David Kirkpatrick

August 9, 2010

The particle accelerator as power generator

Filed under: Science — Tags: , , , , , — David Kirkpatrick @ 12:49 pm

Not as far fetched as you might think.

From the link:

Using this back-of-an-envelope calculation, Wilson worked out that a single 1000 GeV proton could lead to the release of 12,000 GeV of fission energy. Of course, this neglects all the messy fine details in which large amounts of energy can be lost. For example, it takes some 20MW of power to produce an 0.2MW beam in the Energy Doubler.

But even with those kinds of losses, it certainly seems worthwhile to study the process in more detail to see if overall energy production is possible.

Wilson’s conclusion is this: “There are probably better ways of producing plutonium, but it does appear that it would be feasible to construct an intense proton accelerator that would produce more energy than it consumes.”

March 14, 2009

Stalking the Higgs boson

Filed under: Science — Tags: , , , , — David Kirkpatrick @ 2:49 pm

News from Fermilab:

Fermilab experiments constrain Higgs mass

CDF, DZero experiments exclude significant fraction of Higgs territory

Batavia, Ill.—The territory where the Higgs boson may be found continues to shrink. The latest analysis of data from the CDF and DZero collider experiments at the U.S. Department of Energy’s Fermilab now excludes a significant fraction of the allowed Higgs mass range established by earlier measurements. Those experiments predict that the Higgs particle should have a mass between 114 and 185 GeV/c2. Now the CDF and DZero results carve out a section in the middle of this range and establish that it cannot have a mass in between 160 and 170 GeV/c2.

“ The outstanding performance of the Tevatron and CDF and DZero together have produced this important result,” said Dennis Kovar, Associate Director of the Office of Science for High Energy Physics at the U.S. Department of Energy. “We’re looking forward to further Tevatron constraints on the Higgs mass.”

The Higgs particle is a keystone in the theoretical framework known as the Standard Model of particles and their interactions. According to the Standard Model, the Higgs boson explains why some elementary particles have mass and others do not.

So far, the Higgs particle has eluded direct detection. Searches at the Large Electron Positron collider at the European laboratory CERN established that the Higgs boson must weigh more than 114 GeV/c2. Calculations of quantum effects involving the Higgs boson require its mass to be less than 185 GeV/c2.

“A cornerstone of NSF’s support of particle physics is the search for the origin of mass, and this result takes us one step closer,” said Physics Division Director Joe Dehmer, of the National Science Foundation.

The observation of the Higgs particle is also one of the goals of the Large Hadron Collider experiments at CERN, which plans to record its first collision data before the end of this year.

The success of probing the Higgs territory at the Tevatron has been possible thanks to the excellent performance of the accelerator and the continuing improvements that the experimenters incorporate into the analysis of the collider data.

“Fermilab’s Tevatron collider typically produces about ten million collisions per second,” said DZero co-spokesperson Darien Wood, of Northeastern University. “The Standard Model predicts how many times a year we should expect to see the Higgs boson in our detector, and how often we should see particle signals that can mimic a Higgs. By refining our analysis techniques and by collecting more and more data, the true Higgs signal, if it exists, will sooner or later emerge.”

To increase their chances of finding the Higgs boson, the CDF and DZero scientists combine the results from their separate analyses, effectively doubling the data available.

“A particle collision at the Tevatron collider can produce a Higgs boson in many different ways, and the Higgs particle can then decay into various particles,” said CDF co-spokesperson Rob Roser, of Fermilab. “Each experiment examines more and more possibilities. Combining all of them, we hope to see a first hint of the Higgs particle.”

So far, CDF and DZero each have analyzed about three inverse femtobarns of collision data—the scientific unit that scientists use to count the number of collisions. Each experiment expects to receive a total of about 10 inverse femtobarns by the end of 2010, thanks to the superb performance of the Tevatron. The collider continues to set numerous performance records, increasing the number of proton-antiproton collisions it produces.

The Higgs search result is among approximately 70 results that the CDF and DZero collaborations presented at the annual conference on Electroweak Physics and Unified Theories known as the Rencontres de Moriond, held March 7-14. In the past year, the two experiments have produced nearly 100 publications and about 50 Ph.D.s that have advanced particle physics at the energy frontier.

Notes for editors:

Fermilab, the U.S. Department of Energy’s Fermi National Accelerator Laboratory located near Chicago, operates the Tevatron, the world’s highest-energy particle collider. The Fermi Research Alliance LLC operates Fermilab under a contract with DOE.

CDF is an international experiment of 602 physicists from 63 institutions in 15 countries. DZero is an international experiment conducted by 550 physicists from 90 institutions in 18 countries. Funding for the CDF and DZero experiments comes from DOE’s Office of Science, the National Science Foundation, and a number of international funding agencies.

CDF collaborating institutions are at http://www-cdf.fnal.gov/collaboration/index.html

DZero collaborating institutions are at http://www-d0.fnal.gov/ib/Institutions.html

Graphics, photos and videos are available at:
http://www.fnal.gov/pub/presspass/press_releases/Higgs-mass-constraints-20090313-images.html

August 23, 2008

Fermilab finds single top quark

Filed under: Science — Tags: , , , , , , — David Kirkpatrick @ 2:30 pm

In the category of further breaking down the atom, Fermilab announces “seeing” a top quark not coupled to an antiop.

It’s always great news whentheoretical atomic properties are found to exist, but this announcement is a bit funny because there’s a strong undercurrent of, let’s say, friendly competition with CERN and the soon-to-be-turned-on Large Hadron Collider for the media’s attention.

This can readily be seen in the intro to the linked article (emphasis mine):

Scientists at the world’s largest fully operating particle accelerator, the Tevatron at Fermi National Accelerator Laboratory (Fermilab) in Illinois, have discovered convincing evidence suggesting the existence of top quarks that are not coupled to their antiparticle, the antitop. These “single” top quarks have been hunted since Fermilab scientists first discovered top-antitop pairs in 1995.

Luckily the Tevatron has a few more years of no real competition in terms of grand announcements since LHC isn’t expected to begin kicking out confirmed results for around that period of time

Enough of Fermilab/CERN comparisons. Here’s the science from the piece:

Fermilab physicists hope that the techniques they used to find the single top quark could help them in their search for the proposed Higgs boson, a particle that exists so far only in theory but if actually found would have a huge impact on physics. The Higgs is expected to reveal such basic information as why nature assigned certain masses to certain particles—the origin of mass, essentially.

The results are the product of a long period of analysis by Fermilab’s D0 (“D-Zero”) collaboration, an international group of physicists from 90 institutions. The group studies data from particle collisions that occur within the D0 particle detector; in this case, data generated by collisions between a beam of protons and a beam of antiprotons. D0 is a building-sized cylindrical device that surrounds the collision site, measuring and recording the energies and trajectories of the many, many particles produced when the beams are smashed together.

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