.—Officials at the Department of Energy’s Fermi National Accelerator Laboratory announced today that the laboratory has started phase II of the construction of a pioneering facility to advance a technology that will be critical to the next generation of particle accelerators.

The new facility, which will occupy three buildings and host a 460-foot-long test accelerator, will be the first of its kind in the United States.

Fermilab is using $52.7 million in funding from the American Recovery and Reinvestment Act to advance its Superconducting Radio-Frequency R&D program, which includes the construction of the SRF Accelerator Test Facility. Phase I of the construction began in March 2010 with the $2.8 million expansion of an existing building. For phase II, the laboratory has awarded a $4.2 million contract for the construction of two new buildings. Additional ARRA funds will go toward equipment and infrastructure needed for the building’s operation. Fermilab will use the facility to test superconducting radio-frequency components and validate the manufacturing capability of vendors from U.S. industry.

“Our future is going to involve accelerators that use superconducting radio-frequency technology,” said Jay Theilacker of Fermilab’s Accelerator Division. “Building this new SRF test facility is an important step forward.”

The structures operate inside containers known as cryomodules, which chill the cavities to -456 degrees Fahrenheit, a temperature where they can conduct electric current without electrical resistance—hence the term “superconducting.”

Fermilab plans to use the facility to test cryomodules designed for two proposed future particle accelerators: Project X, which would be built at Fermilab, and the International Linear Collider, which could become the world’s next high-energy collider, designed and built through an international effort. The laboratory’s current flagship accelerator, the Tevatron, is scheduled to retire after 2011. It does not use SRF technology.

Michigan-based Barton Malow Inc. will do the civil construction for the SRF test facility, which will consist of three interconnected structures. One will house the SRF test accelerator; the second will accommodate the testing area for cryomodules, which are the building blocks of an SRF accelerator; and the third will house the equipment for a powerful new refrigerator that will cool the cryomodules in the test accelerator and the test area.

Scientists will also use the particle beam generated by the test accelerator to develop and design better instruments and advanced accelerator technology, which have applications in many fields, including medicine and industry.

Since March, Barton Malow subcontractors have hired about 200 Chicago-area tradespeople to work on the test facility expansion.

“There have been about 20 people here per week, all local,” said Barton Malow Project Manager Keith Wiederhold.

He expects that building the two new structures will require a similar number of workers. The company plans to finish the project by the fall of 2011.

Press Release

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LHC experiments push limits in new publications

September 20, 2010 | 10:00 am

The LHCb collaboration at CERN tightened constraints on previously imprecise theories in b-flavor production in its first paper using data from 7 TeV collisions.

The results mark the collaboration’s first inquiry into one of the main subjects it was built to study: rare decays that result in composite particles that contain bottom quarks or their antiparticles.

Physicists measured how often these particles, called b-flavored hadrons, appeared in the aftermath of collisions in the LHCb detector. The results fit within predictions from theory, said LHCb physicist Sheldon Stone, who worked on the paper. But those predictions were not well defined.

“The theoretical predictions had very large errors, 50 percent,” Stone said. “This will serve to constrain the theories. It’s a number we need to know to estimate what we can do in the future.”

The collaboration members hope eventually to see evidence of new physics, which means finding results that don’t match expectations. “But this result tells us we have enough b-quarks to do our job,” Stone said.

They should have enough information to sift through as well. When they wrote this result, they had collected 15 inverse nanobarns of collision data.

“We already have 3,500 for the next one,” Stone said.

The about 700 members of the LHCb collaboration, a small group compared to other experiments at the LHC, hope to build up to a rate of publishing 50 to 100 papers per year, he said.

The study built upon earlier measurements taken at lower energies in the Large Electron-Positron Collider and Fermilab’s Tevatron.

Another collaboration at the Large Hadron Collider, ATLAS, also recently published results that stretched physicists’ knowledge of particle interactions up to the 7 TeV range. Results from the ATLAS detector expanded the range over which physicists could rule out the existence quarks in an excited state. The discovery of excited quarks would have raised suspicions that quarks, the smallest units of matter detected, might be composed of even smaller particles.

The collaboration first announced the results at the International Conference on High Energy Physics in July.

Edit: The LHCb paper is also available here.

Kathryn Grim

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Be a researcher for a night

September 16, 2010 | 8:27 am

Next Friday, September 24, CERN’s scientific community – already 10,000 strong – will expand even more. As part of European Researchers’ Night, the European laboratory for particle physics will give people from all over the world a peek into the lives of scientists on the Large Hadron Collider during an eight-hour-long webcast. More than 100 lucky students from CERN’s local community will sit side by side with scientists and operators in the control rooms for the LHC experiments.

The Globe Show webcast, which will air from 11 a.m. to 7 p.m. Eastern time, is presented in collaboration with the Italian science assocation Frascati Scienza, the Erasmus Medical Centre in The Netherlands, and the Joint European Torus fusion experiment. The webcast will air live from all four locations, bringing together scientists on the front lines of particle physics, astrophysics, medicine and energy research. Audiences participating from the four locations will be able to ask questions of physicists at CERN, scientists from the Ice Cube experiment in Antarctica, ESA astronaut Roberto Vittori, and Nobel laureate Sam Ting at the Kennedy Space Center in Florida, where he is preparing the AMS particle detector for its journey to the International Space Station. The webcast will be presented in multiple languages, including English, from 11 a.m. – 4 p.m. Eastern time, and primarily in English from 4 – 7 p.m. Eastern.

On September 24, watch the webcast at http://webcast.cern.ch.

For more information about European Researchers’ Night, read the article in the CERN Bulletin or today’s press release.

Katie Yurkewicz

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DUSEL planning on track

September 13, 2010 | 10:01 am

A graphic summarizing the various kinds of scientific experiments that could take place in the proposed Deep Underground Science and Engineering Laboratory.

This story first appeared in Fermilab Today on September 3, 2010.

At the first meeting of potential DUSEL users, participants and funding agencies expressed satisfaction with the progress of the design for the next proposed national laboratory and its experiments.

“Where the proposal is today is very satisfactory, and the trajectory is good,” said Joseph Dehmer, director of the physics division at NSF.

If approved, construction and experiment installation could begin in 2014 and continue for seven years. A few experiments still in the R&D phase would be installed one to three years later.

The breadth of the experiments and their often one-of-a-kind nature makes DUSEL stand out, attendees said. Not only will the physics experiments put the U.S. at the head of neutrino and dark matter research, but the depth and large caverns the experiments require will allow for deep underground biology, geology and engineering research at unprecedented scales.

The suite of experiments will not be finalized for at least another year. The DUSEL Program Advisory Committee said a loosely-defined suite of experiments is specific enough to finish the facility’s design but leaves flexibility for later selecting individual experiments and their designs.

So far NSF has received 25 research proposals. In general, the non-physics programs will study carbon sequestering, tunnel engineering, deep life forms and the effects of water removal and construction on seismic activity and life forms.

The proposed physics experiments break into five broad research categories: supernovae, dark matter, proton decay, neutrino mass hierarchy and neutrinoless double beta decay.

Current construction plans would allow for two simultaneous installations at the surface level. Vertical experiments such as carbon sequestering would exist from the zero to 1,700-foot level. The 4,850-foot level cavern could hold four to five physics experiments while the 7,400-foot level cavern could accommodate two physics experiments. All levels also could contain earth science experiments.

In December the preliminary design report with a revised schedule and cost will be given to NSF. DOE and NSF will receive an updated report on DUSEL science in spring 2011, and the funding agencies are expected to decide in August 2011 whether to proceed.

“We are looking forward to the next steps on this,” said Heidi Schellman, DUSEL PAC member. “So, let’s go.”

Tona Kunz

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Using art to understand particle physics

September 10, 2010 | 12:00 pm

“Eyes” of Particle Physicists by Teppei Katori

Looking around at the Hard Science art exhibit in Chicago, you might be persuaded that someone with a canvas and paint can translate physics laws as effectively as someone with a calculator and a pencil.

Earlier this summer, Chicago’s Chuck Przybyl challenged a handful of artists to interpret the principles and practices of particle physics in their favored media.  The result was Hard Science, which recently concluded at the Chicago Art Department.

“These ideas are cool – time, space, symmetry,” says Teppei Katori, a post-doctoral researcher from  MIT who works with Fermilab.  “The art doesn’t have to be correct, just science-inspired.”

Artist Edyta Stepien, who curated the exhibit with Przybyl, hoped to create something that would translate the highly conceptual realm of particle physics in a visually accessible way. She used pencil and ink to depict her take on the Higgs field and particle, which, she says, are fascinating in that so much of physics theory hangs on them though they haven’t been discovered.

The idea for the exhibit grew out of conversations between the artists and Katori.

“I didn’t understand the title of Teppei’s thesis.  I couldn’t get through just listening to one sentence,” Przybyl says.  “It was a reminder of how much knowledge is out there and how specialized these fields are.  That inspired me.”

Teppei Katori

Katori gave Przybyl, artist Mark Salach and Stepien a tour of the Fermilab, a
high-energy particle physics laboratory outside of Chicago.  During several extended gatherings, he also shared his knowledge of the particle world, including the Higgs boson search and the years of research that go into making a single measurement of a particle property.

Przybyl then invited artists to create works related to science concepts.  They responded with pieces that address various subjects, like the machinery of particle detection and the act of data-taking.

“I quickly found that I could kind of understand what scientists were talking about, but there was always the one part that I just couldn’t get,” says Nat Soti, artist and Chicago Art Department co-founder. “That was the challenge – trying to understand it in order to make art about it.”

Once they did come to grips with the physics, the artists had the additional challenge of recasting those science concepts for viewers.

During the exhibit opening, Todd Frugia performed his piece Despite My Limitations.  In it, he sat for four hours wearing noise-cancelling head phones while observing the gallery and its occupants in an attempt to view everything as a collection of particles.  Attendees were invited to sit with him, don headphones, and also try to see the room, or Frugia himself, as made of the tiniest bits of matter.

“Scientists are in fact telling us that particles are what the world is made of,” he says.  “What does it mean for someone to try to see it at this base level?”

The comedic potential of his performance is not lost on him: he fully expected some attendees – themselves particle collections – to get a chuckle out of his performance.

Katori, a scientist by profession, also contributed several art works to the exhibit.  In “Eyes” of Particle Physicists, photomultiplier tubes – instruments that detect minuscule amounts of light and so “see” what the naked eye can’t – are shown with clay veins and nerves crawling out their backs.

“This device is an extension of your body,” Katori says.  “It’s like an eyeball for the physicist.”

Though several artists expressed trepidation at what scientists might think about their takes on physics, Katori says the exhibit isn’t about getting it scientifically right.

“My hope is that, as people spend time with the pieces, the art will prompt them to investigate the science,” Przybyl says.

Visit the Hard Science site and its Flickr site.

– Leah Hesla

Symmetry Intern

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