Berkeley plan to demolish Bevatron has some concerned

July 22, 2008 | 3:56 pm

The Bevatron. Image courtesy of LBNL.

Lawrence Berkeley National Laboratory plans to tear down its historic Bevatron particle accelerator, which was instrumental in discoveries that led to four Nobel Prizes.  Built under the direction of E.O. Lawrence, it opened in 1954 and closed in 1993 after research moved to newer facilities. 

But as reported in today’s Oakland Tribune, the demolition has run into opposition from people worried that busting up the machine, which contains low levels of radiation, might harm the health of people living nearby and along the routes where the debris will be trucked out.

The Berkeley City Council will consider a resolution tonight asking the Department of Energy to prepare a more detailed environmental report, answer a list of questions about the demolition plan and tear down the machine itself before the surrounding building is demolished, the newspaper reports:

The demolition project could start as early as August and is expected to be completed in 2011 at an estimated $72 million cost. Though the lab doesn’t have plans for the land that will be cleared, space for new research facilities is at a premium on the crowded, hilly campus.

The council does not have authority over what ultimately will happen to the Bevatron. But town-gown relations are always important and the lab has maintained that the demolition can be done without any danger to the public.

“Under the current plan, Berkeley Lab will dismantle and remove the Bevatron and surrounding blocks prior to the demolition of the building that contains them. The lab will inform the city of significant milestones throughout the project’s lifespan,” read a letter from lab spokesman Don Medley.

It’s been a sad year for old atom-smashers; Columbia University recently dismantled what was left of its 72-year-old cyclotron, which had been closed down for years.  The August issue of symmetry will feature an essay by one of the many students who used to spelunk, through a network of underground tunnels, into the basement room where the machine once hummed.

The Bevatron

… played the leading role in three of the most important discoveries of particle physics: experimental studies of “strange” particles leading to the discovery of parity nonconservation (the first known example of a lack of symmetry in nature); the discovery of nuclear antimatter (the antiprotons and the antineutron); and the discovery of the “resonances” — the particle explosion of the 1960’s that led to the development of the quark model and the current understanding of the basic nature of matter.

That’s from an article written by LBNL’s Judy Goldhaber  in 1992.

Glennda Chui

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What's colder than outer space? The LHC, soon.

July 21, 2008 | 4:19 pm

An LHC cryomagnet. Image courtesy of CERN.

One of the most delicate and exacting parts of bringing the Large Hadron Collider into full operation is cooling the magnets in its 27-kilometer ring to a temperature of 1.9 degrees Kelvin.  That’s colder than deep space, according to this engaging account of the cooldown process by BBC News:

No particle physics facility on this scale has ever operated at such low temperatures. But, so far, the hardware was performing as predicted, Roberto Saban explained.

“We have a very systematic process for the commissioning of this machine, based on very carefully designed procedures prepared with experience we have gathered on prototypes.”

He added: “Our motto is: no short cuts… exchanging a single component which today is cold, is like bringing it back from the Moon. It takes about three to four weeks to warm it up. Then it takes one or two weeks to exchange. Then it needs three to six weeks to cool down again.

“So, you see, it is three months if we make a mistake.”

Glennda Chui

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Packing metal in fangs, claws and jaws

July 18, 2008 | 11:58 am

The fangs of Araneus diadematus, the European garden spider. The frames (2x2 micrometers) show deposits of zinc (upper right), manganese (lower left) or both (lower right). The metals strengthen the spider fangs.

Spiders don’t have flashy metal fangs, but they do rely on metal deposits to make their fangs extra strong and fracture resistant. Scorpions, crabs, worms and other creatures also have metal atoms in their claws, jaws and fangs. These deposits are an evolutionary feat of engineering; they make the structures significantly stronger and longer lasting. Rather than occurring in organized clusters of atoms—a shiny strip of tin foil is one example—they are single atoms held in place by non-metals. This is part of the reason that no one discovered these deposits until about 30 years ago: it is difficult to detect a single atom unless you are specifically looking for it. Moreover, the metals—mainly iron, copper, manganese and zinc—are present only in very small parts of the animal. This may include the very tips of scorpion or crab claws, the tiny fangs of spiders, or the jagged teeth on the mandibles of ants. The structures are small but undergo proportionally large stresses as they come into contact with the environment.

Robert M. S. Schofield of the University of Oregon, Michael H. Nesson of Oregon State University and Robert A. Scott of the University of Georgia are surveying as many creepy-crawlies as possible with a microprobe at Stanford Synchrotron Radiation Laboratory, hoping to shed light on the development of their unique structures and find common ancestors of these highly varied creatures. They detect the deposits with high-energy particle techniques, though not necessarily synchrotron radiation. Proton Induced X-Ray Emission (PIXE) and Scanning Transmission Ion Microscopy can determine the location and identity of individual elements on the scale of a few microns. X-ray synchrotron radiation, like that at SSRL, reveals the chemical environment, including the presence of individual atoms, their ionization state, and a hint at the metal and non-metal molecular structure. The next step is finding a way to look at those molecular structures directly.

Researchers would like to understand how these strong structures are built, and how individual metal atoms can change their properties. Fracture-resistant materials are usually soft and will bend or deform under pressure. But the structures in these organisms are hard as well as fracture resistant. “I don’t think that these materials are record holders in any particular category—for example, diamonds will certainly be harder. It is the mix of properties that is important,” Schofield says. “It may be that mimicking these materials will lead to man-made materials with an optimum balance of properties for certain small-scale tasks.”

The metals accumulate after molting, as the animals grow into adulthood. Researchers monitored the percentage of metal deposits at different times during development and observed the channels through which the metals migrate into appendages. They found that different metals settle in different areas: zinc is found in the tips of spider fangs while manganese is found in the trunk. Often, metal atoms in the newly hardened structures are also paired with specific non-metals: zinc with chlorine, and manganese with calcium. In the image above, the upper right frame shows X-ray detection of zinc; the lower left shows X-ray detection of manganese. The lower right frame combines the images: zinc is green and manganese is red.

Now that researchers know to look for them, these deposits are surfacing in a wide variety of species. Including the current survey, metal atoms have been found in 136 species of insects, 30 species of arachnids, 12 species of polychaete worms and four species of centipedes. Even so, there are still thousands of species to examine. Ultimately, researchers hope that understanding this biological pattern found in so many current species will guide the search for a common ancestor. Schofield explains that the appearance of new biomaterials has played a central role in evolution, and these metal atom structures should be no different. Biomaterials can open the door for organisms to develop drastically new characteristics, and even lead to extinction or evolution of new species.

Calla Cofield

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DAMA result is not "normal" dark matter

July 16, 2008 | 12:13 pm

The intriguing signal from the DAMA/LIBRA experiment in Italy has been ruled out as a sign of “normal” dark matter, according to new experimental data by the CoGeNT collaboration.

The DAMA results have long been controversial but the newest result shows an unequivocal sign of something-it’s just not clear what that something is and whether it is dark matter. Other dark matter searches have ruled out the kinds of dark matter particles that are consistent with the DAMA results, piece by piece, but there was always an opening for very light dark matter particles.

The CoGeNT results, along with results from the COUPP bubble chamber experiment (more on COUPP in the upcoming print issue of symmetry), rule out the possibility of there being very light dark matter particles spread about in a galactic halo, the “normal” kind of dark matter that is usually proposed, and that would have led to the kind of signal that DAMA/LIBRA observed.

However, the authors of the paper presenting the CoGeNT results point out that there could be some particularly exotic form of dark matter such as axions, Q-balls, or particles predicted by some of the more complicated versions of supersymmetry.

Experiments designed for neutrino detection, such as MAJORANA, should be able to look for some of those exotic dark matter candidates.

All this leaves open the question: “What did DAMA really see?” It now appears unlikely that it was dark matter but there are no other convincing explanations.

David Harris

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Quick thinking helps experiment stay afloat

July 15, 2008 | 9:43 am

The IATL building and Iowa Memorial Union

The flood waters crept up. The lights went out. Yasar Onel and about a dozen of his students were not about to let angry Midwest weather wash away the University of Iowa’s part in the world’s largest physics experiment.

Post-docs Ugur Akgun and Taylan Yetkin helped take the lead grabbing the delicate quartz plates and read-out systems crucial for the CMS experiment at CERN and rushing for the van. “We were told we had two hours to leave before the highways were closed to traffic. So we packed as much as we could and headed for Fermilab,” said Onel, an Iowa University professor and CMS collaborator.

Foot bridge next to the IATL building looking west toward the art campus.

What was usually a two and a half hour drive took over seven hours. When they arrived at Fermilab support came from all levels.

“They already knew our problem and took us in. They gave my students housing, did all the paperwork for shipment and let us complete our work in Lab 7,” Onel said. “I couldn’t believe all the support. The cooperation was really, really great.”

CMS detector at CERN

The help enabled the group to make its deadline with CMS colleagues at CERN, preventing a possible test beam delay. Other researchers at the university weren’t so lucky. More than 16 buildings flooded and officials expect it could take six months or more to replace or fix some equipment.

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Guest author

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ANTARES neutrino telescope complete

July 14, 2008 | 5:59 pm

The latest generation of neutrino telescopes uses vast bodies of salt water, fresh water, or ice as the medium for detecting neutrinos. The ANTARES experiment, which recently announced that it has completed construction, is the salt water version, based at the bottom of the Mediterranean Sea.

You can read more about the completion of ANTARES in New Scientist in a report by Rachel Courtland (a former symmetry intern). We also wrote about these neutrino experiments in the very first issue of symmetry magazine back in October 2004.

ANTARES is a real engineering accomplishment because the detectors need to be deep in the water to avoid background signals from cosmic rays. That means they need to be securely attached to the ocean floor, 2500 meters below sea level; able to withstand the high pressure environment; and in positions known well enough that scientists can determine precisely where the neutrinos are.

To get a sense for the challenge of that last problem, imagine attaching a bunch of lightweight cameras to a string of helium balloons that extended hundreds of meters up into the sky. How do you know the precise location of any image the camera records when wind currents are buffeting the balloons and cameras all around? The 12 ANTARES strings of detectors anchored to the sea floor will move by up to 10 or 15 meters at their tops due to ocean currents and so sophisticated techniques are required to figure out just where a neutrino shows up.

However, physicists are confident they have solved this problem, along with the issues of bioluminescent sea creatures that cause false signals, the natural radioactivity of potassium in sea water also causing false signals, and getting power 40 kilometers along the sea floor to the detectors from the coast of France.

The ANTARES telescope has already seen many neutrinos created in the atmosphere but it is really hunting for neutrinos from cosmic sources, and to do that it is looking for particles that come all the way through the Earth. This strange form of neutrino telescope is right at the bottom of the ocean, but even then it is still looking downward.

David Harris

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It's official: Dark energy is in the dictionary

July 11, 2008 | 6:37 am

Merriam-Webster announced over the weekend that dark energy has been admitted into the new edition of its Collegiate Dictionary along with more than 100 other up-and-coming terms–from air quotes and edamame to dirty bomb, malware, mondagreen, and wing nut.

As the Associated Press reported:

The wordsmiths at the Springfield, Mass.-based publisher say they picked the new entries after monitoring their use over years.

“As soon as we see the word used without explanation or translation or gloss, we consider it a naturalized citizen of the English language,” said Peter Sokolowski, an editor-at-large for Merriam-Webster. “If somebody is using it to convey a specific idea and that idea is successfully conveyed in that word, it’s ready to go in the dictionary.”

Dark energy, defined as a “hypothetical form of energy that produces a force that opposes gravity and is thought to cause the accelerating expansion of the universe,” was first used in 1998, as far as the dictionary folks were able to determine.

Theoretical physicist Michael Turner of the University of Chicago, who coined the term, said to symmetry: ”Seventy-two percent of the universe and it took 10 years to get in?  About time!”

Actually, dark energy arrived on the fast track, relatively speaking.  Fanboy–a “boy who is an enthusiastic devotee, such as of comics or movies”–dates back to 1919.  And prosecco–a “dry Italian sparkling wine”–waited 127 years after its first known usage for this recognition.

Impatient?  Check out Merriam-Webster’s online Open Dictionary, which allows people to submit fresh terms for consideration.   Last we looked, recent entries included:

sandboni (noun) : a vehicle used on beaches to smooth sand

entremanure (noun) : a person, usually vociferous, who professes to own one or more non-existent business endeavors

moviehop (adjective) : To pay to see one movie at a cinema multiplex but hop from theater to theater watching several movies on the one ticket.

Glennda Chui

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Physicists discover new particle: the bottom-most "bottomonium"

July 9, 2008 | 4:30 pm

Thirty years ago, particle physics delighted in discovering the “bottomonium” family-the set of particles that contain both a bottom quark and an anti-bottom quark but are bound together with different energies. Ever since, researchers have sought to ascertain the lowest energy state of these tiny yet important particles. Now, for the first time, collaborators on the BaBar experiment at the U.S. Department of Energy’s (DOE) Stanford Linear Accelerator Center (SLAC) have detected and measured the lowest energy particle of the bottomonium family, called the ηb (pronounced eta-sub-b).

“Faced with the end of its run, the BaBar collaboration decided to focus its remaining time on investigating some of the states of bottomonium,” said Associate Director of the DOE Office of Science for High Energy Physics Dennis Kovar. “This exciting result achieves one of the principal aims of this final data collection run.”

SLAC Director Persis Drell added: “This is a tremendous achievement for both the PEP-II accelerator and the BaBar collaboration. Congratulations to everyone involved.”

Every system of matter contains a “ground state”-a lowest energy level to which the system is ever trying to get, shedding energy as it does so. The ground state provides a baseline from which to measure the other more energetic states of the particle, and is key to understanding the fundamental laws that govern how quarks interact and behave.

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Kelen Tuttle

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Dispelling science stereotypes one single at a time

July 9, 2008 | 6:28 am

The crowd of Chicago singles perused their most eligible peers: a doctor, a clothing designer, a successful entrepreneur, a professional baseball player, a physicist…

Wait. A physicist?

Yup. Particle astrophysicist Mark Jackson stood in the swanky Museum of Contemporary Art surrounded by many of the city’s rich and influential. While few people likely understood what he does for a living–study black holes and primordial ooze left over from the big bang–they did understand his nonacademic title: One of Chicago’s top 10 bachelors.

“In our search for successful, interesting candidates, some professions pop up year in and year out (doctors, lawyers, etc.), but we are always on the watch for people whose success is defined by more than just salary,” said Chicago Magazine editor Jennifer Wehunt “Mark revealed himself to be a down-to-Earth, funny, good-hearted guy.”

Jackson was selected as one of 10 men and 10 women ranked 2008 Most Eligible Singles in the magazine’s July issue.

Hundreds of people paid for a chance to meet the certified good catches last month at a fund-raiser for Northwestern Memorial Hospital’s prostate cancer gene therapy program at the museum.

Jackson got interested in the list when he attended the charity event previously and noticed none of the top singles had science backgrounds. He thought having a scientist on the list of would make the public think twice before they write off science as uncool.

“Scientists are very passionate about majestic problems like what the universe is made of or why things work at a very fundamental level, and it is sometimes it is sometimes difficult to communicate these deep ideas to the general public. It’s not like being an athlete or rock star, where everybody understands and admires the overall objective even if they don’t happen to be talented at it themselves. I think this is probably the reason we sometimes have a reputation for being antisocial, but in reality it’s just the opposite: scientists’ intelligence, sincerity, and sensitivity would make them ideal companions.”

Is he willing to get that message across to Chicago’s females one at a time?

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Tona Kunz

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Super B factories: competing proposals

July 8, 2008 | 10:25 am

Particle physicists have obtained stunning results from B factories, the colliders that produce large numbers of particles including bottom quarks. They have confirmed many Standard Model predictions about the behavior of bottom quarks and the strong force. They have demonstrated the predicted asymmetry between matter and antimatter in quarks, but also shown that it is not enough to explain all the difference between matter and antimatter.

The success of those machines–the BaBar experiment on the PEP-II collider at Stanford Linear Accelerator Center, and the Belle experiment on the KEKB collider at KEK in Japan–led physicists to dream of more powerful devices which would push the intensity frontier, generating so many B mesons that the existence and effects of extremely rare particles would become evident. Generate enough collisions with high-intensity beams and these rare particles could provide the answer to where the Standard Model of particle physics is incomplete and breaks down, as physicists know it must.

The new breed of colliders would be called Super B factories. Two competing proposals in the works have gained considerable attention and will soon be ready for consideration by funding agencies. An excellent overview of these is in Science magazine, written by Adrian Cho.

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David Harris

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