LOS ALAMOS, TOSHIBA PROBING FUKUSHIMA WITH COSMIC RAYS

MUON IMAGING: LOOKING INSIDE THE FUKUSHIMA DAIICHI REACTORS



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YOKOSUKA, Japan (March 16, 2012) Members from the Japan Women's Association present Capt. David A. Owen, commanding officer of Fleet Activities Yokosuka, paper cranes as a thank you for the services rendered by Sailors during Operation Tomodachi one year ago. Operation Tomodachi was a humanitarian mission focused on aiding the people of Japan in the aftermath of the massive earthquake and tsunami that struck Fukushima Prefecture in early March of 2011. (U.S. Navy photo by Mass Communication Specialist Seaman Paul Kelly/Released)
　

FROM: LOS ALAMOS NATIONAL LABORATORY

Tiny Travelers from Deep Space Could Assist in Healing Fukushima’s Nuclear Scar

Researchers examine use of cosmic-ray radiography on damaged reactor cores
LOS ALAMOS, NEW MEXICO, October 17, 2012—Researchers from Los Alamos National Laboratory have devised a method to use cosmic rays to gather detailed information from inside the damaged cores of the Fukushima Daiichi nuclear reactors, which were heavily damaged in March 2011 by a tsunami that followed a great earthquake.

In a paper in Physical Review Letters, researchers compared two methods for using cosmic-ray radiography to gather images of nuclear material within the core of a reactor similar to Fukushima Daiichi Reactor No. 1. The team found that Los Alamos’ scattering method for cosmic-ray radiography was far superior to the traditional transmission method for capturing high-resolution image data of potentially damaged nuclear material.

"Within weeks of the disastrous 2011 tsunami, Los Alamos’ Muon Radiography Team began investigating use of Los Alamos’ muon scattering method to determine whether it could be used to image the location of nuclear materials within the damaged reactors," said Konstantin Borozdin of Los Alamos’ Subatomic Physics Group and lead author of the paper. "As people may recall from previous nuclear reactor accidents, being able to effectively locate damaged portions of a reactor core is a key to effective, efficient cleanup. Our paper shows that Los Alamos’ scattering method is a superior method for gaining high-quality images of core materials."

Muon radiography (also called cosmic-ray radiography) uses secondary particles generated when cosmic rays collide with upper regions of Earth’s atmosphere to create images of the objects that the particles, called muons, penetrate. The process is analogous to an X-ray image, except muons are produced naturally and do not damage the materials they contact.

Massive numbers of muons shower the earth every second. Los Alamos researchers found that by placing a pair of muon detectors in front of and behind an object, and measuring the degree of scatter the muons underwent as they interacted with the materials they penetrated, the scientists could gather detailed images. The method works particularly well with highly interfering materials (so-called "high Z" materials) such as uranium. Because the muon scattering angle increases with atomic number, core materials within a reactor show up more clearly than the surrounding containment building, plumbing and other objects. Consequently, the muon scattering method shows tremendous promise for pinpointing the exact location of materials within the Fukushima reactor buildings.

Using a computer model, the research team simulated a nuclear reactor with percentages of its core removed and placed elsewhere within the reactor building. They then compared the Los Alamos scattering method to the traditional transmission method. The simulation showed that passive observation of the simulated core over six weeks using the scattering method provided high-resolution images that clearly showed that material was missing from the main core, as well as the location of the missing material elsewhere in the containment building. In comparison, the transmission method was barely able to provide a blurry image of the core itself during the same six-week period.

"We now have a concept by which the Japanese can gather crucial data about what is going on inside their damaged reactor cores with minimal human exposure to the high radiation fields that exist in proximity to the reactor buildings," Borozdin said. "Muon images could be valuable in more effectively planning and executing faster remediation of the reactor complex."

In addition to their potential utility at Fukushima, muon radiography portals have been deployed to detect potential smuggling of clandestine nuclear materials. These detectors can noninvasively find even heavily shielded contraband in minutes without breaching a container, vehicle or other smuggling device. Los Alamos researchers pioneered the concept shortly after the 9/11 terrorist attacks.

Other Los Alamos National Laboratory co-authors of the paper include Steven Greene, Edward "Cas" Milner, Haruo Miyadera, Christopher Morris and John Perry; and (former Los Alamos post-doctoral researcher) Zarija Lukic of Lawrence Berkeley National Laboratory. Cas Milner is credited by the team as the author of the original concept of applying muon imaging to Fukushima.

Los Alamos research on the project was made possible through Los Alamos’ Laboratory-Directed Research and Development Program (LDRD), which is funded by a small percentage of the Laboratory’s overall budget to invest in new or cutting-edge research. The U.S. Department of Energy supported contacts of the Los Alamos team with other research groups, including several Japanese institutions and the University of Texas.

SPACEDOCK

FROM:  NASA
Astronaut Ron Garan took this image during the spacewalk conducted on Tues., July 12, 2011. It shows the International Space Station with Space Shuttle Atlantis docked on the right and a Russian Soyuz on the far left. In the foreground is the Alpha Magnetic Spectrometer (AMS) experiment installed during the STS-134 mission.


AMS is a state-of-the-art particle physics detector designed to use the unique environment of space to advance knowledge of the universe and lead to the understanding of the universe's origin by searching for antimatter and dark matter, and measuring cosmic rays.

Image Credit: NASA

FINDING THE ORIGINS OF COSMIC RAYS AT THE BOTTOM OF THE WORLD

FROM:  NATIONAL SCIENCE FOUNDATION
Ice Cube Neutrino Observatory Provides New Insights Into Origin of Cosmic Rays
April 18, 2012
Analysis of data from the IceCube Neutrino Observatory, a massive detector deployed in deep ice at the U.S. Amundsen-Scott South Pole Station in Antarctica at the geographic South Pole, recently provided new insight into one of the most enduring mysteries in physics, the production of cosmic rays.

Cosmic rays were discovered 100 years ago, but only now are scientists homing in on how the highest energy cosmic rays are produced.

Cosmic rays are electrically charged particles, such as protons, that strike Earth from all directions with energies up to one hundred million times higher than those created in man-made accelerators.

The intense conditions needed to generate such energetic particles have focused physicists' interest on two potential sources: the massive black holes at the centers of active galaxies and exploding fireballs observed by astronomers called gamma-ray bursts or GRBs.

"Although we have not discovered where cosmic rays come from, we have taken a major step towards ruling out one of the leading predictions," said Francis Halzen, a physicist at the University of Wisconsin-Madison and the IceCube principal investigator.

In a paper published in the April 19 issue of the journal Nature, the IceCube collaboration describes a search for neutrinos emitted from 300 gamma ray bursts observed between May 2008 and April 2010 in coincidence with the SWIFT and Fermi satellites.

Surprisingly, the scientists found no neutrinos--a result that contradicts 15 years of predictions and challenges the theory that gamma-ray bursts produce the highest energy cosmic rays.

"The result of this neutrino search is significant because for the first time we have an instrument with sufficient sensitivity to open a new window on cosmic ray production and the interior processes of GRBs," said Greg Sullivan, a physicist at the University of Maryland and IceCube spokesman.

"The unexpected absence of neutrinos from GRBs has forced a re-evaluation of the theory for production of cosmic rays and neutrinos in a GRB fireball and possibly the theory that high-energy cosmic rays are generated in fireballs," he said.

IceCube observes neutrinos by detecting the faint blue light produced in neutrino interactions in ice. Neutrinos are of a ghostly nature; they can easily travel through people, walls, or the planet Earth. To compensate for the antisocial nature of neutrinos and detect their rare interactions, IceCube is built on an enormous scale. One cubic kilometer of glacial ice, enough to fit the great pyramid of Giza 400 times, is instrumented with 5,160 optical sensors embedded up to 2.5 kilometers deep in the ice.

GRBs, the universe's most powerful explosions, are usually first observed by satellites using X-rays and/or gamma rays. GRBs are seen about once per day, and are so bright that they can be seen from half way across the visible Universe. The explosions usually last only a few seconds, and during this brief time they can outshine everything else in the universe.

The IceCube Neutrino Observatory was built under a National Science Foundation (NSF) Major Research Equipment and Facilities Construction grant, with assistance from partner funding agencies around the world.

NSF continues to support the project with a Maintenance and Operations grant co-funded by the Division of Antarctic Sciences and the Division of Physics. IceCube construction was finished in December 2010. A collaboration of 250 physicists and engineers from the United States, Germany, Sweden, Belgium, Switzerland, Japan, Canada, New Zealand, Australia and Barbados operate the observatory.

"Building the IceCube Neutrino Observatory at the geographic South Pole was a major effort made possible through many collaborating institutions and the U.S. Antarctic Program," said Scott Borg, division director for Antarctic Sciences in NSF's Office of Polar Programs. "The IceCube Collaboration has been busy analyzing data and the finding published in Nature is an early and significant, result. We are pleased with this achievement but we also anticipate many more important discoveries to follow."

NSF, an independent U.S. government agency, manages the U.S. Antarctic Program, through which it coordinates all U.S. scientific research on the southernmost continent and aboard ships in the Southern Ocean as well as related logistics support.

Improved theoretical understanding and continued data collection from the complete and fully calibrated IceCube detector will help scientists better uncover the mystery of cosmic ray production.