LHC now cooled to superconducting temperatures

October 16, 2009 | 10:29 am

This chart shows just one of the eight LHC sectors cooled to operating temperatures below 1.9 K. The arc magnets are the main magnets that guide the proton beams around the LHC circumference to the collision points.

The Large Hadron Collider’s have been cooled to their superconducting operating temperatures at 1.9 kelvin. The online charts of the temperatures show all eight sectors of the LHC cooled.

This is a major milestone in the restart of the LHC and bodes well for the further operations this year. CERN plans to start circulating the proton beams in November and aims for first collisions sometime after mid-December.

You can read more about the latest status of the LHC in this week’s CERN Bulletin.

David Harris

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The future of neutrino physics in Europe

October 13, 2009 | 9:54 am

Worker in the CERN Neutrinos to Gran Sasso (CNGS) tunnel at CERN. Image © CERN.

For three days last week, more than 250 scientists gathered at CERN in Geneva, Switzerland to discuss the future of European participation in the field of neutrino physics.

Neutrinos are a hot topic of study among the physics community because their properties may explain the existence of a universe made of matter. Neutrinos interact so little with other particles that trillions of them pass through our bodies without leaving a trace. They are by far the lightest of the known particles, and are also the least understood.

The European Strategy for Future Neutrino Physics workshop was a step toward establishing a roadmap for European participation in neutrino physics, and increasing coordination both within the European neutrino physics community and between the European community and the rest of the world.

Experiments underway around the world now and over the next five years may greatly advance our understanding of neutrinos, but physicists expect they will need to learn more. The possibilities for new accelerator-based neutrino facilities beyond 2015, and the R&D necessary over the next few years to determine the direction of neutrino research, were the focus of last week’s workshop.

The workshop, organized by a special panel of the CERN Scientific Policy Committee, also investigated the role that CERN could play in the future of European and worldwide neutrino physics facilities. CERN has a long history of involvement in neutrino physics, including the use of neutrinos to discover the weak neutral current.  But today, CERN’s involvement in neutrino physics is limited to creating beams of neutrinos for experiments at Gran Sasso Laboratory in Italy.

The SPC panel will present a report to the CERN Council in December, for which last week’s workshop provided critical input. The CERN Council is responsible for setting European strategy for particle physics as well as for deciding on future directions for the CERN laboratory.  The report will address the feasibility and merit of a European neutrino physics strategy as well as the possibilities for CERN, whether future facilities are located in Europe or elsewhere in the world.

For more information, visit the agenda for the meeting, which includes all presentations given at the meeting and abstracts for the 44 posters presented

Katie Yurkewicz

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A scientist, a humanist, and social scientist are stuck on a desert island…

October 12, 2009 | 11:29 am

If you had a scientist, a humanist, and a social scientist stranded on a desert island, and room in a life raft for just one of them, which one would you save? Don’t base it on personal affection–but on which discipline you think can most benefit the future of humanity.

That’s the premise of the “Raft Debate,” at the College of William and Mary, in which a representative of three different disciplines defends why they should get the spot in the raft–or rather, why their discipline is the most important to the future of human civilization, and hence why they should be chosen to return to society and carry the torch. Three professors sit on stage with a blow up life raft in front of them and present their cases to an audience and group of judges, who ultimately decide the survivor.

“What’s the point of all this?,” said W&M Dean of Graduate Studies and Research, Arts & Sciences judge Laurie Sanderson. “Certainly, one point is to have fun with an intriguing question and then go eat cake. Or maybe we’re showing that each one of these disciplines does have importance in society.”

The debate is good-natured and fun, demonstrated by the creative means that each professor uses to illustrate his or her case (to show that he was “fishing for arguments,” the humanist handed the social scientist a fishing pole with a boot at the end). And to be totally objective, the representatives are challenged by one devil’s advocate who argues that none of them deserve the raft (perhaps if they push it off the island, someone will find it who has a greater respect for cross-disciplines).

At this year’s debate, the natural sciences were defended by particle and nuclear physicist David Armstrong, a professor at William and Mary who also does research at Jefferson Lab and TRIUMF.

Armstrong begins his defense of science with the allegory of Gilligan’s Island.  “Seven castaways on a deserted isle was the perfect microcosm for the academic world,” he said.

The Captain represents government, helpful Mary-Anne education, dramatic Ginger the arts, and nosy Gilligan the social sciences. But the character they all turned to to save them was always the professor.

But Armstrong wasn’t just talking about coconut radios. Rather, he argued that the essence of science, the study of reality, was what made it crucial to keeping society in balance.

“Science confronts the reality of nature of the universe around us,” he said. “Reality, not swayed by rhetoric or force of emotionality. We are all quite literally stardust. What could be more human? What could be more poetic?” Later, in the rebuttals he added, “If you want to survive, if you want humanity to survive, you must understand how the world works. You need the scientist.”

In the end, the devil’s advocate actually argued that all three could find a way to fit on the life raft if they joined thoughtful forces. But the judges did have to crown a winner to keep with tradition, and Armstrong’s arguments for natural science won him a seat on the raft and tremendous cheers from the crowd. What great weight does science bear, now that it has been chosen to ride back to civilization?

The content of this article was drawn from a piece in the Dog Street Journal, the daily paper and monthly magazine of William and Mary, and this article from their News and Events page. Check them out to hear more of Armstrong’s arguments as well as what the other two professors had to say.

Calla Cofield

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Who will lead innovation in the future?

October 9, 2009 | 11:11 am

Tona Kunz

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Name that particle smasher – no really, name it.

October 8, 2009 | 10:10 am

Fermilab has asked the general public for suggestions of what to name their next big accelerator–currently known as ProjectX. Deputy Director Young-Kee Kim told the New York Times that Fermilab was accepting suggestions, and since the article ran on October 6, Kim has received over one hundred emailed suggestions. You can send your suggestions to ykkim@fnal.gov, and see a current list of suggestions from readers and physicists here.

What would you call it if it were up to you? Would you give it a powerful, superhero name like the Smashatron? Would you name it something beautiful and poetic, like IBIS (Intense Beam InStallation, and the Egyptian god of knowledge)? Whatever your pleasure, your idea might actually become fixed in particle physics history.

In 2011, after the LHC has taken over as the largest operational particle accelerator in the world, Fermilab’s Tevatron will shut down after more than three decades of operation. ProjectX will be even larger than the Tevatron, and will utilize some of the old hardware and infrastructure.

We should note that Fermilab is asking for suggestions, but this is not a contest to pick a winner. However, we’d love to see Stephen Colbert get a hold of this naming process as he did with NASA’s contest to name a wing of the International Space Station. If you haven’t heard, their plan took an unexpected turn when the host of Comedy Central’s The Colbert Report, rallied his viewers to write in his name next to the four suggestions put forth by NASA. They did, and it won. NASA agreed to name a $5 million treadmill after Mr. Colbert, but named the wing of the space station Tranquility. The Colbert Collider? It has a ring to it.

Some of my favorites thus far: The Ferminator, The Big Bopper, the Mother of all Particle Colliders, HIPPO (High Intensity Paperwork Production Originator), HULK (Humanitys Ultimate Library of Knowledge), HULK SMASH, and SUP-R-FREQ (Pronounced Super Freak and standing for “superconducting radio frequency”).

Kim said that many of the submitters also expressed their appreciation at Fermilab asking the public to participate in the creation of this new accelerator.

Calla Cofield

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MicroBooNE experiment receives approval of "mission need"

October 7, 2009 | 8:59 am

This story first appeared in Fermilab Today on October 7, 2009.

The MicroBooNE experiment will use a time-projection chamber filled with about 100 tons of liquid argon to look for anomalies in low-energy neutrino interactions.

Fermilab has moved a step closer to constructing a new neutrino experiment. The Department of Energy has given Critical Decision-0 approval to a new Booster Neutrino Experiment called MicroBooNE. The experiment will look for potential anomalies in low-energy neutrino interactions, which were first reported by the MiniBooNE experiment at Fermilab in 2007. MicroBooNE will use the same neutrino beam that traverses the MiniBooNE detector and explore the behavior of muon neutrinos made by a proton beam from the Booster accelerator at Fermilab.

The CD-0 approval establishes DOE mission need for the MicroBooNE experiment. The MicroBooNE collaboration now will develop detailed engineering plans for further DOE review and determine the final cost of the experiment, which will be less than $20 million. Scientists hope to receive CD-1, 2, and 3 approvals before the end of 2010 to begin the construction of the experiment as soon as possible. About 60 scientists from 13 institutions work on the experiment.

The MiniBooNE experiment, which still takes data, uses light-sensitive sensors and a tank filled with more than 800 tons of highly transparent mineral oil to catch neutrinos. In contrast, MicroBooNE will feature the largest liquid-argon time projection chamber ever built in the United States. Its TPC will hold about 100 tons of liquid argon cooled to minus 187 degrees Celsius. The TPC will be 12 meters long and have a width and height of 2.5 meters, making it more than 300 times larger than the largest liquid-argon chamber in the United States, which is located inside the Argon Neutrino Test detector at Fermilab.

The liquid-argon TPC technology allows scientists to record detailed tracks of charged particles emerging from neutrino-argon collisions, similar to particle tracks recorded by bubble chambers. The ArgoNeuT detector recorded its first tracks from neutrino interactions in June.

“We have made tremendous progress with the liquid-argon technology in the last three years,” said Yale University physicist Bonnie Fleming, spokesperson of the MicroBooNE experiment. “We now have the knowledge to build an important neutrino experiment with this technology. Equally important, MicroBooNE is a crucial step toward developing a liquid-argon neutrino detector for the proposed Long Baseline Neutrino Experiment.”

LBNE would analyze a neutrino beam traveling more than 1000 kilometers through the earth. The experiment requires detectors that contain tens of kilotons of material and can identify particle interactions with great accuracy.

Kurt Riesselmann

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Beyond the Nobel: The largest ever CCD digital cameras will explore the universe

October 6, 2009 | 11:01 am

This morning, the Nobel Prize in Physics was awarded to three researchers who made advances in optical technologies. Charles Kao won the half the prize for leading the search for development of optical fibers that could transmit information over large distances. Willard Boyle and George Smith shared the other half for their development of charge-coupled devices, or CCDs, the sensors that lie in digital cameras.

Design of the LSST camera, current as of Nov 2007. The LSST camera is designed to provide a wide field of view with better than 0.2 arcsecond sampling and spectral sampling in five or more bands from 400nm to 1060nm. The image surface is flat with a diameter of approximately 64 cm. The detector format will be a circular mosaic providing over 3 Gigapixels per image. The camera includes a filter mechanism and, if necessary, shuttering capability. The camera is positioned in the middle of the telescope. (Image credit: LSST Corporation)

At symmetry, we are particularly interested in CCDs as they lie behind an upcoming telescope that will lead to a huge step in our understanding of dark matter and dark energy. The Large Synoptic Survey Telescope, or LSST, physically located in Chile, will rapidly scan the sky making the most detailed maps of stars and galaxies ever created. It will be capable of detecting extremely faint objects and so will be looking further into the distance than any other telescope mapping the whole sky, while also observing small, fast-moving, nearby objects.

The telescope is made of a set of optics to collect and focus the light and a CCD camera to collect that light. The CCD camera design and construction is being led by the Kavli Institute for Particle Astrophysics and Cosmology at SLAC National Accelerator Laboratory and Stanford University. It will be the largest CCD camera ever made, featuring 3.2 gigapixels, which is 3200 megapixels for comparison with your home digital camera.

The largest existing digital camera is the Panoramic Survey Telescope & Rapid Response System, or Pan-STARRS, camera which has 1.4 gigapixels. The PS1 is the first of four matching telescopes that will be used primarily for detecting potentially hazardous objects in our solar system. It will also be making various astronomical observations. Conversely, the LSST will be used primarily for astrophysics but will also be able to track asteroids and other space hazards.

The basic idea of a CCD is that when photons hit the surface of the device, electrons are released from the material (in a process called the photoelectric effect, for which Einstein won the Nobel Prize), and those electrons collect at the surface. The amount of electric charge that builds up represents how much light hit that spot. After some exposure time, that charge all gets ferried to the side of the detector, in a row-by-row readout mechanism, where it is counted and converted to a string of numbers to form the digital image.

The detailed mass distribution in the cluster CL0024 is shown, with gravitationally distorted graph paper overlaid. This detailed dark matter distribution can be used to constrain theories of dark matter. Observed strong lensing of a background galaxy was inverted to yield a model for the mass distribution. This model was used to calculate the lensing effect on orthogonal graph paper were it placed behind the gravitational lens.

Making large CCDs for astronomical purposes present all kinds of challenges beyond what you need to do for a home digital camera. For a start, any digital camera suffers from electronic noise, where extra electrons pop up and remain as extra charge on the camera surface, as if from a phantom photon. You’ll see some digital cameras advertising their low-noise sensors, talking about this very problem. The issue is much more acute for LSST as the telescope will only be collecting small numbers of photons from many faint sources, so just a few stray electrons can ruin the image. Heat is enough to eject some unwanted electrons so the whole LSST camera needs to be cooled to liquid nitrogen temperatures to reduce noise.

With a camera so large, the time taken to readout the charge build-up becomes an issue. That means the detector is made as a mosaic of smaller elements, all able to be read out at once. Even so, it will still take up to about two seconds to read all the data from an image, about the time it take for the camera to reposition itself for the next image. Dealing with that much data is also a challenge, and the telescope will collect about 30 terabytes of data each night. That puts the data collection needs in the range of many large particle physics projects. Entire new computing systems are being developed for the LSST to handle the data.

With all this data, the LSST will be able to reconstruct the detailed mass distribution in the universe, based on how it bends light during the process of gravitational lensing. From that information, scientists will be able to understand a lot more about the nature and distribution of dark matter and its role in the formation of galaxies and clusters of galaxies. By looking at distant objects, LSST will effectively be looking back in time so it will be able to observe how the universe has evolved, leading to insights about how dark energy has influenced that evolution and giving hints as to what dark energy might actually be.

It’s a long way from some innovative scientists experimenting in their laboratory to understanding the evolution of the universe, but CCDs have become an essential part for a vast range of science, from the microscopic to the cosmic.

David Harris

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Indian institutions, Fermilab team up for SRF technology

October 6, 2009 | 9:16 am

From left: Rajeshwar Singh Sandha, RRCAT; Jishnu Dwivedi, RRCAT; Rohan Mittal, Devi Ahilya; Fermilab's Joe Ozelis and Archana Sharma, BARC.

Technical specifications and instructions help, but as Jishnu Dwivedi knows, building a superconducting radio frequency cavity requires more than a few thousand pages of text and diagrams.

“When you read from books, a lot of information does not directly apply to your project,” said Dwivedi, a mechanical engineer visiting Fermilab from the Raja Ramanna Center for Advanced Technology in India. “By being here, we can see the components and get a good feel of the design, manufacturing and testing requirements.”

In September, Dwivedi finished a three-month stay at Fermilab’s Technical Division as part of the collaboration formalized in February between four Indian institutions and Fermilab. Back in India, the collaboration is working on its first single-cell cavity, which will be shipped to Fermilab for processing and testing, Dwivedi said. He expects a more complex multi-cell cavity to be ready in about a year.

Physicists and engineers from Indian institutions are involved in all aspects of Fermilab’s SRF development that supports future accelerators.  Responsibilities include design and fabrication for a new type of cavity and cryomodule, along with corresponding test stands.

“We are making reasonable progress, but it is up to Fermilab to effectively use the technical resources made available by Indian institutions to Fermilab,” said Shekhar Mishra, deputy director for the International Linear Collider program at Fermilab and director of Fermilab’s SRF program.

Since 2007, about 20 scientists and engineers stationed at collaborating Indian institutions have been working with Fermilab scientists on superconducting cavity design for the next generation of particle accelerators. Like Dwivedi, visiting Indian collaborators provide a communication bridge between the technical work in India and Fermilab.

By working with Fermilab, Dwivedi estimates the Indian collaboration will be able to finish work three times faster than it would have otherwise.

“People have been very helpful at Fermilab,” Dwivedi said. “They took special care to explain the fundamentals. We are grateful for all the support.”

One of those helpful people was Marty Whitson, production supervisor for magnet research and development for the LHC Accelerator Research Program. Whitson showed Dwivedi how Fermilab uses a thin foil strip called a strain gauge to measure small changes in metal.

“I demonstrated the techniques to apply the strain gauges and I gave them the documentation from the classroom and showed the skills you need to apply them,” Whitson said.

The Indian collaborators eventually want to build the infrastructure to fabricate, process and test cavities for a proposed Project X at Fermilab and a proposed High Intensity Proton Accelerator in India.

Scientific collaboration between Fermilab and Indian institutions dates back to the ’70s. A general Memorandum of Understanding formalized collaboration three years ago, followed by an addendum to collaborate on the proposed Project X in February 2009.

– Chris Knight

Symmetry Intern

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Not the Nobel, but Higgs shares major theoretical physics prize

October 5, 2009 | 2:47 pm

With the announcement of the 2009 Nobel Prize in Physics due tomorrow, there has been much speculation about who the winner(s) might be. Companies like Thomson Reuters, who sell their scientific citation database information, always get a bunch of publicity for their predictions based on citations, although there is some evidence that the power of citation counts for predicting the physics prize is weakening.

Regardless, there are many people who think that a Nobel Prize will be awarded for the Higgs particle. But what prize precisely and to whom? There is the theoretical development that was published by three groups in 1964, and the possible experimental finding that could come in the next few years.

At the moment, there is no particular incentive for the Nobel committee to rush through a Prize honoring the theoretical development unless they want to look like they are ahead of the game with experimental discovery potentially imminent. Back in 1997, groups led by Eric Cornell, Carl Weiman, and Wolfgang Ketterle all created long-sought Bose-Einstein condensates in gases of alkali metal elements. And many speculated they would win the Prize. Instead, their discovery was quickly followed by the award of the 1997 Nobel Prize in Physics to Steven Chu, Claude Cohen-Tannoudji, and Bill Phillips for the experimental technique of cooling and trapping gases using lasers. Cornell, Weiman, and Ketterle won the prize themselves in 2001. So perhaps there could be a prize for Higgs theory first, but they committee might wait until the experimental discovery to make sure they are right. After all, the Higgs mechanism might not be the right approach to explaining how particles get mass, although it has been incredibly powerful in the development of particle physics ideas. The Nobel for the theoretical development of the electroweak theory was awarded prior to the discovery of the W and Z bosons that gave the solid evidence it was correct so there are precedents either way.

But let’s suppose that the Nobel committee wants to award a prize for the theoretical work behind the Higgs mechanism. They would probably want to recognize precisely the group that has just won the 2010 J.J. Sakurai Prize, awarded by the American Physical Society. That prize will be presented in February at the APS “April” meeting in Washington, DC, but has been announced as going to Carl Hagen, Francois Englert, Gerald Guralnik, Peter Higgs, Robert Brout, and Tom Kibble “for elucidation of the properties of spontaneous symmetry breaking in four-dimensional relativistic gauge theory and of the mechanism for the consistent generation of vector boson masses.”

Read the rest of this entry »

David Harris

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Tune in to the LHC

October 5, 2009 | 7:03 am

Want to keep up with the Large Hadron Collider’s status, schedules and milestones? Check out CERN’s LHC News video series on YouTube. The regular reports use video, animations, interviews, and commentary to inform the public about the status of repairs and the start-up schedule of the accelerator, as well as the major milestones of the LHC experiments.

“A lot has happened during the past few months, the LHC has achieved many milestones on time, but people have difficulty understanding why it takes so long to make accelerators operational-it is not exactly like switching a microwave on!” says Paola Catapano, who produces and directs the videos with colleague Silvano De Gennaro in the CERN Communication Group.  “LHC News is one way CERN uses to keep public interest in the LHC high by creating suspense as to what’s happening next and when we are going to switch on again.”

And the interest is definitely there: the special report “Why did the LHC break down?” has been viewed over 96,000 times, more than NASA’s video of the last  Space Shuttle lift-off.

Watching the LHC News, you will not only visit the accelerator tunnel and the experiments’ caverns, but you will actually see the magnets being repaired and peek over the shoulders of scientists in the control rooms. You will learn first-hand what is going on at CERN, and meet people who are coming from all over the world to participate in the LHC endeavor.

So don’t miss the next episodes!

by Manuela Cirilli

Guest author

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