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1

ARPA-E 2011 Keynote: Ray Mabus, Secretary of the Navy | Department of  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Ray Mabus, Secretary of the Navy Ray Mabus, Secretary of the Navy ARPA-E 2011 Keynote: Ray Mabus, Secretary of the Navy Addthis Description Secretary of the Navy Ray Mabus addresses the 2nd annual ARPA-E Energy Innovation Summit on the Navy's fuel consumption and successful implementation of biofuels. Speakers Ray Mabus, Secretary of the Navy Duration 28:24 Topic Energy Policy Fuel Economy Energy Sources Emerging Technologies Credit Energy Department Video SECRETARY RAY MABUS: One of the things that has always amazed and gratified me is the talent of people who are willing to serve in government, willing to take less money, more trouble on behalf of their country. Every time we seem to need somebody, somebody good - you hope - steps forward. We have a great secretary of defense right now in Bob Gates, but we sure

2

ARPA-E 2011 Keynote: Ray Mabus, Secretary of the Navy | Department...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Mabus addresses the 2nd annual ARPA-E Energy Innovation Summit on the Navy's fuel consumption and successful implementation of biofuels. Speakers Ray Mabus, Secretary of the...

3

ARPA-E 2011 Keynote: Ray Mabus, Secretary of the Navy | Department...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Pledge? Conversation on the Future of the Wind Industry Science Lecture: Talking the Higgs Boson with Dr. Joseph Incandela Bill Gates and Deputy Secretary Poneman Discuss the...

4

The Turn-on of LCLS: the X-Ray Free Electron Laser at SLAC ( Keynote - 2011 JGI User Meeting)  

Science Conference Proceedings (OSTI)

The U.S. Department of Energy Joint Genome Institute (JGI) invited scientists interested in the application of genomics to bioenergy and environmental issues, as well as all current and prospective users and collaborators, to attend the annual DOE JGI Genomics of Energy & Environment Meeting held March 22-24, 2011 in Walnut Creek, Calif. The emphasis of this meeting was on the genomics of renewable energy strategies, carbon cycling, environmental gene discovery, and engineering of fuel-producing organisms. The meeting features presentations by leading scientists advancing these topics. SLAC National Laboratory Director Persis Drell gives a keynote talk on "The Turn-on of LCLS: the X-Ray Free-Electron Laser at SLAC" at the 6th Genomics of Energy & Environment Meeting on March 22, 2011

Drell, Persis [SLAC Director

2011-03-22T23:59:59.000Z

5

Oven | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Ray Mabus, Secretary of the Navy Electrofuels:...

6

Seven Traffic Signals in Two Minutes | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Ray Mabus, Secretary of the Navy Electrofuels:...

7

How Energy Efficiency is Adding Jobs in St. Paul, Minnesota ...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Ray Mabus, Secretary of the Navy Electrofuels:...

8

Charging Up in King County, Washington | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Ray Mabus, Secretary of the Navy Electrofuels:...

9

Demoing the Modified TALON Robot | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Ray Mabus, Secretary of the Navy Electrofuels:...

10

Cliff | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Ray Mabus, Secretary of the Navy Electrofuels:...

11

Conversation on the Future of the Wind Industry | Department...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Ray Mabus, Secretary of the Navy Electrofuels:...

12

Joining the Obama Administration | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Ray Mabus, Secretary of the Navy Electrofuels:...

13

Retrofitting the Streetlights in Boise, Idaho | Department of...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Ray Mabus, Secretary of the Navy Electrofuels:...

14

Cathy Zoi on Weatherization | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Dr. Arun Majumdar ARPA-E 2011 Keynote: Ray Mabus,...

15

Sec. Chu Announces the First Auto Loans for Advanced Technologies...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Dr. Arun Majumdar ARPA-E 2011 Keynote: Ray Mabus,...

16

Energy 101: Home Energy Assessment | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Dr. Arun Majumdar ARPA-E 2011 Keynote: Ray Mabus,...

17

Home Energy Assessments | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Dr. Arun Majumdar ARPA-E 2011 Keynote: Ray Mabus,...

18

Matt Rogers on AES Energy Storage | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Dr. Arun Majumdar ARPA-E 2011 Keynote: Ray Mabus,...

19

Energy 101: Cool Roofs | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Dr. Arun Majumdar ARPA-E 2011 Keynote: Ray Mabus,...

20

Faces of the Recovery Act: Sun Catalytix | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Dr. Arun Majumdar ARPA-E 2011 Keynote: Ray Mabus,...

Note: This page contains sample records for the topic "keynote ray mabus" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Boys of Coshocton: Part One | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Dr. Arun Majumdar ARPA-E 2011 Keynote: Ray Mabus,...

22

Backstage at the Daily Show | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Dr. Arun Majumdar ARPA-E 2011 Keynote: Ray Mabus,...

23

Weatherizing Wilkes-Barre | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Dr. Arun Majumdar ARPA-E 2011 Keynote: Ray Mabus,...

24

Secretary Chu and the 'Sputnik Moment' | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Dr. Arun Majumdar ARPA-E 2011 Keynote: Ray Mabus,...

25

Secretary Chu Travels to India | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Dr. Arun Majumdar ARPA-E 2011 Keynote: Ray Mabus,...

26

Electrofuels: More Efficient Than Photosynthesis | Department...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Dr. Arun Majumdar ARPA-E 2011 Keynote: Ray Mabus,...

27

Faces of the Recovery Act: 1366 Technologies | Department of...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Dr. Arun Majumdar ARPA-E 2011 Keynote: Ray Mabus,...

28

Recovery Act update from Sr. Advisor Matt Rogers -- End of Obligations...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Dr. Arun Majumdar ARPA-E 2011 Keynote: Ray Mabus,...

29

Cathy Zoi on the new Home Energy Score pilot program | Department...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Dr. Arun Majumdar ARPA-E 2011 Keynote: Ray Mabus,...

30

Linac Coherent Light Source Overview | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Dr. Arun Majumdar ARPA-E 2011 Keynote: Ray Mabus,...

31

Re-Building Greensburg | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Dr. Arun Majumdar ARPA-E 2011 Keynote: Ray Mabus,...

32

Why Cool Roofs? | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Dr. Arun Majumdar ARPA-E 2011 Keynote: Ray Mabus,...

33

The Weatherization Training program at Pennsylvania College ...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Dr. Arun Majumdar ARPA-E 2011 Keynote: Ray Mabus,...

34

President Barack Obama at UN Climate Change Summit | Department...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Dr. Arun Majumdar ARPA-E 2011 Keynote: Ray Mabus,...

35

Faces of the Recovery Act: National Weatherization Conference...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Dr. Arun Majumdar ARPA-E 2011 Keynote: Ray Mabus,...

36

200,000 homes weatherized under the Recovery Act | Department...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Dr. Arun Majumdar ARPA-E 2011 Keynote: Ray Mabus,...

37

Solar Decathlon Update from Secretary Chu | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Dr. Arun Majumdar ARPA-E 2011 Keynote: Ray Mabus,...

38

Recovery Act Milestones | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Dr. Arun Majumdar ARPA-E 2011 Keynote: Ray Mabus,...

39

Profiling 1366 Technologies: One Year Later | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Dr. Arun Majumdar ARPA-E 2011 Keynote: Ray Mabus,...

40

The Kill-a-Watt Competition at University of Central Florida...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Dr. Arun Majumdar ARPA-E 2011 Keynote: Ray Mabus,...

Note: This page contains sample records for the topic "keynote ray mabus" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Faces of the Recovery Act: The Impact of Smart Grid | Department...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Dr. Arun Majumdar ARPA-E 2011 Keynote: Ray Mabus,...

42

Boys of Coshocton: Part Two | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Dr. Arun Majumdar ARPA-E 2011 Keynote: Ray Mabus,...

43

Faces of the Recovery Act: Jobs at Savannah River Site | Department...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Dr. Arun Majumdar ARPA-E 2011 Keynote: Ray Mabus,...

44

The Climate Challenge... and What's at Stake | Department of...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Dr. Arun Majumdar ARPA-E 2011 Keynote: Ray Mabus,...

45

Weatherizing America | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Dr. Arun Majumdar ARPA-E 2011 Keynote: Ray Mabus,...

46

Home Weatherization Visit | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Dr. Arun Majumdar ARPA-E 2011 Keynote: Ray Mabus,...

47

Faces of the Recovery Act: Johnson Controls Inc. | Department...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security & Safety -Emergency Response & Procedures or Search Energy.gov Search Clear Filters All Videos ARPA-E 2011 Keynote: Dr. Arun Majumdar ARPA-E 2011 Keynote: Ray Mabus,...

48

Keynote: Implementing New Technology in Metallurgical Processes  

Science Conference Proceedings (OSTI)

Presentation Title, Keynote: Implementing New Technology in Metallurgical Processes: Building ... DRI-based Continuous Steelmaking: From Theory to Practice.

49

A New Biofuels Technology Blooms in Iowa | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

ARPA-E 2011 Keynote: Ray Mabus, Secretary of the Navy Electrofuels: More Efficient Than Photosynthesis Profiling 1366 Technologies: One Year Later How ARPA-e is "Winning the...

50

The Future of Biofuels | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

ARPA-E 2011 Keynote: Ray Mabus, Secretary of the Navy Electrofuels: More Efficient Than Photosynthesis Profiling 1366 Technologies: One Year Later How ARPA-e is "Winning the...

51

Keynote Address: Update on Environmental Management  

Energy.gov (U.S. Department of Energy (DOE))

Keynote presentation made by David G. Huizenga for the NTSF annual meeting held from May 14-16, 2013 in Buffalo, NY.

52

Keynote Address by David Sandalow, Assistant Secretary of Energy...  

NLE Websites -- All DOE Office Websites (Extended Search)

Keynote Address by David Sandalow, Assistant Secretary of Energy for Policy and International Affiars, at the Technology and Rare Earth Metals Conference 2010 Keynote Address by...

53

Clean Energy Action Star Governor Schwarzenegger to Keynote ARPA...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Action Star Governor Schwarzenegger to Keynote ARPA-E Energy Innovation Summit Clean Energy Action Star Governor Schwarzenegger to Keynote ARPA-E Energy Innovation Summit February...

54

Secretary Chu to Deliver Keynote on EV Everywhere Grand Challenge...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

to Deliver Keynote on EV Everywhere Grand Challenge at Washington Auto Show Secretary Chu to Deliver Keynote on EV Everywhere Grand Challenge at Washington Auto Show January 30,...

55

KEYNOTE  

Science Conference Proceedings (OSTI)

... POLAND Page 2. Page 3. ... Poland and Hungary - largest consumers among the CITs * the Russian Federation - the only producer. ...

2011-11-17T23:59:59.000Z

56

Opening Keynote at Cloud Computing Forum & Workshop V  

Science Conference Proceedings (OSTI)

Opening Keynote at Cloud Computing Forum & Workshop V, Department of Commerce, Washington, DC, June 5, 2012, Dr. Patrick Gallagher ...

2013-07-08T23:59:59.000Z

57

MCS researchers give keynote addresses at HPCS 2013 | Argonne...  

NLE Websites -- All DOE Office Websites (Extended Search)

Franck Cappello gave keynote addresses at the international conference on High Performance Computing and Simulation (HPCS 2103) in Helsinki, Finland, July 1-5, 2013. Foster, an...

58

Snir gives keynote address at distributed computing conference | Argonne  

NLE Websites -- All DOE Office Websites (Extended Search)

Snir gives keynote address at distributed computing conference Snir gives keynote address at distributed computing conference August 14, 2013 Tweet EmailPrint Marc Snir, director of Argonne's Mathematics and Computer Science Division and Argonne Distinguished Fellow, delivered a keynote address at the joint PODC/SPAA symposium held in Montreal, Canada, July 22-24, 2013. The PODC (Principles of Distributed Computing) symposium was collocated this year with SPAA (Symposium on Parallelism in Algorithms and Architectures). Both annual conferences are sponsored by the Association for Computer Machinery. Snir's presentation, titled "Supercomputing: Technical Evolution and Programming Models," began with a description of punctuated equilibrium and three technological (r)evolutionary developments in high-performance

59

Synthetic Biology for Advanced Fuels (Opening Keynote Address - 2010 JGI User Meeting)  

DOE Green Energy (OSTI)

Jay Keasling, CEO of the Joint BioEnergy Institute, delivers the opening keynote on March 24, 2010 at the 5th Annual DOE JGI User Meeting

Keasling, Jay

2010-03-24T23:59:59.000Z

60

Assistant Secretary Patricia Hoffman to Deliver Keynote Address at IEEE PES  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Assistant Secretary Patricia Hoffman to Deliver Keynote Address at Assistant Secretary Patricia Hoffman to Deliver Keynote Address at IEEE PES Conference on Innovative Smart Grid Technologies Assistant Secretary Patricia Hoffman to Deliver Keynote Address at IEEE PES Conference on Innovative Smart Grid Technologies January 25, 2013 - 3:10pm Addthis Assistant Secretary Patricia Hoffman will give the keynote address at the 4th annual IEEE PES Conference on Innovative Smart Grid Technologies (ISGT 2013) on Monday, February 25. The conference, which will be held from February 24 through February 27 in Washington, DC, is a forum to discuss state-of-the-art innovations in smart grid technologies. The event will feature tutorials, panel sessions and paper presentations by international experts. Other keynote speakers will include Mark Wyatt, Vice President

Note: This page contains sample records for the topic "keynote ray mabus" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Clean Energy Action Star Governor Schwarzenegger to Keynote ARPA-E Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Clean Energy Action Star Governor Schwarzenegger to Keynote ARPA-E Clean Energy Action Star Governor Schwarzenegger to Keynote ARPA-E Energy Innovation Summit Clean Energy Action Star Governor Schwarzenegger to Keynote ARPA-E Energy Innovation Summit February 22, 2011 - 12:20pm Addthis Clean Energy Action Star Governor Schwarzenegger to Keynote ARPA-E Energy Innovation Summit Ginny Simmons Ginny Simmons Former Managing Editor for Energy.gov, Office of Public Affairs I doubt I was the only one thrilled to hear that former California Governor Arnold Schwarzenegger will keynote the second annual ARPA-E Energy Innovation Summit at the end of this month.
 On top of being the former governor of the State of California and one of the biggest movie stars of all time, Arnold Schwarzenegger is also credited with having played a pivotal role in leading the state of California toward

62

Assistant Secretary Patricia Hoffman to Deliver Keynote Address at IEEE PES  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Patricia Hoffman to Deliver Keynote Address at Patricia Hoffman to Deliver Keynote Address at IEEE PES Conference on Innovative Smart Grid Technologies Assistant Secretary Patricia Hoffman to Deliver Keynote Address at IEEE PES Conference on Innovative Smart Grid Technologies January 25, 2013 - 3:10pm Addthis Assistant Secretary Patricia Hoffman will give the keynote address at the 4th annual IEEE PES Conference on Innovative Smart Grid Technologies (ISGT 2013) on Monday, February 25. The conference, which will be held from February 24 through February 27 in Washington, DC, is a forum to discuss state-of-the-art innovations in smart grid technologies. The event will feature tutorials, panel sessions and paper presentations by international experts. Other keynote speakers will include Mark Wyatt, Vice President

63

Clean Energy Action Star Governor Schwarzenegger to Keynote ARPA-E Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Energy Action Star Governor Schwarzenegger to Keynote ARPA-E Energy Action Star Governor Schwarzenegger to Keynote ARPA-E Energy Innovation Summit Clean Energy Action Star Governor Schwarzenegger to Keynote ARPA-E Energy Innovation Summit February 22, 2011 - 12:20pm Addthis Clean Energy Action Star Governor Schwarzenegger to Keynote ARPA-E Energy Innovation Summit Ginny Simmons Ginny Simmons Former Managing Editor for Energy.gov, Office of Public Affairs I doubt I was the only one thrilled to hear that former California Governor Arnold Schwarzenegger will keynote the second annual ARPA-E Energy Innovation Summit at the end of this month.
 On top of being the former governor of the State of California and one of the biggest movie stars of all time, Arnold Schwarzenegger is also credited with having played a pivotal role in leading the state of California toward

64

Secretary Chu to Deliver Keynote on EV Everywhere Grand Challenge at  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

to Deliver Keynote on EV Everywhere Grand Challenge to Deliver Keynote on EV Everywhere Grand Challenge at Washington Auto Show Secretary Chu to Deliver Keynote on EV Everywhere Grand Challenge at Washington Auto Show January 30, 2013 - 1:37pm Addthis NEWS MEDIA CONTACT (202) 586-4940 WASHINGTON - Tomorrow, Thursday, January 31, 2013, Secretary Chu will deliver the government keynote address at the Washington Auto Show's Public Policy Day. His remarks will focus on the Energy Department's EV Everywhere Grand Challenge, including progress to date and a new initiative to strengthen American leadership in this rapidly growing global industry. Launched by President Obama in March 2012, EV-Everywhere is the second in a series of Energy Department "Clean Energy Grand Challenges" aimed at addressing the most pressing energy challenges of our time. The EV

65

Keynote Presentation: Genome Beat (JGI Seventh Annual User Meeting 2012: Genomics of Energy and Environment)  

Science Conference Proceedings (OSTI)

Carl Zimmer, a reporter for the New York Times, speaks on "The Genome Beat," the opening keynote presentation at the JGI User 7th Annual Genomics of Energy & Environment Meeting on March 22, 2012 in Walnut Creek, Calif

Zimmer, Carl [New York Times

2012-03-20T23:59:59.000Z

66

Secretary Chu to Give Keynote Address at World Forum on Enterprise and the  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

to Give Keynote Address at World Forum on Enterprise to Give Keynote Address at World Forum on Enterprise and the Environment Secretary Chu to Give Keynote Address at World Forum on Enterprise and the Environment June 25, 2010 - 12:00am Addthis Washington, DC - On Sunday, June 27th, U.S. Energy Secretary Steven Chu will travel to the United Kingdom to deliver the keynote address at the World Forum on Enterprise and the Environment, hosted by the Oxford University Smith School of Enterprise and the Environment. This year's forum will focus on "Low Carbon Mobility: Land; Sea and Air." On Monday, Secretary Chu will be attending diplomatic meetings focused on solving our shared energy and climate challenges. Following the morning meetings, Secretary Chu will travel to Houston as part of his ongoing work

67

Energy Secretary Chu to Keynote World Renewable Energy Forum in Denver |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

to Keynote World Renewable Energy Forum in to Keynote World Renewable Energy Forum in Denver Energy Secretary Chu to Keynote World Renewable Energy Forum in Denver May 16, 2012 - 1:13pm Addthis News Media Contact (202) 386-4940 WASHINGTON - Today, Wednesday, May 16, 2012, U.S. Energy Secretary Steven Chu will deliver a keynote address at the World Renewable Energy Forum in Denver, Colorado, where he will highlight the economic opportunities in the clean energy economy as well as the Obama Administration's commitments to strengthening U.S. leadership in the global clean energy race and helping American clean energy companies continue to create jobs and reduce our dependence on foreign oil. Following his remarks, Secretary Chu will tour the Exhibit Hall and participate in a media availability with Metro Denver Economic Development

68

Secretary Chu to Give Keynote Address at World Forum on Enterprise and the  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Secretary Chu to Give Keynote Address at World Forum on Enterprise Secretary Chu to Give Keynote Address at World Forum on Enterprise and the Environment Secretary Chu to Give Keynote Address at World Forum on Enterprise and the Environment June 25, 2010 - 12:00am Addthis Washington, DC - On Sunday, June 27th, U.S. Energy Secretary Steven Chu will travel to the United Kingdom to deliver the keynote address at the World Forum on Enterprise and the Environment, hosted by the Oxford University Smith School of Enterprise and the Environment. This year's forum will focus on "Low Carbon Mobility: Land; Sea and Air." On Monday, Secretary Chu will be attending diplomatic meetings focused on solving our shared energy and climate challenges. Following the morning meetings, Secretary Chu will travel to Houston as part of his ongoing work

69

Videos | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Energy 101: Energy Efficient Data Centers Energy 101: Energy Efficient Data Centers Energy 101: Daylighting Solar Smarter Faster Seven Traffic Signals in Two Minutes It Starts with Science... Demoing the Modified TALON Robot Retrofitting the Streetlights in Boise, Idaho Cutting Electricity Costs in Miami-Dade County, Florida How Energy Efficiency is Adding Jobs in St. Paul, Minnesota Charging Up in King County, Washington ARPA-E 2011 Keynote: Secretary Steven Chu Slides SlideShare. Present yourself. Upload Login or Signup Go Pro ARPA-E Energy Innovation Summit 2011 Keynote Presentation: Secretary Steven Chu ARPA-E 2011 Keynote: Dr. Arun Majumdar ARPA-E 2011 Keynote: Ray Mabus, Secretary of the Navy Electrofuels: More Efficient Than Photosynthesis Profiling 1366 Technologies: One Year Later How ARPA-e is "Winning the Future"

70

KEYNOTE SPEAKER: Gary Petersen, Director of Transportation, General Mills 8th Annual Freight and Logistics Symposium  

E-Print Network (OSTI)

the future of the freight industry--from trucking to rail, air, and marine transport--at the 8th Annual included the changing landscape of transportation, public- and private-sector views of the futureKEYNOTE SPEAKER: Gary Petersen, Director of Transportation, General Mills 8th Annual Freight

Minnesota, University of

71

Towards the Perfect Genome Sequence (Opening Keynote) ( 7th Annual SFAF Meeting, 2012)  

Science Conference Proceedings (OSTI)

George Weinstock, associate director at the Genome Institute at Washington University, delivered the opening keynote "Towards the Perfect Genome Sequence" at the 2012 Sequencing, Finishing, Analysis in the Future Meeting held June 5-7, 2012 in Santa Fe, New Mexico.

Weinstock, George [Washington University

2012-06-01T23:59:59.000Z

72

ARPA-E 2011 Keynote: Secretary Steven Chu | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Secretary Steven Chu Secretary Steven Chu ARPA-E 2011 Keynote: Secretary Steven Chu Addthis Description US Department of Energy Secretary, Steven Chu, discusses the big picture of how the United States uses energy and why innovation in clean technology is key to 'Winning the Future'. Speakers Secretary Steven Chu Duration 20:47 Topic Energy Sources Oil Energy Economy Energy Policy Credit Energy Department Video Slides SlideShare. Present yourself. Upload Login or Signup Go Pro ARPA-E Energy Innovation Summit 2011 Keynote Presentation: Secretary Steven Chu SECRETARY STEVEN CHU: Thank you, room. A lot of people here. That's a good sign. As long as the attendance keeps rising over the coming years, we will be very, very happy. Let me talk about what we're facing. This is a recent history -

73

ARPA-E 2011 Keynote: Dr. Arun Majumdar | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Dr. Arun Majumdar Dr. Arun Majumdar ARPA-E 2011 Keynote: Dr. Arun Majumdar Addthis Description Dr. Arun Majumdar, Director of the Advanced Research Projects Agency for Energy (ARPA-E) offers a glimpse into the future of energy innovation at the ARPA-E Energy Innovation Summit during his Keynote Address. Speakers Arun Majumdar Duration 23:50 Topic Energy Economy Innovation ARPA-E Summit Emerging Technologies Credit Energy Department Video ARUN MAJUMDAR: My life story has been described in gory detail. (Laughter.) But it's great pleasure to be here. Let me start by telling you my story of ARPA-E. When I came here about a year-and-a-half ago and asked to lead this agency, I thought it was an absolutely daunting task. I'd never been in Washington and here I'm trying to start a couple of agencies.

74

"Investing in NNSA is an Investment in the Tennessee Valley," Keynote  

National Nuclear Security Administration (NNSA)

"Investing in NNSA is an Investment in the Tennessee Valley," Keynote "Investing in NNSA is an Investment in the Tennessee Valley," Keynote Address to the 2011 TVC National Technology Summit by Administrator Thomas P. D'Agostino | National Nuclear Security Administration Our Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency Response Recapitalizing Our Infrastructure Continuing Management Reform Countering Nuclear Terrorism About Us Our Programs Our History Who We Are Our Leadership Our Locations Budget Our Operations Media Room Congressional Testimony Fact Sheets Newsletters Press Releases Speeches Events Social Media Video Gallery Photo Gallery NNSA Archive Federal Employment Apply for Our Jobs Our Jobs Working at NNSA Blog Home > Media Room > Speeches > "Investing in NNSA is an Investment in ...

75

Keynote Address to the American Council on Renewable Energy | Department of  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Keynote Address to the American Council on Renewable Energy Keynote Address to the American Council on Renewable Energy Keynote Address to the American Council on Renewable Energy June 20, 2007 - 2:07pm Addthis Remarks Prepared for Energy Secretary Samuel W. Bodman Thank you, Michael, for that introduction and thank you all for coming. It is good to be in New York, back among the financial community. For those of you who don't know, when I left M.I.T - where I taught chemical engineering - to enter the business world I started out as a venture capitalist. It's an industry, though we didn't call it that then, I have now been associated with for 45 years. I say this only to let you know I understand the challenges before you. Had my life taken a different course, had I not had the blazing insight that I should go to Washington to help run the government, I might be

76

2012 ARPA-E Energy Innovation Summit Keynote Presentation (Arun Majumdar)  

Science Conference Proceedings (OSTI)

The third annual ARPA-E Energy Innovation Summit was held in Washington D.C. in February, 2012. The event brought together key players from across the energy ecosystem - researchers, entrepreneurs, investors, corporate executives, and government officials - to share ideas for developing and deploying the next generation of energy technologies. Director of ARPA-E, Arun Majumdar, gave the final keynote address for Tuesday, February 28th. He discussed APRA-E's role in meeting 21st century energy needs with American innovation.

Majumdar, Arun (ARPA-E Director)

2012-02-28T23:59:59.000Z

77

Celebration of DOE's 35th Anniversary and the Secretary of Energy's Honor Awards, Keynote Address: Energy Secretary, Dr. Steven Chu  

Science Conference Proceedings (OSTI)

Dr. Steven Chu gives a keynote address marking the thirty-fifth anniversary of the Department of Energy (DOE). He highlights outstanding achievements of the Department and its scientists. Several of the Department's many Nobel Prize winners over the years are mentioned.

Chu, Steven (U.S. Energy Secretary)

2012-10-04T23:59:59.000Z

78

Keynote Address  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Update on Environmental Management Update on Environmental Management Alice Williams Associate Principal Deputy Assistant Secretary Office of Environmental Management National Transportation Stakeholders Forum MAY 16, 2012 KNOXVILLE, TN www.em.doe.gov 2 "Complete the safe cleanup of the environmental legacy brought about from five decades of nuclear weapons development, production, and Government-sponsored nuclear energy research"  From a legacy of weapons production to the world's largest environmental cleanup program  Operating in the world's most complex regulatory environment  EM cleanup enables DOE to

79

Keynote Address  

Energy.gov (U.S. Department of Energy (DOE))

An overview and update on Environmental Management given by Alice Williams, Associate Principal Deputy Assistant Secretary of the Office of Environmental Management.

80

keynote papers  

Science Conference Proceedings (OSTI)

Combustion Synthesis of Fe-TiC and Fe-(W,Ti)C Composites [pp. 1,209-1,215] A. Saidi, M. Golozar, J.V. Wood, and J.L.F. Kellie. Structural Change of Y2O3...

Note: This page contains sample records for the topic "keynote ray mabus" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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81

Keynote Session  

Science Conference Proceedings (OSTI)

Unconventional approaches must therefore be developed and employed to achieve design success, among them parametric configuration definition, automated...

82

2012 ARPA-E Energy Innovation Summit Keynote Presentation (Secretary of Energy Steven Chu)  

Science Conference Proceedings (OSTI)

The third annual ARPA-E Energy Innovation Summit was held in Washington D.C. in February, 2012. The event brought together key players from across the energy ecosystem - researchers, entrepreneurs, investors, corporate executives, and government officials - to share ideas for developing and deploying the next generation of energy technologies. Dr. Steven Chu, Energy Secretary, gave the first keynote presentation of the day. He discusses how President Obama's 'all-of-the-above' approach to energy will help the Unites States solve 21st century global energy challenges and maintain its leadership as an exporter of energy technology. Secretary of Energy Steven Chu highlighted our vulnerability to price fluctuations in the fuel markets, most recently to oil and gasoline, as well as our inability to drill our way out of the problem. Secretary Chu made the case for leveraging energy innovation in order to reduce our exposure to oil price fluctuations and improve the U.S.'s economic competitiveness.

Chu, Steven (U.S. Department of Energy Secretary)

2012-02-28T23:59:59.000Z

83

The Gulf Oil Spill: Ecogenomics and Ecoresilience (Keynote - 2011 JGI User Meeting)  

Science Conference Proceedings (OSTI)

The U.S. Department of Energy Joint Genome Institute (JGI) invited scientists interested in the application of genomics to bioenergy and environmental issues, as well as all current and prospective users and collaborators, to attend the annual DOE JGI Genomics of Energy & Environment Meeting held March 22-24, 2011 in Walnut Creek, Calif. The emphasis of this meeting was on the genomics of renewable energy strategies, carbon cycling, environmental gene discovery, and engineering of fuel-producing organisms. The meeting features presentations by leading scientists advancing these topics. Berkeley Lab microbial ecologist Terry Hazen delivers a keynote on "The Gulf Oil Spill: Ecogenomics and Ecoresilience" at the 6th Genomics of Energy & Environment Meeting on March 22, 2011.

Hazen, Terry [LBNL

2011-03-22T23:59:59.000Z

84

2012 ARPA-E Energy Innovation Summit Keynote Presentation (Bill Clinton, 42nd President of the United States)  

Science Conference Proceedings (OSTI)

The third annual ARPA-E Energy Innovation Summit was held in Washington D.C. in February, 2012. The event brought together key players from across the energy ecosystem - researchers, entrepreneurs, investors, corporate executives, and government officials - to share ideas for developing and deploying the next generation of energy technologies. Former President Bill Clinton, the 42nd President of the United States, gave the final keynote address of the 2012 Summit on February 29. He addressed the importance of government investment in research that will help move the world toward a cleaner and more secure energy future.

Clinton, William J. (Bill) (42nd President of the United States)

2012-02-29T23:59:59.000Z

85

Closing Keynote Presentation on the Genomics of Energy and the Environment (JGI Seventh Annual User Meeting 2012: Genomics of Energy and Environment)  

Science Conference Proceedings (OSTI)

Steve Benner, a distinguished chemist at the Foundation for Applied Molecular Evolution, Westheimer Institute of Science and Technology, provides the closing keynote address for the JGI 7th Annual Users Meeting: Genomics of Energy & Environment Meeting on March 22, 2012 in Walnut Creek, California.

Benner, Stephen [Foundation for Applied Molecular Evolution, Westheimer Institute of Science and Technology

2012-03-22T23:59:59.000Z

86

Energy Frontier Research Centers: Helping Win the Energy Innovation Race (2011 EFRC Summit Keynote Address, Secretary of Energy Chu)  

Science Conference Proceedings (OSTI)

Secretary of Energy Steven Chu gave the keynote address at the 2011 EFRC Summit and Forum. In his talk, Secretary Chu highlighted the need to "unleash America's science and research community" to achieve energy breakthroughs. The 2011 EFRC Summit and Forum brought together the EFRC community and science and policy leaders from universities, national laboratories, industry and government to discuss "Science for our Nation's Energy Future." In August 2009, the Office of Science established 46 Energy Frontier Research Centers. The EFRCs are collaborative research efforts intended to accelerate high-risk, high-reward fundamental research, the scientific basis for transformative energy technologies of the future. These Centers involve universities, national laboratories, nonprofit organizations, and for-profit firms, singly or in partnerships, selected by scientific peer review. They are funded at $2 to $5 million per year for a total planned DOE commitment of $777 million over the initial five-year award period, pending Congressional appropriations. These integrated, multi-investigator Centers are conducting fundamental research focusing on one or more of several grand challenges and use-inspired basic research needs recently identified in major strategic planning efforts by the scientific community. The purpose of the EFRCs is to integrate the talents and expertise of leading scientists in a setting designed to accelerate research that transforms the future of energy and the environment.

Chu, Steven (DOE Secretary of Energy)

2011-05-25T23:59:59.000Z

87

Energy Sources | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

March 17, 2011 March 17, 2011 A basic overview of GreenFire's process to convert CO2 into electricity. | Photo courtesy of GreenFire. Innovative Geothermal Startup Will Put Carbon Dioxide To Good Use GreenFire Energy began work to demonstrate a process that would use CO2 to harness geothermal energy to make electricity. What is more, the technology has the potential to add carbon sequestration - not to mention reduced water consumption - to the benefits already associated with geothermal power. March 2, 2011 ARPA-E 2011 Keynote: Ray Mabus, Secretary of the Navy February 27, 2011 How ARPA-e is "Winning the Future" February 4, 2011 Vintage DOE: Wind We're digging through the Department's video archives. Check out this 1980 clip that outlines the beginnings of the Department's focus on wind as

88

Page not found | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

61 - 21370 of 26,764 results. 61 - 21370 of 26,764 results. Download FAQS Reference Guide - Electrical Systems and Safety Oversight This reference guide addresses the competency statements in the August 2007 edition of DOE-STD-1170-2007, Electrical Systems and Safety Oversight Functional Area Qualification Standard. http://energy.gov/hss/downloads/faqs-reference-guide-electrical-systems-and-safety-oversight Download Q&A: Cybersecurity Issues and Requirements, December 11, 2009 Questions and Answers related to the presentation on issues and requirements for cybersecurity plans for Smart Grid Investment Grants for the American Recovery and Reinvestment Act http://energy.gov/oe/downloads/qa-cybersecurity-issues-and-requirements-december-11-2009 Video ARPA-E 2011 Keynote: Ray Mabus, Secretary of the Navy

89

Keynote: Jess Villasante  

Science Conference Proceedings (OSTI)

There is growing momentum around Cloud Computing among technology providers, end users, and academia. It is considered as a key theme for both the research constituency itself and for policy makers. Even though Cloud computing is a commercial reality ... Keywords: cloud computing, European research

2010-03-01T23:59:59.000Z

90

Keynote Presentation at RAPID 2013  

Science Conference Proceedings (OSTI)

... of technology innovations will be integrally linked to production processes to ... and he tasked the Departments of Defense and Energy to use ...

2013-07-02T23:59:59.000Z

91

Keynote Address Daniel B. Poneman  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Expert Laura Turner Seydel is a nationally recognized environmental advocate and eco-living expert committed to the education, conservation and efforts working to continuously...

92

Gifi Goes Logistic: SCASA Keynote  

E-Print Network (OSTI)

multiple deleted Smearing B-spline (order 2) Interactivespline coding Indicator Matrices and Indicator Super-matrix Missing Data a ? b ?

de Leeuw, Jan

2005-01-01T23:59:59.000Z

93

2002 TMS Annual Meeting & Exhibition: Keynote Presentation ...  

Science Conference Proceedings (OSTI)

His personal research interests include conduction mechanisms in ceramic ... biomimetic formation of new materials, non-thermal plasma emission control, and ...

94

2013 Aluminum Keynote Session - Programmaster.org  

Science Conference Proceedings (OSTI)

Mar 4, 2013 ... Arguably the biggest change affecting the U.S. downstream energy market is the rapid development of shale oil supply. Shale oil production...

95

Gifi Goes Logistic: SCASA 2005 Keynote  

E-Print Network (OSTI)

multiple deleted Smearing B-spline (order 2) Interactivespline coding Indicator Matrices and Indicator Super-matrix Missing Data a ? b ?

Jan de Leeuw

2011-01-01T23:59:59.000Z

96

Keynote: Haptic Human-Computer Interaction  

E-Print Network (OSTI)

Brewster,S.A. CHINZ 2003 (Dunedin, New Zealand) pp 3-4 Dept of Computing Science, University of Glasgow

Brewster, S.A.

97

The AIME/TMS Keynote Session  

Science Conference Proceedings (OSTI)

Alumax, led by Allen Born; Nucor, led by Ken Iverson; and Applied Materials, Inc., led by Dan Maydan are not only surviving, but prospering, by connecting...

98

Keynote Address at Manufacturing Innovation 2012  

Science Conference Proceedings (OSTI)

... Now, everyone here probably has a different definition that comes to mind ... increase their sales and stimulate growth while containing energy costs. ...

2012-05-23T23:59:59.000Z

99

2002 TMS Annual Meeting & Exhibition: Keynote Presentation  

Science Conference Proceedings (OSTI)

ENERGY ISSUES IN THE ALUMINUM INDUSTRY. Presenting the most informative overview yet on the Northwest energy crisis and its current and future impact...

100

X-Ray Topography  

Science Conference Proceedings (OSTI)

Sep 17, 2009 ... Stress Mapping Analysis by Ray Tracing (SMART): A New Technique ... technique of synchrotron X-ray topography, where a grid made out of...

Note: This page contains sample records for the topic "keynote ray mabus" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Ray tracing visualization toolkit  

Science Conference Proceedings (OSTI)

The Ray Tracing Visualization Toolkit (rtVTK) is a collection of programming and visualization tools supporting visual analysis of ray-based rendering algorithms. rtVTK leverages layered visualization within the spatial domain of computation, enabling ... Keywords: ray tracing, ray-based rendering, visualization

Christiaan Gribble; Jeremy Fisher; Daniel Eby; Ed Quigley; Gideon Ludwig

2012-03-01T23:59:59.000Z

102

Gamma-ray Astronomy  

E-Print Network (OSTI)

The relevance of gamma-ray astronomy to the search for the origin of the galactic and, to a lesser extent, the ultra-high-energy cosmic rays has long been recognised. The current renaissance in the TeV gamma-ray field has resulted in a wealth of new data on galactic and extragalactic particle accelerators, and almost all the new results in this field were presented at the recent International Cosmic Ray Conference (ICRC). Here I summarise the 175 papers submitted on the topic of gamma-ray astronomy to the 30th ICRC in Merida, Mexico in July 2007.

Hinton, Jim

2007-01-01T23:59:59.000Z

103

Gamma-ray Astronomy  

E-Print Network (OSTI)

The relevance of gamma-ray astronomy to the search for the origin of the galactic and, to a lesser extent, the ultra-high-energy cosmic rays has long been recognised. The current renaissance in the TeV gamma-ray field has resulted in a wealth of new data on galactic and extragalactic particle accelerators, and almost all the new results in this field were presented at the recent International Cosmic Ray Conference (ICRC). Here I summarise the 175 papers submitted on the topic of gamma-ray astronomy to the 30th ICRC in Merida, Mexico in July 2007.

Jim Hinton

2007-12-20T23:59:59.000Z

104

Gamma-Ray Bursts  

E-Print Network (OSTI)

Ultra-high-energy, >10^19 eV, cosmic-ray and high energy, ~10^14 eV, neutrino production in GRBs is discussed in the light of recent GRB and cosmic-ray observations. Emphasis is put on model predictions that can be tested with operating and planned cosmic-ray and neutrino detectors, and on the prospects of testing for neutrino properties.

E. Waxman

2000-04-11T23:59:59.000Z

105

GPU ray tracing  

Science Conference Proceedings (OSTI)

The NVIDIA OptiX ray tracing engine is a programmable system designed for NVIDIA GPUs and other highly parallel architectures. The OptiX engine builds on the key observation that most ray tracing algorithms can be implemented using a small ...

Steven G. Parker; Heiko Friedrich; David Luebke; Keith Morley; James Bigler; Jared Hoberock; David McAllister; Austin Robison; Andreas Dietrich; Greg Humphreys; Morgan McGuire; Martin Stich

2013-05-01T23:59:59.000Z

106

X-ray beamsplitter  

DOE Patents (OSTI)

An x-ray beamsplitter which splits an x-ray beam into two coherent parts by reflecting and transmitting some fraction of an incident beam has applications for x-ray interferometry, x-ray holography, x-ray beam manipulation, and x-ray laser cavity output couplers. The beamsplitter is formed of a wavelength selective multilayer thin film supported by a very thin x-ray transparent membrane. The beamsplitter resonantly transmits and reflects x-rays through thin film interference effects. A thin film is formed of 5-50 pairs of alternate Mo/Si layers with a period of 20-250 A. The support membrane is 10-200 nm of silicon nitride or boron nitride. The multilayer/support membrane structure is formed across a window in a substrate by first forming the structure on a solid substrate and then forming a window in the substrate to leave a free-standing structure over the window.

Ceglio, Natale M. (Livermore, CA); Stearns, Daniel S. (Mountain View, CA); Hawryluk, Andrew M. (Modesto, CA); Barbee, Jr., Troy W. (Palo Alto, CA)

1989-01-01T23:59:59.000Z

107

Gamma ray detector shield  

DOE Patents (OSTI)

A gamma ray detector shield comprised of a rigid, lead, cylindrical-shaped vessel having upper and lower portions with an pneumatically driven, sliding top assembly. Disposed inside the lead shield is a gamma ray scintillation crystal detector. Access to the gamma detector is through the sliding top assembly.

Ohlinger, R.D.; Humphrey, H.W.

1985-08-26T23:59:59.000Z

108

Gamma Ray Bursts  

E-Print Network (OSTI)

Gamma-ray bursts have been detected at photon energies up to tens of GeV. We review some recent developments in the X-ray to GeV photon phenomenology in the light of Swift and Fermi observations, and some of the theoretical models developed to explain them, with a view towards implications for C.T.A.

Peter Mszros

2012-04-09T23:59:59.000Z

109

X-ray generator  

DOE Patents (OSTI)

Apparatus and method for producing coherent secondary x-rays that are controlled as to direction by illuminating a mixture of high z and low z gases with an intense burst of primary x-rays. The primary x-rays are produced with a laser activated plasma, and these x-rays strip off the electrons of the high z atoms in the lasing medium, while the low z atoms retain their electrons. The neutral atoms transfer electrons to highly excited states of the highly striped high z ions giving an inverted population which produces the desired coherent x-rays. In one embodiment, a laser, light beam provides a laser spark that produces the intense burst of coherent x-rays that illuminates the mixture of high z and low z gases, whereby the high z atoms are stripped while the low z ones are not, giving the desired mixture of highly ionized and neutral atoms. To this end, the laser spark is produced by injecting a laser light beam, or a plurality of beams, into a first gas in a cylindrical container having an adjacent second gas layer co-axial therewith, the laser producing a plasma and the intense primary x-rays in the first gas, and the second gas containing the high and low atomic number elements for receiving the primary x-rays, whereupon the secondary x-rays are produced therein by stripping desired ions in a neutral gas and transfer of electrons to highly excited states of the stripped ions from the unionized atoms. Means for magnetically confining and stabilizing the plasma are disclosed for controlling the direction of the x-rays.

Dawson, John M. (Los Angeles, CA)

1976-01-01T23:59:59.000Z

110

X-Ray Observations of Gamma-Ray Burst Afterglows  

E-Print Network (OSTI)

The discovery by the BeppoSAX satellite of X-ray afterglow emission from the gamma-ray burst which occurred on 28 February 1997 produced a revolution in our knowledge of the gamma-ray burst phenomenon. Along with the discovery of X-ray afterglows, the optical afterglows of gamma-ray bursts were discovered and the distance issue was settled, at least for long $\\gamma$-ray bursts. The 30 year mystery of the gamma-ray burst phenomenon is now on the way to solution. Here I rewiew the observational status of the X-ray afterglow emission, its mean properties (detection rate, continuum spectra, line features, and light curves), and the X-ray constraints on theoretical models of gamma-ray bursters and their progenitors. I also discuss the early onset afterglow emission, the remaining questions, and the role of future X-ray afterglow observations.

Filippo Frontera

2004-06-25T23:59:59.000Z

111

Gamma Radiation & X-Rays  

NLE Websites -- All DOE Office Websites (Extended Search)

Gamma Radiation and X-Rays 1. Gamma radiation and X-rays are electromagnetic radiation like visible light, radio waves, and ultraviolet light. These electromagnetic radiations...

112

Gamma Ray Pulsars: Observations  

E-Print Network (OSTI)

High-energy gamma rays are a valuable tool for studying particle acceleration and radiation in the magnetospheres of energetic pulsars. The six or more pulsars seen by CGRO/EGRET show that: the light curves usually have double-peak structures (suggesting a broad cone of emission); gamma rays are frequently the dominant component of the radiated power; and all the spectra show evidence of a high-energy turnover. Unless a new pulsed component appears at higher energies, progress in gamma-ray pulsar studies will be greatest in the 1-20 GeV range. Ground-based telescopes whose energy ranges extend downward toward 10 GeV should make important measurements of the spectral cutoffs. The Gamma-ray Large Area Space Telescope (GLAST), now in planning for a launch in 2005, will provide a major advance in sensitivity, energy range, and sky coverage.

David J. Thompson

2001-01-03T23:59:59.000Z

113

Frontiers in Cosmic Rays  

E-Print Network (OSTI)

This rapporteur review covers selected results presented in the Parallel Session HEA2 (High Energy Astrophysics 2) of the 10th Marcel Grossmann Meeting on General Relativity, held in Rio de Janeiro, Brazil, July 2003. The subtopics are: ultra high energy cosmic ray anisotropies, the possible connection of these energetic particles with powerful gamma ray bursts, and new exciting scenarios with a strong neutrino-nucleon interaction in the atmosphere.

Luis A. Anchordoqui; Charles D. Dermer; Andreas Ringwald

2004-02-27T23:59:59.000Z

114

Gamma-Ray Bursts  

E-Print Network (OSTI)

Gamma-ray bursts are the most luminous explosions in the Universe, and their origin and mechanism are the focus of intense research and debate. More than three decades after their discovery, and after pioneering breakthroughs from space and ground experiments, their study is entering a new phase with the recently launched Swift satellite. The interplay between these observations and theoretical models of the prompt gamma ray burst and its afterglow is reviewed.

P. Meszaros

2006-05-09T23:59:59.000Z

115

ARPA-E and the Military Team Up on New Technologies and Summit Partnerships  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

and the Military Team Up on New Technologies and Summit and the Military Team Up on New Technologies and Summit Partnerships ARPA-E and the Military Team Up on New Technologies and Summit Partnerships January 31, 2013 - 1:06pm Addthis Secretary of the Navy Ray Mabus speaks to attendees at the 2011 Energy Innovation Summit in Washington, DC. | Energy Department photo. Secretary of the Navy Ray Mabus speaks to attendees at the 2011 Energy Innovation Summit in Washington, DC. | Energy Department photo. Alexa McClanahan Communications Support Contractor to ARPA-E What are the key facts? ARPA-E and the Navy are funding development of HVAC technology that could achieve 20-50% better fuel efficiency for soldiers in extreme conditions. Learn more about Defense Department and ARPA-E collaborations at the 2013 Energy Innovation Summit, held Feb. 25-27 outside Washington, DC.

116

Cosmic Rays and Gamma Ray Bursts From Microblazars  

E-Print Network (OSTI)

Highly relativistic jets from merger and accretion induced collapse of compact stellar objects, which may produce the cosmological gamma ray bursts (GRBs), are also very efficient and powerful cosmic ray accelerators. The expected luminosity, energy spectrum and chemical composition of cosmic rays from Galactic GRBs, most of which do not point in our direction, can explain the observed properties of Galactic cosmic rays.

Arnon Dar

1998-09-13T23:59:59.000Z

117

Gamma-ray events thunderclouds  

E-Print Network (OSTI)

Andromeda: A mission to determine the gamma-ray burst distance scale F.A. Harrison, W.R. Cook, T was submitted to the STEDI program, and will also be proposed as a NASA Small Explorer. Keywords: bursts, gamma-rays, small missions 1 SCIENTIFIC OBJECTIVES 1.1 Gamma-ray Bursts Gamma-ray bursts GRBs were discovered

California at Berkeley, University of

118

X-ray microtomography  

SciTech Connect

In this tutorial, we describe X-ray microtomography as a technique to nondestructively characterize material microstructure in three dimensions at a micron level spatial resolution. While commercially available laboratory scale instrumentation is available, we focus our attention on synchrotron-based systems, where we can exploit a high flux, monochromatic X-ray beam to produce high fidelity three-dimensional images. A brief description of the physics and the mathematical analysis behind the technique is followed by example applications to specific materials characterization problems, with a particular focus on the utilization of three-dimensional image processing that can be used to extract a wide range of useful information.

Landis, Eric N., E-mail: landis@maine.edu [Department of Civil and Environmental Engineering, University of Maine, 5711 Boardman Hall, Orono, Maine 04469 (United States); Keane, Denis T., E-mail: dtkeane@northwestern.edu [Department of Materials Science and Engineering, Northwestern University (United States); DND-CAT, Advanced Photon Source, Argonne National Laboratory, Bldg. 432/A002, 9700 S. Cass Ave, Argonne, Illinois 60439 (United States)

2010-12-15T23:59:59.000Z

119

RPU: a programmable ray processing unit for realtime ray tracing  

Science Conference Proceedings (OSTI)

Recursive ray tracing is a simple yet powerful and general approach for accurately computing global light transport and rendering high quality images. While recent algorithmic improvements and optimized parallel software implementations have increased ... Keywords: hardware architecture, programmable shading, ray processing unit, ray tracing

Sven Woop; Jrg Schmittler; Philipp Slusallek

2005-07-01T23:59:59.000Z

120

Fluctuation X-Ray Scattering  

SciTech Connect

The work supported by the grant was aimed at developing novel methods of finding the structures of biomolecules using x-rays from novel sources such as the x-ray free electron laser and modern synchrotrons

Saldin, PI: D. K.; Co-I's: J. C. H. Spence and P. Fromme

2013-01-25T23:59:59.000Z

Note: This page contains sample records for the topic "keynote ray mabus" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Ultrahigh Energy Cosmic Rays Detection  

Science Conference Proceedings (OSTI)

The paper describes methods used for the detection of cosmic rays with energies above 1018 eV (UHECR

Carla Aramo

2005-01-01T23:59:59.000Z

122

X-ray Security Screening  

Science Conference Proceedings (OSTI)

National and International Standards for X-ray Security Screening Applications. Summary: The primary objective of this ...

2013-03-13T23:59:59.000Z

123

Day 2 - Thurs Keynote - Chris Hart.ppt  

NLE Websites -- All DOE Office Websites (Extended Search)

Laboratory Laboratory August 28, 2008 Federal Aviation Administration 1 Improving Both Safety and Productivity At the Same Time Presentation to: Idaho National Laboratory Name: Christopher A. Hart Date: August 28, 2008 Federal Aviation Administration Idaho National Laboratory August 28, 2008 Federal Aviation Administration 2 Outline - The Context - Importance of Better Information - Importance of "System Think" - Safety Benefits - Productivity Benefits - Aviation Successes and Failures - The Role of Leadership Idaho National Laboratory August 28, 2008 Federal Aviation Administration 3 Information From Front Lines Improved Safety Process Plus Fuel Can Produce An Amazing Win-Win System Think Process AND Improved Productivity Idaho National Laboratory August 28, 2008 Federal Aviation Administration

124

Day 1 - Wed Keynote - Vince Trim.ppt  

NLE Websites -- All DOE Office Websites (Extended Search)

12 Document control number 0 5 10 15 20 25 30 35 40 0 1000 2000 3000 4000 5000 Hours On Wing At Low Temperature Removal Temperature Margin Degrees Celsius Actual R-Squared Value...

125

Day 1 - Wed Keynote - Vince Trim.ppt  

NLE Websites -- All DOE Office Websites (Extended Search)

Sustaining Relevance Through Change" Sustaining Relevance Through Change" Vince Trim President, Honeywell Federal Manufacturing & Technologies Integrated Safety Management Conference 27 August 2008 Honeywell Proprietary 2 Document control number "If you don't like change you're going to like irrelevance even less". General Eric Shinseki, Former Army Chief of Staff "Sustaining Relevance Through Change" Honeywell Proprietary 4 Document control number 0 5 10 15 20 25 30 35 40 Enplanements (Millions) 1983- 1987 1988- 1992 1993- 1997 1998- 2002 2003- 2007 5 Year Period * Enhanced Ground Proximity Warning System * Traffic Collision Avoidance System * Runaway Awareness System * Automated Landing System Source: NTSB publications US Airline Passenger Enplanements per Fatality (Millions) A change-focused mindset drove a 7X

126

Placeholder removed. Keynote Talk on Advanced Materials for ...  

Science Conference Proceedings (OSTI)

Symposium, Advanced Materials for Power Electronics, Power Conditioning, and Power Conversion ... Potential Ceramic Dielectrics for Air Force Applications.

127

Supporting sustainability with software - an industrial perspective (keynote)  

Science Conference Proceedings (OSTI)

Supporting sustainability with software is often summed up in the expression ??Green IT?? and directly relates to the reduction of CO2 emissions and energy used by IT. The amount of CO2 used in the IT industry covers 2\\% of the overall CO2 ...

Frank-Dieter Clesle

2012-06-01T23:59:59.000Z

128

TMS2013 Aluminum Keynote Session Examines Supply Chain ...  

Science Conference Proceedings (OSTI)

Nov 23, 2012 ... The global oil refining industry has undergone a dramatic upheaval over ... This was driven by crude oil changes at a refinery producing one of...

129

Contents 1. Executive Summary 2. Keynote Addresses 2.1 ...  

Science Conference Proceedings (OSTI)

... etc. (Distributed Reforming Production) ... forming. Any thermal treatments of the product or Mechanical forming (bending). ...

2007-11-28T23:59:59.000Z

130

Keynote Remarks to the MASDAR/World Future Energy Conference...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

sequestration projects have the potential to store more than one hundred years of CO2 emissions from all major sources of pollution in North America. Eventually, this will help...

131

Nanomaterials: Innovation (R&T&I) Roadmaps - 2020 Keynote Lecture  

Science Conference Proceedings (OSTI)

... with regard to the aeronautics and car industry and chemical and petroleum industries. ... Polysulfone /Multi-Walled Carbon Nanotube Hybrid Nanocomposites.

132

TMS2013 Keynote Session Looks at Impurities in the Aluminum ...  

Science Conference Proceedings (OSTI)

"Impacts of Impurities Introduced into the Aluminum Reduction Cell"; "Changes in Global Oil Refining and Its Impact on Anode Quality Petroleum Coke"

133

Commercialization of NanoMaterials 2006: Keynote: The National ...  

Science Conference Proceedings (OSTI)

Sep 19, 2006 ... customers in technology, energy, healthcare and industrial markets ... The interactive and integrated nature of nanotechnology is leading to the creation of new value ... As American jobs move offshore, the interest mounts.

134

Dr. Patrick Gallagher, Opening Keynote, Grid-Interop 2009  

Science Conference Proceedings (OSTI)

... The creation of a Smart Grid is a critical national ... Accomplishing this objective was the job assigned to NIST in the Energy Independence and ...

2010-10-05T23:59:59.000Z

135

Day 2 - Thurs Keynote - Chris Hart.ppt  

NLE Websites -- All DOE Office Websites (Extended Search)

labor-management relations Labor reluctant to tell management what's wrong Retraininglearning curve of new employee if "perpetrator" moved or fired Adverse impacts of...

136

Administrator Adam Sieminskis keynote remarks at the Bipartisan ...  

U.S. Energy Information Administration (EIA)

the Department of Energy, ... In conclusion, I want to stress that one of the central goals in DOEs strategic Plan is to lead the national conversation on energy.

137

Keynote Remarks at Technical Aspects of Botnets Workshop  

Science Conference Proceedings (OSTI)

... that followed, we have learned that many of the leading companiescompanies like Comcast and CenturyLink and Googlehave already begun ...

2013-07-08T23:59:59.000Z

138

The Quality of Web Data Keynote @ ICIQ 2012  

E-Print Network (OSTI)

Meaghan C. Gragg e. John & yali C. Gregory LindaS.Griffin&RobertD.Keliher,Sr. Dustin G. Hall Whitney C remedies · Fassett, Anthony & Taylor, P.A. secured transactions · Avila Rodriguez Hernandez Mena & Ferri. Lawrence & elizabeth e. Heinkel Brett T. & Rhonda K. Hendee* eugenio Hernandez Hicks, Porter, ebenfeld

Weske, Mathias

139

Fusion energy development: Breakeven and beyond: Keynote address  

SciTech Connect

The scientific feasibility, technological inevitability, and economic necessity of fusion as an energy source are discussed.

Furth, H.P.

1988-02-01T23:59:59.000Z

140

Assistant Secretary Patricia Hoffman to Deliver Keynote Address...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Haught (SGIG activities in the mid-Atlantic region and Vermont), Akhlesh Kaushiva (SGIG Distribution Automation projects), Don Macdonald (SGIG AMI Projects and Customer...

Note: This page contains sample records for the topic "keynote ray mabus" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

X-ray afterglows from gamma-ray bursts  

E-Print Network (OSTI)

We consider possible interpretations of the recently detected X- ray afterglow from the gamma-ray burst source GRB 970228. Cosmological and Galactic models of gamma-ray bursts predict different flux and spectral evolution of X-ray afterglows. We show that models based on adiabatic expansion of relativistic forward shocks require very efficient particle energization or post-burst re-acceleration during the expansion. Cooling neutron star models predict a very distinctive spectral and flux evolution that can be tested in current X-ray data.

M. Tavani

1997-03-24T23:59:59.000Z

142

Tunable X-ray source  

DOE Patents (OSTI)

A method for the production of X-ray bunches tunable in both time and energy level by generating multiple photon, X-ray, beams through the use of Thomson scattering. The method of the present invention simultaneously produces two X-ray pulses that are tunable in energy and/or time.

Boyce, James R. (Williamsburg, VA)

2011-02-08T23:59:59.000Z

143

Cost prediction for ray shooting  

Science Conference Proceedings (OSTI)

The ray shooting problem arises in many different contexts. For example, solving it efficiently would remove a bottleneck when images are ray-traced in computer graphics. Unfortunately, theoretical solutions to the problem are not very practical, ... Keywords: average performance, cost model, cost prediction, octree, ray shooting, space decomposition

Boris Aronov; Herv Brnnimann; Allen Y. Chang; Yi-Jen Chiang

2002-06-01T23:59:59.000Z

144

Cosmic Ray Telescopes  

NLE Websites -- All DOE Office Websites (Extended Search)

Cosmic Ray Muon Detectors Cosmic Ray Muon Detectors Particle Physics Using Nature's Accelerator Somewhere out there is a list of "10 Things a Physics Teacher is Least Likely to Say." If one were to find this list, it would have on it such gems as #7. Let's challenge the PE Dept to a game of rugby and #4. I don't care if you understand the concept, just give me the correct answer to 12 sig figs. Finally, you'd get down to the biggie, the thing physics teachers never say: #1. Let's do a particle physics lab right here at Podunk Corners High! The traditional reasons for this are that everyone knows that particle physics is only done with Vastly Expensive and Complicated Equipment run by casts of thousands of Highly Qualified Scientists and that particle physics is Difficult and Arcane.

145

Scanning x-ray microscope  

Science Conference Proceedings (OSTI)

A scanning x-ray microscope is described including: an x-ray source capable of emitting a beam of x-rays; a collimator positioned to receive the beam of x-rays and to collimate this beam, a focusing cone means to focus the beam of x-rays, directed by the collimator, onto a focal plane, a specimen mount for supporting a specimen in the focal plane to receive the focused beam of x-rays, and x-ray beam scanning means to relatively move the specimen and the focusing cone means and collimator to scan the focused x-ray beam across the specimen. A detector is disposed adjacent the specimen to detect flourescent photons emitted by the specimen upon exposure to the focused beam of x-rays to provide an electrical output representative of this detection. Means are included for displaying and/or recording the information provided by the output from the detector, as are means for providing information to the recording and/or display means representative of the scan rate and position of the focused x-ray beam relative to the specimen whereby the recording and/or display means can correlate the information received to record and/or display quantitive and distributive information as to the quantity and distribution of elements detected in the specimen. Preferably there is provided an x-ray beam modulation means upstream, relative to the direction of emission of the xray beam, of the focusing cone means.

Wang, C.

1982-02-23T23:59:59.000Z

146

X-ray lithography source  

SciTech Connect

A high-intensity, inexpensive X-ray source for X-ray lithography for the production of integrated circuits. Foil stacks are bombarded with a high-energy electron beam of 25 to 250 MeV to produce a flux of soft X-rays of 500 eV to 3 keV. Methods of increasing the total X-ray power and making the cross section of the X-ray beam uniform are described. Methods of obtaining the desired X-ray-beam field size, optimum frequency spectrum and elminating the neutron flux are all described. A method of obtaining a plurality of station operation is also described which makes the process more efficient and economical. The satisfying of these issues makes transition radiation an exellent moderate-priced X-ray source for lithography.

Piestrup, Melvin A. (Woodside, CA); Boyers, David G. (Mountain View, CA); Pincus, Cary (Sunnyvale, CA)

1991-01-01T23:59:59.000Z

147

X-ray lithography source  

DOE Patents (OSTI)

A high-intensity, inexpensive X-ray source for X-ray lithography for the production of integrated circuits is disclosed. Foil stacks are bombarded with a high-energy electron beam of 25 to 250 MeV to produce a flux of soft X-rays of 500 eV to 3 keV. Methods of increasing the total X-ray power and making the cross section of the X-ray beam uniform are described. Methods of obtaining the desired X-ray-beam field size, optimum frequency spectrum and eliminating the neutron flux are all described. A method of obtaining a plurality of station operation is also described which makes the process more efficient and economical. The satisfying of these issues makes transition radiation an excellent moderate-priced X-ray source for lithography. 26 figures.

Piestrup, M.A.; Boyers, D.G.; Pincus, C.

1991-12-31T23:59:59.000Z

148

LIGHT CURVES OF SWIFT GAMMA RAY BURSTS  

E-Print Network (OSTI)

Recent observations from the Swift gamma-ray burst mission indicate that a fraction of gamma ray bursts are characterized by a canonical behaviour of the X-ray afterglows. We present an effective theory which allows us to account for X-ray light curves of both (short- long) gamma ray bursts and X-ray rich flashes. We propose that gamma ray bursts originate from massive magnetic powered pulsars. Subject headings: gamma-rays: bursts 1.

Paolo Cea

2006-01-01T23:59:59.000Z

149

Sunil Sinha  

Science Conference Proceedings (OSTI)

Aug 5, 2013 ... The X-ray microdiffraction experiment was done at 34ID beam line in Advanced Photon Source (APS). 3:35 PM Keynote High Energy X-ray...

150

Gamma Ray Bursts Sudden, intense flashes of gamma rays  

E-Print Network (OSTI)

. Sakamoto1,12 , C. L. Sarazin13 , P. Schady6,10 , M. Stamatikos1,12 & S. E. Woosley14 Gamma-ray bursts (GRBs. Identification of two classes of gamma-ray bursts. Astrophys. J. 413, L101­L104 (1993). 2. Fruchter, A. et al). 3. Woosley, S. E. Gamma-ray bursts from stellar mass accretion disks around black holes. Astrophys

Washington at Seattle, University of - Department of Physics, Electroweak Interaction Research Group

151

dosimetry of x-rays, gamma rays and electrons  

Science Conference Proceedings (OSTI)

... NIST and BIPM Standards for Air Kerma in Medium-Energy X-rays ... of the codes are available from the Government Printing Office, Washington, DC ...

2013-06-28T23:59:59.000Z

152

X-ray Flares in Gamma-Ray Bursts.  

E-Print Network (OSTI)

??Data from the Swift mission have now shown that flares are a common component of Gamma-Ray Burst afterglows, appearing in roughly 50% of GRBs to (more)

Morris, David

2008-01-01T23:59:59.000Z

153

Miniature x-ray source  

DOE Patents (OSTI)

A miniature x-ray source capable of producing broad spectrum x-ray emission over a wide range of x-ray energies. The miniature x-ray source comprises a compact vacuum tube assembly containing a cathode, an anode, a high voltage feedthru for delivering high voltage to the anode, a getter for maintaining high vacuum, a connection for an initial vacuum pump down and crimp-off, and a high voltage connection for attaching a compact high voltage cable to the high voltage feedthru. At least a portion of the vacuum tube wall is highly x-ray transparent and made, for example, from boron nitride. The compact size and potential for remote operation allows the x-ray source, for example, to be placed adjacent to a material sample undergoing analysis or in proximity to the region to be treated for medical applications.

Trebes, James E. (Livermore, CA); Stone, Gary F. (Livermore, CA); Bell, Perry M. (Tracy, CA); Robinson, Ronald B. (Modesto, CA); Chornenky, Victor I. (Minnetonka, MN)

2002-01-01T23:59:59.000Z

154

Gamma-ray burst populations.  

E-Print Network (OSTI)

??Over the last fifty years the field of gamma-ray bursts has shown incredible growth, but the amassing of data has also left observers and theorists (more)

Virgili, Francisco J.

2011-01-01T23:59:59.000Z

155

Synchrotron X-ray Measurements  

Science Conference Proceedings (OSTI)

... fine structure (EXAFS) spectroscopy; (3) variable kinetic energy X-ray ... advanced materials is critical to the development and optimization of products ...

2012-10-04T23:59:59.000Z

156

X-ray Absorption Spectroscopy  

SciTech Connect

This review gives a brief description of the theory and application of X-ray absorption spectroscopy, both X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS), especially, pertaining to photosynthesis. The advantages and limitations of the methods are discussed. Recent advances in extended EXAFS and polarized EXAFS using oriented membranes and single crystals are explained. Developments in theory in understanding the XANES spectra are described. The application of X-ray absorption spectroscopy to the study of the Mn4Ca cluster in Photosystem II is presented.

Yano, Junko; Yachandra, Vittal K.

2009-07-09T23:59:59.000Z

157

Light Curves of Swift Gamma Ray Bursts  

E-Print Network (OSTI)

Recent observations from the Swift gamma-ray burst mission indicate that a fraction of gamma ray bursts are characterized by a canonical behaviour of the X-ray afterglows. We present an effective theory which allows us to account for X-ray light curves of both (short - long) gamma ray bursts and X-ray rich flashes. We propose that gamma ray bursts originate from massive magnetic powered pulsars.

Paolo Cea

2006-06-05T23:59:59.000Z

158

Ultrahigh Energy Cosmic Rays and Prompt TeV Gamma Rays from Gamma Ray Bursts  

E-Print Network (OSTI)

Gamma Ray Bursts (GRBs) have been proposed as one {\\it possible} class of sources of the Ultrahigh Energy Cosmic Ray (UHECR) events observed up to energies $\\gsim10^{20}\\ev$. The synchrotron radiation of the highest energy protons accelerated within the GRB source should produce gamma rays up to TeV energies. Here we briefly discuss the implications on the energetics of the GRB from the point of view of the detectability of the prompt TeV gamma rays of proton-synchrotron origin in GRBs in the up-coming ICECUBE muon detector in the south pole.

Pijushpani Bhattacharjee; Nayantara Gupta

2003-05-12T23:59:59.000Z

159

A hypercube Ray-tracer  

Science Conference Proceedings (OSTI)

We describe a hypercube ray-tracing program for rendering computer graphics. For small models, which fit in the memory of a single processor, the ray-tracer uses a scattered decomposition of pixels to balance the load, and achieves a very high efficiency. ...

J. Salmon; J. Goldsmith

1989-01-01T23:59:59.000Z

160

Gamma Ray Pulsars: Multiwavelength Observations  

E-Print Network (OSTI)

High-energy gamma rays are a valuable tool for studying particle acceleration and radiation in the magnetospheres of energetic pulsars. The seven or more pulsars seen by instruments on the Compton Gamma Ray Observatory (CGRO) show that: the light curves usually have double-peak structures (suggesting a broad cone of emission); gamma rays are frequently the dominant component of the radiated power; and all the spectra show evidence of a high-energy turnover. For all the known gamma-ray pulsars, multiwavelength observations and theoretical models based on such observations offer the prospect of gaining a broad understanding of these rotating neutron stars. The Gamma-ray Large Area Space Telescope (GLAST), now in planning for a launch in 2007, will provide a major advance in sensitivity, energy range, and sky coverage.

David J. Thompson

2003-12-10T23:59:59.000Z

Note: This page contains sample records for the topic "keynote ray mabus" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Current Topics in Gamma-Ray Astrophysics  

Science Conference Proceedings (OSTI)

... into e+e pairs ends up as rays. Figure 1 shows a calculation of -ray burst luminosity as ... The integrated energy in gamma-rays from the calculated ...

2000-03-14T23:59:59.000Z

162

Studying Gamma Ray Bursts from a  

E-Print Network (OSTI)

Studying Gamma Ray Bursts from a new perspective! {... Unraveling some mysteries and adding new Radio Op0cal X-ray Short ( energy -ray photons... ... accompained by a considerable long las0ng emission

?umer, Slobodan

163

Lecture 7Lecture 7 The GammaThe Gamma--RayRay  

E-Print Network (OSTI)

Milagro­A TeV Observatory for Gamma Ray Bursts B.L. Dingus and the Milagro Collaboration Los energy gamma-rays from gamma-ray bursts. The highest energy gamma rays supply very strong constraints on the nature of gamma-ray burst sources as well as fundamental physics. Because the highest energy gamma-rays

164

X-Ray Data Booklet X-RAY DATA BOOKLET  

E-Print Network (OSTI)

.10.Re 1. Introduction Mendelevium (Z=101) and Lawrencium (Z=103) isotopes have been dis- covered nearly isotopes have been studied so far using prompt gamma- ray spectroscopy: the neutron-odd 253No [9

Meagher, Mary

165

Fiber fed x-ray/gamma ray imaging apparatus  

SciTech Connect

X-ray/gamma ray imaging apparatus is disclosed for detecting the position, energy, and intensity of x-ray/gamma ray radiation comprising scintillation means disposed in the path of such radiation and capable of generating photons in response to such radiation; first photodetection means optically bonded to the scintillation means and capable of generating an electrical signal indicative of the intensity, and energy of the radiation detected by the scintillation means; second photodetection means capable of generating an electrical signal indicative of the position of the radiation in the radiation pattern; and means for optically coupling the scintillation means to the second photodetection means. The photodetection means are electrically connected to control and storage means which may also be used to screen out noise by rejecting a signal from one photodetection means not synchronized to a signal from the other photodetection means; and also to screen out signals from scattered radiation.

Hailey, Charles J. (San Francisco, CA); Ziock, Klaus-Peter (Livermore, CA)

1992-01-01T23:59:59.000Z

166

Detectors of Cosmic Rays, Gamma Rays, and Neutrinos  

SciTech Connect

We summarize the main features, properties and performances of the typical detectors in use in Cosmic Ray Physics. A brief historical and general introduction will focus on the main classes and requirements of such detectors.

Altamirano, A. [Departamento de Fisica, Informatica y Matematicas, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia (Peru); Centro de Tecnologias de Informacion y Comunicaciones (CTIC), Universidad Nacional de Ingenieria, Lima (Peru); Navarra, G. [Dipartimento di Fisica Generale dell'Universita' and INFN, Torino (Italy)

2009-04-30T23:59:59.000Z

167

X-ray Spectral Properties of Gamma-Ray Bursts  

E-Print Network (OSTI)

We summarize the spectral characteristics of a sample of 22 bright gamma-ray bursts detected with the gamma-ray burst sensors aboard the satellite Ginga. This instrument employed a proportional and scintillation counter to provide sensitivity to photons in the 2 - 400 keV range, providing a unique opportunity to characterize the largely unexplored X-ray properties of gamma-ray bursts. The photon spectra of the Ginga bursts are well described by a low energy slope, a bend energy, and a high energy slope. In the energy range where they can be compared, this result is consistent with burst spectral analyses obtained from the BATSE experiment aboard the Compton Observatory. However, below 20 keV we find evidence for a positive spectral number index in approximately 40% of our burst sample, with some evidence for a strong rolloff at lower energies in a few events. There is a correlation (Pearson's r = -0.62) between the low energy slope and the bend energy. We find that the distribution of spectral bend energies extends below 10 keV. The observed ratio of energy emitted in the X-rays relative to the gamma-rays can be much larger than a few percent and, in fact, is sometimes larger than unity. The average for our sample is 24%.

T. E. Strohmayer; E. E. Fenimore; T. Murakami; A. Yoshida

1997-12-18T23:59:59.000Z

168

X-ray Transition Energies Search Form  

Science Conference Proceedings (OSTI)

[skip navigation] X-ray Transition Energies Database Main Page Search for X-ray transition energies by element(s), transition ...

169

NREL: Energy Sciences - B. Ray Stults  

NLE Websites -- All DOE Office Websites (Extended Search)

Chemical & Materials Science Computational Science News Events Printable Version B. Ray Stults Ph.D. - Associate Laboratory Director, Energy Sciences Ray Stults is the Associate...

170

X-ray flashes and X-ray rich gamma ray bursts. Memorie della Societa Astronomica Italiana  

E-Print Network (OSTI)

Abstract. X-ray flashes are detected in the Wide Field Cameras on BeppoSAX in the energy range 2-25 keV as bright X-ray sources lasting of the order of minutes, but remaining undetected in the Gamma Ray Bursts Monitor on BeppoSAX. They have properties very similar to the x-ray counterparts of GRBs and account for some of the Fast X-ray Transient events seen in almost every x-ray satellite. We review their X-ray properties and show that x-ray flashes are in fact very soft, x-ray rich, untriggered gamma ray bursts, in which the peak energy in 2-10 keV x-rays could be up to a factor of 100 larger than the peak energy in the 50-300 keV gamma ray range. The frequency is ? 100 yr ?1. 1 Fast X-ray Transients/High-latitude X-ray Transients Fast X-ray Transients have been observed with many x-ray satellites. In particular they are seen with x-ray instruments that scan the entire sky on a regular basis. Such events are detected in one sky scan and disappeared in the next, typically limiting the duration to be longer than a minute and shorter than a few hours. For this reason they are called Fast Transients. The first transients

John Heise; Jean In t Z; Peter M. Woods

2001-01-01T23:59:59.000Z

171

Gamma-Ray Burst Lines  

E-Print Network (OSTI)

The evidence for spectral features in gamma-ray bursts is summarized. As a guide for evaluating the evidence, the properties of gamma-ray detectors and the methods of analyzing gamma-ray spectra are reviewed. In the 1980's, observations indicated that absorption features below 100 keV were present in a large fraction of bright gamma-ray bursts. There were also reports of emission features around 400 keV. During the 1990's the situation has become much less clear. A small fraction of bursts observed with BATSE have statistically significant low-energy features, but the reality of the features is suspect because in several cases the data of the BATSE detectors appear to be inconsistent. Furthermore, most of the possible features appear in emission rather than the expected absorption. Analysis of data from other instruments has either not been finalized or has not detected lines.

Michael S. Briggs

1999-10-20T23:59:59.000Z

172

X-ray Imaging Workshop  

NLE Websites -- All DOE Office Websites (Extended Search)

Imaging and Spectro-microscopy: Imaging and Spectro-microscopy: the Present and the Future Stanford Synchrotron Radiation Laboratory October 8-9, 2002 Organizers: John Miao & Keith Hodgson A workshop on "X-ray Imaging and Spectro-microscopy: the Present and the Future" was held on October 8-9, 2002. This workshop, organized by John Miao (SSRL) and Keith Hodgson (SSRL) provided a forum to discuss the scientific applications of a variety of imaging and spectro-microscopic techniques, including photoemission electron microscopy (PEEM), angle resolved photoemission spectroscopy (ARPES), coherent diffraction imaging, x-ray microscopy, micro-tomography, holographic imaging, and x-ray micro-probe. Twelve invited speakers discussed the important scientific applications of these techniques, and also predicted the future scientific directions with the advance of instrumentation and x-ray sources. The workshop was well attended with over fifty registered attendees.

173

Modeling gamma-ray bursts.  

E-Print Network (OSTI)

??Discovered serendipitously in the late 1960s, gamma-ray bursts (GRBs) are huge explosions of energy that happen at cosmological distances. They provide a grand physical playground (more)

Maxham, Amanda

2011-01-01T23:59:59.000Z

174

Miniature x-ray source  

DOE Patents (OSTI)

A miniature x-ray source utilizing a hot filament cathode. The source has a millimeter scale size and is capable of producing broad spectrum x-ray emission over a wide range of x-ray energies. The miniature source consists of a compact vacuum tube assembly containing the hot filament cathode, an anode, a high voltage feedthru for delivering high voltage to the cathode, a getter for maintaining high vacuum, a connector for initial vacuum pump down and crimp-off, and a high voltage connection for attaching a compact high voltage cable to the high voltage feedthru. At least a portion of the vacuum tube wall is fabricated from highly x-ray transparent materials, such as sapphire, diamond, or boron nitride.

Trebes, James E. (Livermore, CA); Bell, Perry M. (Tracy, CA); Robinson, Ronald B. (Modesto, CA)

2000-01-01T23:59:59.000Z

175

Gamma Ray Bursts and CETI  

E-Print Network (OSTI)

Gamma ray burst sources are isotropically distributed. They could be located at distances $\\sim 1000$ AU. (Katz \\cite{JK92}) GRB signals have many narrow peaks that are unresolved at the millisecond time resolution of existing observations. \\cite{JK87} CETI could use stars as gravitational lenses for interstellar gamma ray laser beam communication. Much better time resolution of GRB signals could rule out (or confirm?) the speculative hypothesis that GRB = CETI.

Frank D. Smith Jr

1993-02-10T23:59:59.000Z

176

Tokamak x ray diagnostic instrumentation  

SciTech Connect

Three classes of x-ray diagnostic instruments enable measurement of a variety of tokamak physics parameters from different features of the x-ray emission spectrum. (1) The soft x-ray (1 to 50 keV) pulse-height-analysis (PHA) diagnostic measures impurity concentrations from characteristic line intensities and the continuum enhancement, and measures the electron temperature from the continuum slope. (2) The Bragg x-ray crystal spectrometer (XCS) measures the ion temperature and neutral-beam-induced toroidal rotation velocity from the Doppler broadening and wavelength shift, respectively, of spectral lines of medium-Z impurity ions. Impurity charge state distributions, precise wavelengths, and inner-shell excitation and recombination rates can also be studied. X rays are diffracted and focused by a bent crystal onto a position-sensitive detector. The spectral resolving power E/..delta..E is greater than 10/sup 4/ and time resolution is 10 ms. (3) The x-ray imaging system (XIS) measures the spatial structure of rapid fluctuations (0.1 to 100 kHZ) providing information on MHD phenomena, impurity transport rates, toroidal rotation velocity, plasma position, and the electron temperature profile. It uses an array of silicon surface-barrier diodes which view different chords of the plasma through a common slot aperture and operate in current (as opposed to counting) mode. The effectiveness of shields to protect detectors from fusion-neutron radiation effects has been studied both theoretically and experimentally.

Hill, K.W.; Beiersdorfer, P.; Bitter, M.; Fredrickson, E.; Von Goeler, S.; Hsuan, H.; Johnson, L.C.; Liew, S.L.; McGuire, K.; Pare, V.

1987-01-01T23:59:59.000Z

177

Neutrinos from Gamma Ray Bursts  

E-Print Network (OSTI)

The observed fluxes of cosmic rays and gamma rays are used to infer the maximum allowed high-energy neutrino flux allowed for Gamma Ray Bursts (GRBs), following Mannheim, Protheroe, and Rachen (2000). It is shown that if GRBs produce the ultrahigh-energy cosmic rays, they should contribute (a) at least 10% of the extragalactic gamma ray background between 3 MeV and 30 GeV, contrary to their observed energy flux which is only a minute fraction of this flux, and (b) a cumulative neutrino flux a factor of 20 below the AMANDA (Neutrino 2000) limit on isotropic neutrinos. This could have two implications, either GRBs do not produce the ultrahigh energy cosmic rays or that the GRBs are strongly beamed and emit most of their power at energies well above 100 GeV implausibly increasing the energy requirements, but consistent with the marginal detections of a few low-redshift GRBs by MILAGRITO, HEGRA-AIROBICC, and the Tibet-Array. All crucial measurements to test the models will be available in the next few years. These are measurements of (i) high-energy neutrinos with AMANDA-ICECUBE or an enlarged ANTARES/NESTOR ocean detector, (ii) GRB redshifts from HETE-2 follow-up studies, and (iii) GRB spectra above 10 GeV with low-threshold imaging air Cherenkov telescopes such as MAGIC and the space telescopes AGILE and GLAST.

Karl Mannheim

2000-10-18T23:59:59.000Z

178

Gamma-Ray Bursts, Ultra High Energy Cosmic Rays, and Cosmic Gamma-Ray Background  

E-Print Network (OSTI)

We argue that gamma-ray bursts (GRBs) may be the origin of the cosmic gamma-ray background radiation observed in GeV range. It has theoretically been discussed that protons may carry a much larger amount of energy than electrons in GRBs, and this large energy can be radiated in TeV range by synchrotron radiation of ultra-high-energy protons (\\sim 10^{20} eV). The possible detection of GRBs above 10 TeV suggested by the Tibet and HEGRA groups also supports this idea. If this is the case, most of TeV gamma-rays from GRBs are absorbed in intergalactic fields and eventually form GeV gamma-ray background, whose flux is in good agreement with the recent observation.

Tomonori Totani

1998-10-14T23:59:59.000Z

179

Gamma ray bursts ROBERT S MACKAY  

E-Print Network (OSTI)

Gamma ray bursts ROBERT S MACKAY COLIN ROURKE We propose that a gamma ray burst is a kinematic Gamma ray bursts are intense flashes of electromagnetic radiation of cosmic origin lasting from ten accepted mechanism. We propose that a gamma ray burst is simply a kinematic effect, namely the effect

Rourke, Colin

180

Gamma-RayGamma-Ray Bursts: from SwiftBursts: from Swift  

E-Print Network (OSTI)

Gamma-RayGamma-Ray Bursts: from SwiftBursts: from Swift to GLASTto GLAST Bing ZhangBing ZhangGehrels, et al), et al) #12;Gamma-ray bursts: the mostGamma-ray bursts: the most violent explosions Bursts Apparently high gamma-ray efficiency. Highly magnetized flow? Roming et al., 2005 #12;Surprises

California at Santa Cruz, University of

Note: This page contains sample records for the topic "keynote ray mabus" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Compact x-ray source and panel  

SciTech Connect

A compact, self-contained x-ray source, and a compact x-ray source panel having a plurality of such x-ray sources arranged in a preferably broad-area pixelized array. Each x-ray source includes an electron source for producing an electron beam, an x-ray conversion target, and a multilayer insulator separating the electron source and the x-ray conversion target from each other. The multi-layer insulator preferably has a cylindrical configuration with a plurality of alternating insulator and conductor layers surrounding an acceleration channel leading from the electron source to the x-ray conversion target. A power source is connected to each x-ray source of the array to produce an accelerating gradient between the electron source and x-ray conversion target in any one or more of the x-ray sources independent of other x-ray sources in the array, so as to accelerate an electron beam towards the x-ray conversion target. The multilayer insulator enables relatively short separation distances between the electron source and the x-ray conversion target so that a thin panel is possible for compactness. This is due to the ability of the plurality of alternating insulator and conductor layers of the multilayer insulators to resist surface flashover when sufficiently high acceleration energies necessary for x-ray generation are supplied by the power source to the x-ray sources.

Sampayon, Stephen E. (Manteca, CA)

2008-02-12T23:59:59.000Z

182

Neutrinos from Gamma Ray Bursts  

E-Print Network (OSTI)

We show that the detection of neutrinos from a typical gamma ray burst requires a kilometer-scale detector. We argue that large bursts should be visible with the neutrino telescopes under construction. We emphasize the 3 techniques by which neutrino telescopes can perform this search: by triggering on i) bursts of muons from muon neutrinos, ii) muons from air cascades initiated by high energy gamma rays and iii) showers made by relatively low energy ($\\simeq 100\\,\\mev$) electron neutrinos. Timing of neutrino-photon coincidences may yield a measurement of the neutrino mass to order $10^{-5}$~eV, an interesting range in light of the solar neutrino anomaly.

F. Halzen; G. Jaczko

1996-02-07T23:59:59.000Z

183

Cosmic-ray sum rules  

SciTech Connect

We introduce new sum rules allowing to determine universal properties of the unknown component of the cosmic rays; we show how they can be used to predict the positron fraction at energies not yet explored by current experiments, and to constrain specific models.

Frandsen, Mads T. [Rudolf Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP (United Kingdom); Masina, Isabella [Dip. di Fisica dell'Universita di Ferrara and INFN Sez. di Ferrara, Via Saragat 1, I-44100 Ferrara (Italy); CP3-Origins, University of Southern Denmark, Campusvej 55, DK-5230 Odense M (Denmark); Sannino, Francesco [CP3-Origins, University of Southern Denmark, Campusvej 55, DK-5230 Odense M (Denmark)

2011-06-15T23:59:59.000Z

184

Chest x-Rays | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Chest x-Rays Chest x-Rays Chest x-Rays Chest X-ray B-Reading The B-reading is a special reading of a standard chest x-ray film performed by a physician certified by the National Institute for Occupational Safety and Health (NIOSH). The reading looks for changes on the chest x-ray that may indicate exposure and disease caused by agents such as asbestos or silica. The B-reading is considered a special reading because doctors who are certified by NIOSH to perform B-readings use a specific protocol to read and record the findings as developed by the International Labour Organization (ILO). The ILO's protocol provides rules for systematically examining the x-ray in a step-by-step method and recording certain abnormalities or changes on the chest x-ray that can be attributable to

185

Gamma ray astrophysics: the EGRET results  

E-Print Network (OSTI)

Cosmic gamma rays provide insight into some of the most dynamic processes in the Universe. At the dawn of a new generation of gamma-ray telescopes, this review summarizes results from the Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory, the principal predecessor mission studying high-energy photons in the 100 MeV energy range. EGRET viewed a gamma-ray sky dominated by prominent emission from the Milky Way, but featuring an array of other sources, including quasars, pulsars, gamma-ray bursts, and many sources that remain unidentified. A central feature of the EGRET results was the high degree of variability seen in many gamma-ray sources, indicative of the powerful forces at work in objects visible to gamma-ray telescopes.

D J Thompson

2008-11-05T23:59:59.000Z

186

Spectral analysis of X-ray binaries  

E-Print Network (OSTI)

In this thesis, I present work from three separate research projects associated with observations of X-ray binaries. Two of those revolve around spectral characteristics of neutron star low-mass X-ray binaries (NS-LMXBs), ...

Fridriksson, Joel Karl

2011-01-01T23:59:59.000Z

187

Stellar Sources of Gamma-ray Bursts  

E-Print Network (OSTI)

Correlation analysis of Swift gamma-ray burst coordinates and nearby star locations (catalog Gliese) reveals 4 coincidences with good angular accuracy. The random probability is 4\\times 10^{-5}, so evidencing that coincident stars are indeed gamma-ray burst sources. Some additional search of stellar gamma-ray bursts is discussed.

Luchkov, B I

2011-01-01T23:59:59.000Z

188

Fermi Observations of Gamma?ray Bursts  

Science Conference Proceedings (OSTI)

The gamma?ray emission mechanism of Gamma?ray bursts (GRBs) are still unknown. Fermi Gamma?ray Space Telescope successfully detected high?energy (> 100 MeV) emission from 17 GRBs since its launch. Fermi revealed the distinct temporal behaviors and extra spectral component from high?energy emission. These new observational results are driving many theoretical implications

Masanori Ohno; The Fermi?LAT collaborations; The GBM collaborations

2010-01-01T23:59:59.000Z

189

Cryotomography x-ray microscopy state  

Science Conference Proceedings (OSTI)

An x-ray microscope stage enables alignment of a sample about a rotation axis to enable three dimensional tomographic imaging of the sample using an x-ray microscope. A heat exchanger assembly provides cooled gas to a sample during x-ray microscopic imaging.

Le Gros, Mark (Berkeley, CA); Larabell, Carolyn A. (Berkeley, CA)

2010-10-26T23:59:59.000Z

190

Multifrequency Observations of Gamma-Ray Burst  

E-Print Network (OSTI)

Neither a flaring nor a quiescent counterpart to a gamma-ray burst has yet been convincingly identified at any wavelength region. The present status of the search for counterparts of classical gamma-ray bursts is given. Particular emphasis is put on the search for flaring counterparts, i.e. emission during or shortly after the gamma-ray emission.

J. Greiner

1995-10-04T23:59:59.000Z

191

Microgap x-ray detector  

DOE Patents (OSTI)

An x-ray detector which provides for the conversion of x-ray photons into photoelectrons and subsequent amplification of these photoelectrons through the generation of electron avalanches in a thin gas-filled region subject to a high electric potential. The detector comprises a cathode (photocathode) and an anode separated by the thin, gas-filled region. The cathode may comprise a substrate, such a beryllium, coated with a layer of high atomic number material, such as gold, while the anode can be a single conducting plane of material, such as gold, or a plane of resistive material, such as chromium/silicon monoxide, or multiple areas of conductive or resistive material, mounted on a substrate composed of glass, plastic or ceramic. The charge collected from each electron avalanche by the anode is passed through processing electronics to a point of use, such as an oscilloscope.

Wuest, Craig R. (Danville, CA); Bionta, Richard M. (Livermore, CA); Ables, Elden (Livermore, CA)

1994-01-01T23:59:59.000Z

192

X-ray transmissive debris shield  

DOE Patents (OSTI)

An X-ray debris shield for use in X-ray lithography that is comprised of an X-ray window having a layer of low density foam exhibits increased longevity without a substantial increase in exposure time. The low density foam layer serves to absorb the debris emitted from the X-ray source and attenuate the shock to the window so as to reduce the chance of breakage. Because the foam is low density, the X-rays are hardly attenuated by the foam and thus the exposure time is not substantially increased.

Spielman, R.B.

1996-05-21T23:59:59.000Z

193

X-ray transmissive debris shield  

DOE Patents (OSTI)

An X-ray debris shield for use in X-ray lithography that is comprised of an X-ray window having a layer of low density foam exhibits increased longevity without a substantial increase in exposure time. The low density foam layer serves to absorb the debris emitted from the X-ray source and attenuate the shock to the window so as to reduce the chance of breakage. Because the foam is low density, the X-rays are hardly attenuated by the foam and thus the exposure time is not substantially increased.

Spielman, Rick B. (Albuquerque, NM)

1996-01-01T23:59:59.000Z

194

The Diverse Environments of Gamma-Ray Bursts  

E-Print Network (OSTI)

of a Very Bright Gamma- Ray Burst in a Galactic Halo 3.1Galaxies of Dark Gamma-Ray Bursts: Observational Constraints1.3 Gamma-Ray Burst Classi?cation . . . . . . 1.4 Gamma-Ray

Perley, Daniel Alan

2011-01-01T23:59:59.000Z

195

The Ulysses Catalog of Solar Hard X-Ray Flares  

E-Print Network (OSTI)

its Solar X-ray/Cosmic Gamma-Ray Burst Experiment (GRB) hasInstrument The Ulysses Gamma-Ray Burst (GRB) instrument, hasrate due to a cosmic gamma-ray burst or a solar ?are, but we

Tranquille, C.; Hurley, K.; Hudson, H. S.

2009-01-01T23:59:59.000Z

196

APS Bending Magnet X-rays and  

NLE Websites -- All DOE Office Websites (Extended Search)

Irradiation of Nd-Fe-B Permanent Magnets with Irradiation of Nd-Fe-B Permanent Magnets with APS Bending Magnet X-rays and 60 Co γ-rays J. Alderman and P.K. Job APS Operations Division Advanced Photon Source J. Puhl Ionizing Radiation Division National Institute of Standards and Technology June 2000 Table of Contents Introduction Radiation-Induced Demagnetization of Permanent Magnets Resources Required γ-ray Irradiation Results and Analysis of γ-ray Irradiation X-ray Irradiation Results and Analysis of X-ray Irradiation Summary and Conclusions Acknowledgements References Tables and Figures Introduction The Advanced Photon Source (APS), as well as other third-generation synchrotron light sources, uses permanent magnets in the insertion devices to produce x-rays for scientific

197

Gamma Ray Burst Central Engines  

E-Print Network (OSTI)

I review aspects of the theory of long-duration gamma-ray burst (GRB) central engines. I focus on the requirements of any model; these include the angular momentum of the progenitor, the power, Lorentz factor, asymmetry, and duration of the flow, and both the association and the non-association with bright supernovae. I compare and contrast the collapsar and millisecond proto-magnetar models in light of these requirements. The ability of the latter model to produce a flow with Lorentz factor ~100 while simultaneously maintaining a kinetic luminosity of ~10^50 ergs/s for a timescale of ~10-100 s is emphasized.

Todd A. Thompson

2008-07-04T23:59:59.000Z

198

High-energy Cosmic Rays  

E-Print Network (OSTI)

After a brief review of galactic cosmic rays in the GeV to TeV energy range, we describe some current problems of interest for particles of very high energy. Particularly interesting are two features of the spectrum, the `knee' above $10^{15}$ eV and the `ankle' above $10^{18}$ eV. An important question is whether the highest energy particles are of extra-galactic origin and, if so, at what energy the transition occurs. A theme common to all energy ranges is use of nuclear abundances as a tool for understanding the origin of the cosmic radiation.

Thomas K. Gaisser; Todor Stanev

2005-10-11T23:59:59.000Z

199

PHYSICAL PROCESSES SHAPING GAMMA-RAY BURST X-RAY AFTERGLOW LIGHT CURVES: THEORETICAL IMPLICATIONS FROM THE SWIFT X-RAY TELESCOPE OBSERVATIONS  

E-Print Network (OSTI)

PHYSICAL PROCESSES SHAPING GAMMA-RAY BURST X-RAY AFTERGLOW LIGHT CURVES: THEORETICAL IMPLICATIONS August 15; accepted 2005 December 19 ABSTRACT With the successful launch of the Swift Gamma-Ray Burst component is consistent with the tail emission of the prompt gamma-ray bursts and/or the X-ray flares

Zhang, Bing

200

Energetics of Gamma Ray Bursts  

E-Print Network (OSTI)

We determine the distribution of total energy emitted by gamma-ray bursts for bursts with fluences and distance information. Our core sample consists of eight bursts with BATSE spectra and spectroscopic redshifts. We extend this sample by adding four bursts with BATSE spectra and host galaxy R magnitudes. From these R magnitudes we calculate a redshift probability distribution; this method requires a model of the host galaxy population. From a sample of ten bursts with both spectroscopic redshifts and host galaxy R magnitudes (some do not have BATSE spectra) we find that the burst rate is proportional to the galaxy luminosity at the epoch of the burst. Assuming that the total energy emitted has a log-normal distribution, we find that the average emitted energy (assumed to be radiated isotropically) is $gamma iso} > = 1.3^{+1.2}_{-1.0} \\times 10^{53}$ ergs (for H$_0$ = 65 km s$^{-1}$ Mpc$^{-1}$, $\\Omega_m=0.3$ and $\\Omega_\\Lambda=0.7$); the distribution has a logarithmic width of $\\sigma_\\gamma=1.7^{+0.7}_{-0.3}$. The corresponding distribution of X-ray afterglow energy (for seven bursts) has $ = 4.0^{+1.6}_{-1.8} \\times 10^{51}$ergs and $\\sigma_X = 1.3^{+0.4}_{-0.3}$. For completeness, we also provide spectral fits for all bursts with BATSE spectra for which there were afterglow searches.

Raul Jimenez; David Band; Tsvi Piran

2001-03-16T23:59:59.000Z

Note: This page contains sample records for the topic "keynote ray mabus" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

X-ray data booklet. Revision  

SciTech Connect

A compilation of data is presented. Included are properties of the elements, electron binding energies, characteristic x-ray energies, fluorescence yields for K and L shells, Auger energies, energy levels for hydrogen-, helium-, and neonlike ions, scattering factors and mass absorption coefficients, and transmission bands of selected filters. Also included are selected reprints on scattering processes, x-ray sources, optics, x-ray detectors, and synchrotron radiation facilities. (WRF)

Vaughan, D. (ed.)

1986-04-01T23:59:59.000Z

202

X-ray transmissive debris shield  

DOE Patents (OSTI)

A composite window structure is described for transmitting x-ray radiation and for shielding radiation generated debris. In particular, separate layers of different x-ray transmissive materials are laminated together to form a high strength, x-ray transmissive debris shield which is particularly suited for use in high energy fluences. In one embodiment, the composite window comprises alternating layers of beryllium and a thermoset polymer.

Spielman, Rick B. (Albuquerque, NM)

1994-01-01T23:59:59.000Z

203

Black Stars and Gamma Ray Bursts  

E-Print Network (OSTI)

Stars that are collapsing toward forming a black hole but are frozen near the Schwarzschild horizon are termed ``black stars''. Collisions of black stars, in contrast to black hole collisions, may be sources of gamma ray bursts, whose basic parameters are estimated quite simply and are found to be consistent with observed gamma ray bursts. Black star gamma ray bursts should be preceded by gravitational wave emission similar to that from the coalescence of black holes.

Tanmay Vachaspati

2007-06-08T23:59:59.000Z

204

NIST X-Ray Transition Energies  

Science Conference Proceedings (OSTI)

... with the International System of measurement ... titled "X-ray transition energies: new approach ... and by NIST's Systems Integration for Manufacturing ...

2011-12-09T23:59:59.000Z

205

X-ray Line Profile Analysis  

Science Conference Proceedings (OSTI)

... Magnetic Composite Materials X-Ray Studies of Structural Effects Induced by Pulsed (30 Tesla), High Magnetic Fields at the Advanced Photon Source...

206

NIST: X-Ray Mass Attenuation Coefficients  

Science Conference Proceedings (OSTI)

... NIST reserves the right to charge for these data in the ... ?/? and the mass energy-absorption coefficient ... The tables cover energies of the photon (x-ray ...

2011-12-09T23:59:59.000Z

207

Lensless X-Ray Imaging in Reflection  

NLE Websites -- All DOE Office Websites (Extended Search)

relevant to atomic and molecular phenomena) with the advantages of visible-light lasers (highly coherent beams). All of these characteristics are important for coherent x-ray...

208

Gamma ray burst outflows and afterglows.  

E-Print Network (OSTI)

?? We carry out a theoretical investigation of jet propagation in Gamma Ray Bursts and examine the jitter radiation mechanism as a means of producing (more)

Morsony, Brian J.

2009-01-01T23:59:59.000Z

209

High-energy cosmic ray interactions  

SciTech Connect

Research into hadronic interactions and high-energy cosmic rays are closely related. On one hand--due to the indirect observation of cosmic rays through air showers--the understanding of hadronic multiparticle production is needed for deriving the flux and composition of cosmic rays at high energy. On the other hand the highest energy particles from the universe allow us to study the characteristics of hadronic interactions at energies far beyond the reach of terrestrial accelerators. This is the summary of three introductory lectures on our current understanding of hadronic interactions of cosmic rays.

Engel, Ralph [Forschungszentrum Karlsruhe, P.O. Box 3640, 76021 Karlsruhe (Germany); Orellana, Mariana [Instituto Argentino de Radioastronomia (IAR), CCT La Plata (CONICET), C.C.5, 1894 Villa Elisa, Buenos Aires (Argentina); Facultad de Ciencias Astronomicas y Geofisicas, Universidad Nacional de La Plata, Paseo del Bosque, 1900 La Plata (Argentina); Reynoso, Matias M. [Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Funes 3350, (7600) Mar del Plata (Argentina); Instituto de Investigaciones Fisicas de Mar del Plata, (UNMdP-CONICET) (Argentina); Vila, Gabriela S. [Instituto Argentino de Radioastronomia (IAR), CCT La Plata (CONICET), C.C.5, 1894 Villa Elisa, Buenos Aires (Argentina)

2009-04-30T23:59:59.000Z

210

VHE Gamma-ray Supernova Remnants  

SciTech Connect

Increasing observational evidence gathered especially in X-rays and {gamma}-rays during the course of the last few years support the notion that Supernova remnants (SNRs) are Galactic particle accelerators up to energies close to the ''knee'' in the energy spectrum of Cosmic rays. This review summarizes the current status of {gamma}-ray observations of SNRs. Shell-type as well as plerionic type SNRs are addressed and prospect for observations of these two source classes with the upcoming GLAST satellite in the energy regime above 100 MeV are given.

Funk, Stefan; /KIPAC, Menlo Park

2007-01-22T23:59:59.000Z

211

Search for gamma ray burst counterparts  

Science Conference Proceedings (OSTI)

The confident detection of a Gamma Ray Burst counterpart would likely provide the much needed breakthrough in our understanding of the cause and site of bursts. As such

Bradley E. Schaefer

1994-01-01T23:59:59.000Z

212

Hard X-Ray Quad Collimator  

Technology Development and Commercialization Division One of the best ways to obtain small?size x?ray beams for structural biology research is to ...

213

Gamma-Ray Bursts and Particle Astrophysics  

E-Print Network (OSTI)

Gamma-ray bursts are violent events occurring randomly in the sky. In this review, I will present the fireball model, proposed to explain the phenomenon of gamma-ray bursts. This model has important consequences for the production and observation at Earth of gravitational waves, high energy neutrinos, cosmic rays and high energy photons, and the second part of this review will be focused on these aspects. A last section will briefly discuss the topic of the use of gamma-ray bursts as standard candles and possible cosmological studies.

B. Gendre

2008-07-24T23:59:59.000Z

214

X?ray Fluorescence (XRF) Assay Using Laser Compton Scattered (LCS) X?rays  

Science Conference Proceedings (OSTI)

Laser Compton Scattered (LCS) X?rays are produced as a result of the interaction between accelerated electrons and a laser beam. The yield of LCS X?rays is dependent on the laser power

Syed F. Naeem; Khalid Chouffani; Douglas P. Wells

2009-01-01T23:59:59.000Z

215

X-ray spectroscopy of neutron star low-mass X-ray binaries  

E-Print Network (OSTI)

In this thesis, I present work spanning a variety of topics relating to neutron star lowmass X-ray binaries (LMXBs) and utilize spectral information from X-ray observations to further our understanding of these sources. ...

Krauss, Miriam Ilana

2007-01-01T23:59:59.000Z

216

X-Ray Multilayer Database from the LBL Center for X-Ray Optics (CXRO)  

DOE Data Explorer (OSTI)

An important activity of the Center for X-ray Optics (CXRO) is research on x-ray mirrors and their use in optical devices to focus and deflect x-ray beams. The two kinds of mirrors most widely used are glancing incidence reflectors and multilayer coatings. The X-Ray Multilayer Database is based on the results of surveys taken at the biennial Physics of X-Ray Multilayer Structures conferences. It contains measured x-ray reflectances reported for various multilayers. The database is provided as a service to the x-ray and multilayer research communities and is intended to reflect the state-of-the-art in multilayer x-ray mirrors. (Specialized Interface)

217

Gamma-Ray Pulsar Visibility  

E-Print Network (OSTI)

PSR J0437-4715 is a millisecond pulsar (MSP) thought to be ``pair formation starved'' (having limited pair cascades due to magnetic photon absorption). Fortunately the general relativistic (GR) electrodynamical model under consideration applicable to this pulsar have few free parameters. We model PSR J0437-4715's visibility, using a 3D model which incorporates the variation of the GR E-field over the polar cap (PC), taking different observer and inclination angles into account. Using this pulsar as a case study, one may generalize to conducting a pulsar population visibility study. We lastly comment on the role of the proposed South African SKA (Square Kilometre Array) prototype, KAT (Karoo Array Telescope), for GLAST gamma-ray pulsar identification.

Venter, C

2005-01-01T23:59:59.000Z

218

Gamma-Ray Pulsar Visibility  

E-Print Network (OSTI)

PSR J0437-4715 is a millisecond pulsar (MSP) thought to be ``pair formation starved'' (having limited pair cascades due to magnetic photon absorption). Fortunately the general relativistic (GR) electrodynamical model under consideration applicable to this pulsar have few free parameters. We model PSR J0437-4715's visibility, using a 3D model which incorporates the variation of the GR E-field over the polar cap (PC), taking different observer and inclination angles into account. Using this pulsar as a case study, one may generalize to conducting a pulsar population visibility study. We lastly comment on the role of the proposed South African SKA (Square Kilometre Array) prototype, KAT (Karoo Array Telescope), for GLAST gamma-ray pulsar identification.

C. Venter; O. C. de Jager; A. Tiplady

2005-10-14T23:59:59.000Z

219

Gamma-Ray Pulsar Visibility  

E-Print Network (OSTI)

Abstract. PSR J0437-4715 is a millisecond pulsar (MSP) thought to be pair formation starved (having limited pair cascades due to magnetic photon absorption). Fortunately the general relativistic (GR) electrodynamical model under consideration applicable to this pulsar have few free parameters. We model PSR J0437-4715s visibility [1], using a 3D model which incorporates the variation of the GR E-field over the polar cap (PC), taking different observer and inclination angles into account. Using this pulsar as a case study, one may generalize to conducting a pulsar population visibility study. We lastly comment on the role of the proposed South African SKA (Square Kilometre Array) prototype, KAT (Karoo Array Telescope), for GLAST ?-ray pulsar identification.

Christo Venter; Ocker C. De Jager; Adrian Tiplady

2005-01-01T23:59:59.000Z

220

Gamma Ray Bursts Cannot Produce the Observed Cosmic Rays Above 10 19 eV  

E-Print Network (OSTI)

Received; accepted 2 Using recent results indicating that the redshift distribution of ?-ray bursts most likely follows the redshift evolution of the star formation rate, I show that the energy input from these bursts at low redshifts is insufficient to account for the observed flux of ultrahigh energy cosmic rays with energies above 1019 eV. Subject Headings: gamma-rays: bursts cosmic rays: theory 3 1.

F. W. Stecker

1999-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "keynote ray mabus" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Materials Analysis by Soft x-ray Scanning Transmission X-ray ...  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, Materials Science & Technology 2013. Symposium, Optical and X-ray Imaging Techniques for Material Characterization.

222

Ultrahigh Energy Cosmic Rays from Gamma Ray Bursts: Implications of the Recent Observational Results by Milagro  

E-Print Network (OSTI)

It has been speculated earlier that Gamma Ray Bursts are sources of ultrahigh energy cosmic rays. Recently, the search for high energy photons from Gamma Ray Bursts by Milagro group has put limits on the isotropic luminosity of these transient sources in very high energy photons. The implications of the results obtained by Milagro to our understanding of the ultrahigh energy cosmic ray spectrum from these sources have been discussed in the present work.

Nayantara Gupta

2004-06-03T23:59:59.000Z

223

ON THE RECENTLY DISCOVERED CORRELATIONS BETWEEN GAMMA-RAY AND X-RAY PROPERTIES OF GAMMA-RAY BURSTS  

SciTech Connect

Recently, many correlations between the prompt {gamma}-ray emission properties and the X-ray afterglow properties of gamma-ray bursts (GRBs) have been inferred from a comprehensive analysis of the X-ray light curves of more than 650 GRBs measured with the Swift X-Ray Telescope (Swift/XRT) during the years 2004-2010. We show that these correlations are predicted by the cannonball (CB) model of GRBs. They result from the dependence of GRB observables on the bulk motion Lorentz factor and viewing angle of the jet of highly relativistic plasmoids (CBs) that produces the observed radiations by interaction with the medium through which it propagates. Moreover, despite their different physical origins, long GRBs (LGRBs) and short-hard bursts (SHBs) in the CB model share similar kinematic correlations, which can be combined into triple correlations satisfied by both LGRBs and SHBs.

Dado, Shlomo; Dar, Arnon [Physics Department, Technion, Haifa 32000 (Israel)

2013-09-20T23:59:59.000Z

224

Gravitational Waves versus X and Gamma Ray Emission in a Short Gamma-Ray Burst  

E-Print Network (OSTI)

The recent progress in the understanding the physical nature of neutron star equilibrium configurations and the first observational evidence of a genuinely short gamma-ray burst, GRB 090227B, allows to give an estimate of the gravitational waves versus the X and Gamma ray emission in a short gamma-ray burst.

F. G. Oliveira; Jorge A. Rueda; Remo Ruffini

2012-05-31T23:59:59.000Z

225

Gamma-Rays from Grazing Incidence Cosmic Rays in the Earths Atmosphere  

E-Print Network (OSTI)

Interactions of grazing incidence, ultra high energy cosmic rays with the earths atmosphere may provide a new method of studying energetic cosmic rays with gamma-ray satellites. It is found that these cosmic ray interactions may produce gamma-rays on millisecond time scales which may be detectable by satellites. An extremely low gamma-ray background for transient gamma-ray events and a large area of interaction, the earths surface, make the scheme plausible. The effective cross section of detection of interactions for cosmic rays above 1020 eV is found to be more than two orders of magnitude higher than earth based detection techniques. This method may eventually offer an efficient way of probing this region of the cosmic ray energy spectrum where events are scarce. In this paper, a conceptual model is presented for the production of short bursts of gamma-rays based on these grazing incidence encounters with the earths atmosphere. Subject headings: atmospheric effects- cosmic rays- Earth- gamma-rays: bursts

Andrew Ulmer

1994-01-01T23:59:59.000Z

226

The Universe Viewed in Gamma-Rays 1 Properties of Gamma-ray Bursts Localized by  

E-Print Network (OSTI)

The short gamma-ray burst ­ SGR giant flare connection Kevin Hurley University of California cosmic gamma-ray bursts. There are at least two general ways to approach this problem. One is statistical short gamma-ray bursts (GRBs) could actually be extragalactic giant magnetar flares is not new by any

Enomoto, Ryoji

227

Are extragalactic gamma ray bursts the source of the highest energy cosmic rays?  

E-Print Network (OSTI)

Recent observations with the large air shower arrays of ultra high energy cosmic rays (UHECR) and recent measurements/estimates of the redshifts of gamma ray bursts (GRBs) seem to rule out extragalactic GRBs as the source of the cosmic rays that are observed near Earth, including those with the highest energies.

Arnon Dar

1999-01-03T23:59:59.000Z

228

Lithium-6 and Gamma Rays: Complementary Constraints on Cosmic-Ray History  

E-Print Network (OSTI)

The rare isotope 6Li is made only by cosmic rays, dominantly in alpha+alpha fusion reactions with ISM helium. Consequently, this nuclide provides a unique diagnostic of the history of cosmic rays in our Galaxy. The same hadronic cosmic-ray interactions also produce high-energy gamma rays (mostly via neutral pion production). Thus, hadronic gamma-rays and 6Li are intimately linked. Specifically, 6Li directly encodes the local cosmic-ray fluence over cosmic time, while extragalactic hadronic gamma rays encode an average cosmic-ray fluence over lines of sight out to the horizon. We examine this link and show how 6Li and gamma-rays can be used together to place important model-independent limits on the cosmic-ray history of our Galaxy and the universe. We first constrain gamma-ray production from ordinary Galactic cosmic rays, using the local 6Li abundance. We find that the solar 6Li abundance demands an accompanying extragalactic pionic gamma-ray intensity which exceeds that of the entire observed EGRB by a factor of 2-6. Possible explanations for this discrepancy are discussed. We then constrain Li production using recent determinations of extragalactic gamma-ray background (EGRB). We note that cosmic rays created during cosmic structure formation would lead to pre-Galactic Li production, which would act as a "contaminant" to the primordial 7Li content of metal-poor halo stars. We find the uncertainties in the observed EGRB are so large that we cannot exclude a pre-Galactic Li which is comparable to primordial 7Li. Our limits and their more model-dependent extensions will improve significantly with additional observations of 6Li in halo stars, and with improved measurements of the EGRB spectrum by GLAST. (Abriged abstract)

Brian D. Fields; Tijana Prodanovic

2004-07-15T23:59:59.000Z

229

Gamma-Ray Pulsar Studies with GLAST  

E-Print Network (OSTI)

Some pulsars have their maximum observable energy output in the gamma-ray band, offering the possibility of using these high-energy photons as probes of the particle acceleration and interaction processes in pulsar magnetospheres. After an extended hiatus between satellite missions, the recently-launched AGILE mission and the upcoming Gamma-ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT) will allow gamma-ray tests of the theoretical models developed based on past discoveries. With its greatly improved sensitivity, better angular resolution, and larger energy reach than older instruments, GLAST LAT should detect dozens to hundreds of new gamma-ray pulsars and measure luminosities, light curves, and phase-resolved spectra with unprecedented resolution. It will also have the potential to find radio-quiet pulsars like Geminga, using blind search techniques. Cooperation with radio and X-ray pulsar astronomers is an important aspect of the LAT team's planning for pulsar studies.

D. J. Thompson

2007-11-27T23:59:59.000Z

230

Gamma-Ray Pulsar Studies With GLAST  

SciTech Connect

Some pulsars have their maximum observable energy output in the gamma-ray band, offering the possibility of using these high-energy photons as probes of the particle acceleration and interaction processes in pulsar magnetospheres. After an extended hiatus between satellite missions, the recently-launched AGILE mission and the upcoming Gamma-ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT) will allow gamma-ray tests of the theoretical models developed based on past discoveries. With its greatly improved sensitivity, better angular resolution, and larger energy reach than older instruments, GLAST LAT should detect dozens to hundreds of new gamma-ray pulsars and measure luminosities, light curves, and phase-resolved spectra with unprecedented resolution. It will also have the potential to find radio-quiet pulsars like Geminga, using blind search techniques. Cooperation with radio and X-ray pulsar astronomers is an important aspect of the LAT team's planning for pulsar studies.

Thompson, D.J.; /NASA, Goddard

2011-11-23T23:59:59.000Z

231

Results from the Milagro Gamma-Ray Observatory  

E-Print Network (OSTI)

V energies, and a search for transient emission above 100 GeV from gamma-ray bursts. 1 Introduction remnants and gamma-ray bursts (GRB). Gamma rays are also produced when high-energy cosmic rays interactResults from the Milagro Gamma-Ray Observatory E. Blaufuss for the Milagro Collaboration a,1 , a

California at Santa Cruz, University of

232

ON THE X-RAY OUTBURSTS OF TRANSIENT ANOMALOUS X-RAY PULSARS AND SOFT GAMMA-RAY REPEATERS  

SciTech Connect

We show that the X-ray outburst light curves of four transient anomalous X-ray pulsars (AXPs) and soft gamma-ray repeaters (SGRs), namely, XTE J1810-197, SGR 0501+4516, SGR 1627-41, and CXOU J164710.2-455216, can be produced by the fallback disk model that was also applied to the outburst light curves of persistent AXPs and SGRs in our earlier work. The model solves the diffusion equation for the relaxation of a disk that has been pushed back by a soft gamma-ray burst. The sets of main disk parameters used for these transient sources are very similar to each other and to those employed in our earlier models of persistent AXPs and SGRs. There is a characteristic difference between the X-ray outburst light curves of transient and persistent sources. This can be explained by the differences in the disk surface density profiles of the transient and persistent sources in quiescence indicated by their quiescent X-ray luminosities. Our results imply that a viscous disk instability operating at a critical temperature in the range of {approx}1300-2800 K is a common property of all fallback disks around AXPs and SGRs. The effect of the instability is more pronounced and starts earlier for the sources with lower quiescent luminosities, which leads to the observable differences in the X-ray enhancement light curves of transient and persistent sources. A single active disk model with the same basic disk parameters can account for the enhancement phases of both transient and persistent AXPs and SGRs. We also present a detailed parameter study to show the effects of disk parameters on the evolution of the X-ray luminosity of AXPs and SGRs in the X-ray enhancement phases.

Cal Latin-Small-Letter-Dotless-I skan, Sirin; Ertan, Uenal [Sabanc Latin-Small-Letter-Dotless-I University, Orhanl Latin-Small-Letter-Dotless-I -Tuzla, Istanbul, 34956 (Turkey)

2012-10-20T23:59:59.000Z

233

GRB 050117: SIMULTANEOUS GAMMA-RAY AND X-RAY OBSERVATIONS WITH THE SWIFT SATELLITE Joanne E. Hill,1, 2  

E-Print Network (OSTI)

The Swift Gamma-Ray Burst Explorer performed its first autonomous, X-ray follow-up to a newly detected GRB from the XRT position. Subject headingg: gamma rays: bursts 1. INTRODUCTION The Swift Gamma-ray Burst Explorer (Gehrels et al. 2004) was launched on 2004 November 20 to study gamma-ray bursts (GRBs) over

Zhang, Bing

234

CONSTRAINTS ON VERY HIGH ENERGY GAMMA-RAY EMISSION FROM GAMMA-RAY BURSTS R. Atkins,1,2  

E-Print Network (OSTI)

CONSTRAINTS ON VERY HIGH ENERGY GAMMA-RAY EMISSION FROM GAMMA-RAY BURSTS R. Atkins,1,2 W. Benbow,3 emission from gamma-ray bursts (GRBs) during the prompt emission phase. Detection of >100 GeV counterparts on potential GRB models. Subject headinggs: gamma rays: bursts -- gamma rays: observations 1. INTRODUCTION

California at Santa Cruz, University of

235

Lensless X-Ray Imaging in Reflection  

NLE Websites -- All DOE Office Websites (Extended Search)

Lensless X-Ray Imaging in Lensless X-Ray Imaging in Reflection Lensless X-Ray Imaging in Reflection Print Wednesday, 26 October 2011 00:00 The advent of x-ray free-electron laser (XFEL) light sources has led to an outburst of research activities in the field of lensless imaging. XFELs combine the advantages of sychrotron light sources (high brightness and x-ray wavelengths relevant to atomic and molecular phenomena) with the advantages of visible-light lasers (highly coherent beams). All of these characteristics are important for coherent x-ray diffraction imaging-lensless imaging techniques that are proving to be integral to single-shot, high-resolution imaging of both complex materials and biological samples. Existing techniques are typically designed for transmission geometry, however, and use isolated objects, requiring special sample fabrication and restricting the type of samples under investigation. Recently, researchers from the ALS and the University of Oregon have shown at ALS Beamline 12.0.2 that it is possible to form x-ray holograms in reflection geometry by using the light scattered from a sample, opening the door to lensless imaging of a wealth of new material samples.

236

Gamma-Ray Burst Physics with GLAST  

SciTech Connect

The Gamma-ray Large Area Space Telescope (GLAST) is an international space mission that will study the cosmos in the energy range 10 keV-300 GeV, the upper end of which is one of the last poorly observed region of the celestial electromagnetic spectrum. The ancestor of the GLAST/LAT was the Energetic Gamma Ray Experiment Telescope (EGRET) detector, which flew onboard the Compton Gamma Ray Observatory (CGRO). The amount of information and the step forward that the high energy astrophysics made thanks to its 9 years of observations are impressive. Nevertheless, EGRET uncovered the tip of the iceberg, raising many questions, and it is in the light of EGRET's results that the great potential of the next generation gamma-ray telescope can be appreciated. GLAST will have an imaging gamma-ray telescope, the Large Area Telescope (LAT) vastly more capable than instruments own previously, as well as a secondary instrument, the GLAST Bursts Monitor, or GBM, to augment the study of gamma-ray bursts. Gamma-Ray Bursts (GRBs) science is one of the most exciting challenges for the GLAST mission, exploring the high energy emission of one of the most intense phenomena in the sky, shading light on various problems: from the acceleration of particles to the emission processes, to more exotic physics like Quantum Gravity effect. In this paper we report the work done so far in the simulation development as well as the study of the LAT sensitivity to GRB.

Omodei, N.; /INFN, Pisa

2006-10-06T23:59:59.000Z

237

Gamma-ray albedo of the moon  

E-Print Network (OSTI)

We use the GEANT4 Monte Carlo framework to calculate the gamma-ray albedo of the Moon due to interactions of cosmic ray (CR) nuclei with moon rock. Our calculation of the albedo spectrum agrees with the EGRET data. We show that the spectrum of gamma rays from the Moon is very steep with an effective cutoff around 4 GeV (600 MeV for the inner part of the Moon disc). Apart from other astrophysical sources, the albedo spectrum of the Moon is well understood, including its absolute normalisation; this makes it a useful "standard candle" for gamma-ray telescopes, such as the forthcoming Gamma Ray Large Area Space Telescope (GLAST). The albedo flux depends on the incident CR spectrum which changes over the solar cycle. Therefore, it is possible to monitor the CR spectrum using the albedo gamma-ray flux. Simultaneous measurements of CR proton and helium spectra by the Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA), and observations of the albedo gamma rays by the GLAST Large Area Telescope (LAT), can be used to test the model predictions and will enable the GLAST LAT to monitor the CR spectrum near the Earth beyond the lifetime of PAMELA.

Igor V. Moskalenko; Troy A. Porter

2007-05-25T23:59:59.000Z

238

X-Ray Scattering Group, Condensed Matter Physics & Materials...  

NLE Websites -- All DOE Office Websites (Extended Search)

- Brookhaven National Laboratory, Upton, NY Beamline X1A2 - Soft x-ray diffraction and nano-imaging Beamline X17 - X-ray powder diffraction Beamline X22C - Resonant x-ray...

239

Observations of Gamma-Ray Bursts at Extreme Energies  

E-Print Network (OSTI)

of Gamma-Ray Bursts . . . . . . . . . . . . . Redshift-CRUZ OBSERVATIONS OF GAMMA-RAY BURSTS AT EXTREME ENERGIES ADedication xix Acknowledgments xx 1 Gamma-Ray Bursts 1.1

Aune, Taylor

2012-01-01T23:59:59.000Z

240

Fireball/Blastwave Model and Soft Gamma-ray Repeaters  

E-Print Network (OSTI)

Soft gamma-ray repeaters are at determined distances and their positions are known accurately. If observed, afterglows from their soft gamma-ray bursts will provide important clues to the study of the so called "classical gamma-ray bursts". On applying the popular fireball/blastwave model of classical gamma-ray bursts to soft gamma-ray repeaters, it is found that their X-ray and optical afterglows are detectable. Monitoring of the three repeaters is solicited.

Y. F. Huang; Z. G. Dai; T. Lu

1998-10-28T23:59:59.000Z

Note: This page contains sample records for the topic "keynote ray mabus" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

DOE - Office of Legacy Management -- Exxon Ray Point Site - 032  

Office of Legacy Management (LM)

Exxon Ray Point Site - 032 FUSRAP Considered Sites Site: Exxon Ray Point Site (032) Designated Name: Alternate Name: Location: Evaluation Year: Site Operations: Site Disposition:...

242

Studies of meutron star X-ray binaries  

E-Print Network (OSTI)

by type I bursts or gamma-ray bursts (GRBs), produce aspread function (PSF). Gamma-ray bursts produce a similar

Thompson, Thomas W. J.

2008-01-01T23:59:59.000Z

243

Copper Ridges Nearly Double X-ray Sensor Performance  

Science Conference Proceedings (OSTI)

... Physics Letters,* can measure X-ray energies with an ... X-rays and measure the energy based on ... by NASA and the NIST Office of Microelectronics ...

2011-10-03T23:59:59.000Z

244

SLAC National Accelerator Laboratory - Fermi's Latest Gamma-ray...  

NLE Websites -- All DOE Office Websites (Extended Search)

Fermi's Latest Gamma-ray Census Highlights Cosmic Mysteries By Francis Reddy, NASAGoddard Space Flight Center September 9, 2011 Every three hours, NASA's Fermi Gamma-ray Space...

245

Sandia National Laboratories X-ray Tube with Magnetic Electron ...  

... for the U.S. Department of Energys National ... high average power large area X-ray tube provides increased X-ray generation efficiency through ...

246

Inelastic X-ray and Nuclear Resonant Scattering  

NLE Websites -- All DOE Office Websites (Extended Search)

Beamlines Divisions Argonne Home > Advanced Photon Source > Inelastic X-ray and Nuclear Resonant Scattering The Inelastic X-ray and Nuclear Resonant Scattering group...

247

POLARIX: a pathfinder mission of X-ray polarimetry  

Science Conference Proceedings (OSTI)

Compton gamma-ray polarimetry resulted in the very debated measurement of some bright gamma-ray bursts [6, 7], and in the measurement of the polarization

248

Mining Gamma-Ray Burst Data  

E-Print Network (OSTI)

Gamma-ray bursts provide what is probably one of the messiest of all astrophysical data sets. Burst class properties are indistinct, as overlapping characteristics of individual bursts are convolved with effects of instrumental and sampling biases. Despite these complexities, data mining techniques have allowed new insights to be made about gamma-ray burst data. We demonstrate how data mining techniques have simultaneously allowed us to learn about gamma-ray burst detectors and data collection, cosmological effects in burst data, and properties of burst subclasses. We discuss the exciting future of this field, and the web-based tool we are developing (with support from the NASA AISR Program). We invite others to join us in AI-guided gamma-ray burst classification (http://grb.mnsu.edu/grb/).

Jon Hakkila; Richard J. Roiger; David J. Haglin; Robert S. Mallozzi; Geoffrey N. Pendleton; Charles A. Meegan

2000-11-30T23:59:59.000Z

249

Gravitational waves and gamma-ray bursts  

E-Print Network (OSTI)

Gamma-Ray Bursts are likely associated with a catastrophic energy release in stellar mass objects. Electromagnetic observations provide important, but indirect information on the progenitor. On the other hand, gravitational waves emitted from the central source, carry direct information on its nature. In this context, I give an overview of the multi-messenger study of gamma-ray bursts that can be carried out by using electromagnetic and gravitational wave observations. I also underline the importance of joint electromagnetic and gravitational wave searches, in the absence of a gamma-ray trigger. Finally, I discuss how multi-messenger observations may probe alternative gamma-ray burst progenitor models, such as the magnetar scenario.

Alessandra Corsi; for the LIGO Scientific Collaboration; for the Virgo Collaboration

2012-04-18T23:59:59.000Z

250

Are High Energy Cosmic Rays Magnetic Monopoles?  

E-Print Network (OSTI)

We argue that magnetic monopoles can not be associated to the highest energy cosmic rays as recently suggested. Both the observed spectrum and the arrival direction disagree with observation.

C. O. Escobar; R. A. Vzquez

1997-09-15T23:59:59.000Z

251

High-Resolution X-ray Spectroscopy  

Science Conference Proceedings (OSTI)

... In support of these efforts, we also maintain laboratory x-ray sources from 1 keV to 300 keV, energy and intensity calibration facilities, and a vacuum ...

2013-02-26T23:59:59.000Z

252

Accelerating ray tracing using constrained tetrahedralizations  

Science Conference Proceedings (OSTI)

In this paper we introduce the constrained tetrahedralization as a new acceleration structure for ray tracing. A constrained tetrahedralization of a scene is a tetrahedralization that respects the faces of the scene geometry. The closest intersection ...

Ares Lagae; Philip Dutr

2008-06-01T23:59:59.000Z

253

X-ray image intensifier phosphor  

DOE Patents (OSTI)

Y/sub 1-x/Gd/sub x/.PO$sub 4$:Tb$sup 3+$ is an effective phosphor for use in X-ray intensifier screens and in nuclear radiation detection systems.

D' Silva, A.P.; Fassel, V.A.

1975-12-01T23:59:59.000Z

254

Kaonic Atom X?ray Spectra  

Science Conference Proceedings (OSTI)

In kaonic atoms energy displacement and broadening of states result from the strong interaction. The most simple kaonic atoms like kaonic hydrogen and deuterium open the possibility to measure this strong interaction induced shift and width by x?ray spectroscopy. In the SIDDHARTA experiment al LNF (Frascati) the DA?NE electron?positron collider delivers nearly mono?energetic negatively charged kaons from ? meson decay. This unique kaon source is used to form kaonic atoms. New high performance x?ray detectors (silicon drift detectors) arranged in an array allow x?ray spectroscopy with high energy resolution combined with timing capability. High precision x?ray measurements like SIDDHARTA at LNF will open the way to study the low energy regime of the strong force in the antikaon?nucleon interaction. The experiment and its current status is presented in this talk.

J. Marton; on behalf of the SIDDHARTA Collaboration

2009-01-01T23:59:59.000Z

255

Ray-tracing Procedural Displacement Shaders  

E-Print Network (OSTI)

Displacement maps and procedural displacement shaders are a widely used approach of specifying geometric detail and increasing the visual complexity of a scene. While it is relatively straightforward to handle displacement shaders in pipeline based rendering systems such as the Reyes-architecture, it is much harder to efficiently integrate displacement-mapped surfaces in ray-tracers. Many commercial ray-tracers tessellate the surface into a multitude of small triangles. This introduces a series of problems such as excessive memory consumption and possibly undetected surface detail. In this paper we describe a novel way of ray-tracing procedural displacement shaders directly, that is, without introducing intermediate geometry. Affine arithmetic is used to compute bounding boxes for the shader over any range in the parameter domain. The method is comparable to the direct ray-tracing of B'ezier surfaces and implicit surfaces using B'ezier clipping and interval methods, respectively. Keyw...

Wolfgang Heidrich; Hans-peter Seidel

1998-01-01T23:59:59.000Z

256

Gravitational waves and short gamma ray bursts.  

E-Print Network (OSTI)

??Short hard gamma-ray bursts (GRB) are believed to be produced by compact binary coalescences (CBC) { either double neutron stars or neutron star{black hole binaries. (more)

Predoi, Valeriu

2012-01-01T23:59:59.000Z

257

Cosmic ray propagation in galactic turbulence  

E-Print Network (OSTI)

We revisit propagation of galactic cosmic rays in light of recent advances in cosmic ray diffusion theory in realistic interstellar turbulence. We use tested model of turbulence in which it has been shown that fast modes dominate scattering of cosmic rays. As a result, propagation becomes inhomogeneous and environment dependent. By adopting the formalism of the nonlinear theory (NLT) developed by Yan & Lazarian (2008), we calculate diffusion of cosmic rays self-consistently from first principles. We assume a two-phase model for the Galaxy to account for different damping mechanisms of the fast modes, and we find that the energy dependence of the diffusion coefficient is mainly affected by medium properties. We show that it gives a correct framework to interpret some of the recent CR puzzles.

Evoli, Carmelo

2013-01-01T23:59:59.000Z

258

World's First Hard X-ray Laser  

NLE Websites -- All DOE Office Websites (Extended Search)

LCLS is the world's most powerful X-ray laser. Its highly focused beam, which arrives in staccato bursts a few quadrillionths of a second long, allows researchers to probe complex,...

259

Diffuse gamma-rays from galactic halos  

E-Print Network (OSTI)

Here we review our current knowledge on diffuse gamma-rays from galactic halos. Estimates of the relative contribution of the various emission processes at low and high latitudes are compared to the data over 6 decades in energy. The observed spectral shape differs from what was expected, especially at ver low and very high energies. In the latter case, above 1 GeV, the sky emission related to gas exceeds the expected pi^0 decay spectrum. At energies below 1 MeV the relatively high gamma-ray intensity indicates at high density of nearly relativistic electrons which would have a strong influence on the energy and ionisation balance of the interstellar medium. Given the EGRET results for the Magellanic Clouds the gamma-ray emissivity in the outer halo is probably small, so that a substantial amount of baryonic dark matter may be hidden at 20-50 kpc radius without inducing observable gamma-ray emission.

M. Pohl

1996-03-12T23:59:59.000Z

260

X-ray grid-detector apparatus  

DOE Patents (OSTI)

A hybrid grid-detector apparatus for x-ray systems wherein a microchannel plate structure has an air-interspaced grid portion and a phosphor/optical fluid-filled grid portion. The grids are defined by multiple adjacent channels separated by lead-glass septa. X-rays entering the air-interspaced grid portion at an angle of impingement upon the septa are attenuated, while non-impinging x-rays pass through to the phosphor/fluid filled portion. X-ray energy is converted to luminescent energy in the phosphor/fluid filled portion and the resultant beams of light are directed out of the phosphor/optical fluid filled portion to an imaging device.

Boone, John M. (Folsom, CA); Lane, Stephen M. (Oakland, CA)

1998-01-27T23:59:59.000Z

Note: This page contains sample records for the topic "keynote ray mabus" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Observations of Gamma Ray Bursts with AGILE  

E-Print Network (OSTI)

The AGILE satellite, in orbit since 2007, localized up to October 2009 about 1 Gamma Ray Burst (GRB) per month with the hard X-ray imager SuperAGILE (18 - 60 keV) (with a rate reduced by a factor 2-3 in spinning mode) and is detecting around 1 GRB per week with the non-imaging Mini-Calorimeter (MCAL, 0.35 - 100 MeV). Up to October 2011 the AGILE Gamma Ray Imaging Detector firmly detected four GRBs in the energy band between 20 MeV and few GeV. In this paper we review the status of the GRBs observation with AGILE and discuss the upper limits in the gamma-ray band of the non-detected events.

Longo, F; Del Monte, E; Marisaldi, M; Fuschino, F; Giuliani, A

2011-01-01T23:59:59.000Z

262

X-Ray Nanoimaging: Instruments and Methods  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Nanoimaging: Instruments and Methods To be held as part of SPIE. http:spie.orgOP318 August 28-29, 2013; San Diego, California, USA...

263

Can gamma-ray bursts constrain quintessence?  

E-Print Network (OSTI)

Using the narrow clustering of the geometrically corrected gamma-ray energies released by gamma-ray bursts, we investigate the possibility of using these sources as standard candles to probe cosmological parameters such as the matter density Omega_m and the cosmological constant energy density Omega_Lambda. By simulating different samples of gamma-ray bursts, we find that Omega_m can be determined with accuracy ~7% with data from 300 sources. We also show that, if Omega = 1 is due to a quintessence field, some of the models proposed in the literature may be discriminated from a Universe with cosmological constant, by a similar-sized sample of gamma-ray bursts.

T. Di Girolamo; R. Catena; M. Vietri; G. Di Sciascio

2005-04-27T23:59:59.000Z

264

Gamma Ray Bursts from Ordinary Cosmic Strings  

E-Print Network (OSTI)

We give an upper estimate for the number of gamma ray bursts from ordinary (non-superconducting) cosmic strings expected to be observed at terrestrial detectors. Assuming that cusp annihilation is the mechanism responsible for the bursts we consider strings arising at a GUT phase transition and compare our estimate with the recent BATSE results. Further we give a lower limit for the effective area of future detectors designed to detect the cosmic string induced flux of gamma ray bursts.

R. H. Brandenberger; A. T. Sornborger; M. Trodden

1993-02-12T23:59:59.000Z

265

X-Ray Emission from Compact Sources  

SciTech Connect

This paper presents a review of the physical parameters of neutron stars and black holes that have been derived from X-ray observations. I then explain how these physical parameters can be used to learn about the extreme conditions occurring in regions of strong gravity, and present some recent evidence for relativistic effects seen in these systems. A glossary of commonly used terms and a short tutorial on the names of X-ray sources are also included.

Cominsky, L

2004-03-23T23:59:59.000Z

266

Unidentified Gamma-Ray Sources and Microquasars  

E-Print Network (OSTI)

Some phenomenological properties of the unidentified EGRET detections suggest that there are two distinct groups of galactic gamma-ray sources that might be associated with compact objects endowed with relativistic jets. We discuss different models for gamma-ray production in both microquasars with low- and high-mass stellar companions. We conclude that the parent population of low-latitude and halo variable sources might be formed by yet undetected microquasars and microblazars.

G. E. Romero; I. A Grenier; M. M. Kaufman Bernado; I. F. Mirabel; D. F. Torres

2004-02-12T23:59:59.000Z

267

Theoretical Models of Gamma-Ray Bursts  

E-Print Network (OSTI)

Models of gamma ray bursts are reviewed in the light of recent observations of afterglows which point towards a cosmological origin. The physics of fireball shock models is discussed, with attention to the type of light histories and spectra during the gamma-ray phase. The evolution of the remnants and their afterglows is considered, as well as their implications for our current understanding of the mechanisms giving rise to the bursts.

P. Meszaros

1997-11-28T23:59:59.000Z

268

Radiodetection of Cosmic Ray Extensive Air Showers  

E-Print Network (OSTI)

We present the characteristics and performance of a demonstration experiment devoted to the observation of ultra high- energy cosmic ray extensive air showers using a radiodetection technique. In a first step, one antenna narrowed band filtered acting as trigger, with a 4 $\\sigma$ threshold above sky background-level, was used to tag any radio transient in coincidence on the antenna array. Recently, the addition of 4 particle detectors has allowed us to observe cosmic ray events in coincidence with antennas.

D. Ardouin; A. Belletoile; D. Charrier; R. Dallier; L. Denis; P. Eschstruth; T. Gousset; F. Haddad; J. Lamblin; P. Lautridou; A. Lecacheux; D. Monnier-Ragaiggne; A. Rahmani; O. Ravel; the Codalema Collaboration

2004-12-09T23:59:59.000Z

269

Hard x-ray or gamma ray laser by a dense electron beam  

SciTech Connect

A dense electron beam propagating through a laser undulator can radiate a coherent x-ray or gamma ray. This lasing scheme is studied with the Landau damping theory. The analysis suggests that, with currently available physical parameters, coherent gamma rays of up to 50 keV can be generated. The electron quantum diffraction suppresses the free electron laser action, which limits the maximum radiation.

Son, S. [18 Caleb Lane, Princeton, New Jersey 08540 (United States); Joon Moon, Sung [8 Benjamin Rush Ln., Princeton, New Jersey 08540 (United States)

2012-06-15T23:59:59.000Z

270

Argonne CNM: X-Ray Microscopy Capabilities  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Microscopy Facilities X-Ray Microscopy Facilities The Hard X-Ray Nanoprobe (HXN) facility provides scanning fluorescence, scanning diffraction, and full-field transmission and tomographic imaging capabilities with a spatial resolution of 30 nm over a spectral range of 6-12 keV. Modes of Operation Full-Field Transmission Imaging and Nanotomography X-ray transmission imaging uses both the absorption and phase shift of the X-ray beam by the sample as contrast mechanisms. Absorption contrast is used to map the sample density. Elemental constituents can be located by using differential edge contrast in this mode. Phase contrast can be highly sensitive to edges and interfaces even when the X-ray absorption is weak. These contrast mechanisms are exploited to image samples rapidly in full-field transmission mode under various environmental conditions, or combined with nanotomography methods to study the three-dimensional structure of complex and amorphous nanomaterials with the HXN.

271

Lensless X-Ray Imaging in Reflection  

NLE Websites -- All DOE Office Websites (Extended Search)

Lensless X-Ray Imaging in Reflection Print Lensless X-Ray Imaging in Reflection Print The advent of x-ray free-electron laser (XFEL) light sources has led to an outburst of research activities in the field of lensless imaging. XFELs combine the advantages of sychrotron light sources (high brightness and x-ray wavelengths relevant to atomic and molecular phenomena) with the advantages of visible-light lasers (highly coherent beams). All of these characteristics are important for coherent x-ray diffraction imaging-lensless imaging techniques that are proving to be integral to single-shot, high-resolution imaging of both complex materials and biological samples. Existing techniques are typically designed for transmission geometry, however, and use isolated objects, requiring special sample fabrication and restricting the type of samples under investigation. Recently, researchers from the ALS and the University of Oregon have shown at ALS Beamline 12.0.2 that it is possible to form x-ray holograms in reflection geometry by using the light scattered from a sample, opening the door to lensless imaging of a wealth of new material samples.

272

Lensless X-Ray Imaging in Reflection  

NLE Websites -- All DOE Office Websites (Extended Search)

Lensless X-Ray Imaging in Reflection Print Lensless X-Ray Imaging in Reflection Print The advent of x-ray free-electron laser (XFEL) light sources has led to an outburst of research activities in the field of lensless imaging. XFELs combine the advantages of sychrotron light sources (high brightness and x-ray wavelengths relevant to atomic and molecular phenomena) with the advantages of visible-light lasers (highly coherent beams). All of these characteristics are important for coherent x-ray diffraction imaging-lensless imaging techniques that are proving to be integral to single-shot, high-resolution imaging of both complex materials and biological samples. Existing techniques are typically designed for transmission geometry, however, and use isolated objects, requiring special sample fabrication and restricting the type of samples under investigation. Recently, researchers from the ALS and the University of Oregon have shown at ALS Beamline 12.0.2 that it is possible to form x-ray holograms in reflection geometry by using the light scattered from a sample, opening the door to lensless imaging of a wealth of new material samples.

273

Lensless X-Ray Imaging in Reflection  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Imaging in Reflection Print X-Ray Imaging in Reflection Print The advent of x-ray free-electron laser (XFEL) light sources has led to an outburst of research activities in the field of lensless imaging. XFELs combine the advantages of sychrotron light sources (high brightness and x-ray wavelengths relevant to atomic and molecular phenomena) with the advantages of visible-light lasers (highly coherent beams). All of these characteristics are important for coherent x-ray diffraction imaging-lensless imaging techniques that are proving to be integral to single-shot, high-resolution imaging of both complex materials and biological samples. Existing techniques are typically designed for transmission geometry, however, and use isolated objects, requiring special sample fabrication and restricting the type of samples under investigation. Recently, researchers from the ALS and the University of Oregon have shown at ALS Beamline 12.0.2 that it is possible to form x-ray holograms in reflection geometry by using the light scattered from a sample, opening the door to lensless imaging of a wealth of new material samples.

274

Lensless X-Ray Imaging in Reflection  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Imaging in Reflection Print X-Ray Imaging in Reflection Print The advent of x-ray free-electron laser (XFEL) light sources has led to an outburst of research activities in the field of lensless imaging. XFELs combine the advantages of sychrotron light sources (high brightness and x-ray wavelengths relevant to atomic and molecular phenomena) with the advantages of visible-light lasers (highly coherent beams). All of these characteristics are important for coherent x-ray diffraction imaging-lensless imaging techniques that are proving to be integral to single-shot, high-resolution imaging of both complex materials and biological samples. Existing techniques are typically designed for transmission geometry, however, and use isolated objects, requiring special sample fabrication and restricting the type of samples under investigation. Recently, researchers from the ALS and the University of Oregon have shown at ALS Beamline 12.0.2 that it is possible to form x-ray holograms in reflection geometry by using the light scattered from a sample, opening the door to lensless imaging of a wealth of new material samples.

275

Delayed Nickel Decay in Gamma Ray Bursts  

E-Print Network (OSTI)

Recently observed emission lines in the X-ray afterglow of gamma ray bursts suggest that iron group elements are either produced in the gamma ray burst, or are present nearby. If this material is the product of a thermonuclear burn, then such material would be expected to be rich in Nickel-56. If the nickel remains partially ionized, this prevents the electron capture reaction normally associated with the decay of Nickel-56, dramatically increasing the decay timescale. Here we examine the consequences of rapid ejection of a fraction of a solar mass of iron group material from the center of a collapsar/hypernova. The exact rate of decay then depends on the details of the ionization and therefore the ejection process. Future observations of iron, nickel and cobalt lines can be used to diagnose the origin of these elements and to better understand the astrophysical site of gamma ray bursts. In this model, the X-ray lines of these iron-group elements could be detected in suspected hypernovae that did not produce an observable gamma ray burst due to beaming.

G. C. McLaughlin; R. A. M. J. Wijers

2002-05-19T23:59:59.000Z

276

Compton backscattered collimated x-ray source  

SciTech Connect

A high-intensity, inexpensive and collimated x-ray source for applications such as x-ray lithography is disclosed. An intense pulse from a high power laser, stored in a high-finesse resonator, repetitively collides nearly head-on with and Compton backscatters off a bunched electron beam, having relatively low energy and circulating in a compact storage ring. Both the laser and the electron beams are tightly focused and matched at the interaction region inside the optical resonator. The laser-electron interaction not only gives rise to x-rays at the desired wavelength, but also cools and stabilizes the electrons against intrabeam scattering and Coulomb repulsion with each other in the storage ring. This cooling provides a compact, intense bunch of electrons suitable for many applications. In particular, a sufficient amount of x-rays can be generated by this device to make it an excellent and flexible Compton backscattered x-ray (CBX) source for high throughput x-ray lithography and many other applications.

Ruth, Ronald D. (Woodside, CA); Huang, Zhirong (Stanford, CA)

1998-01-01T23:59:59.000Z

277

Compton backscattered collmated X-ray source  

SciTech Connect

A high-intensity, inexpensive and collimated x-ray source for applications such as x-ray lithography is disclosed. An intense pulse from a high power laser, stored in a high-finesse resonator, repetitively collides nearly head-on with and Compton backscatters off a bunched electron beam, having relatively low energy and circulating in a compact storage ring. Both the laser and the electron beams are tightly focused and matched at the interaction region inside the optical resonator. The laser-electron interaction not only gives rise to x-rays at the desired wavelength, but also cools and stabilizes the electrons against intrabeam scattering and Coulomb repulsion with each other in the storage ring. This cooling provides a compact, intense bunch of electrons suitable for many applications. In particular, a sufficient amount of x-rays can be generated by this device to make it an excellent and flexible Compton backscattered x-ray (CBX) source for high throughput x-ray lithography and many other applications.

Ruth, Ronald D. (Woodside, CA); Huang, Zhirong (Stanford, CA)

2000-01-01T23:59:59.000Z

278

Edge-ray principle of nonimaging optics  

SciTech Connect

The edge-ray principle of nonimaging optics states that nonimaging devices can be designed by the mapping of edge rays from the source to the edge of the target. However, in most nonimaging reflectors, including the compound parabolic concentrator (CPC), at least part of the radiation undergoes multiple reflections, some rays even appear to be reflected infinitely many times, and closer examination reveals that some edge rays of the source are not mapped onto the edge of the target even though the CPC is indeed in two dimensions. Using a topological approach, the authors refine the formulation of the edge-ray principle to ensure its validity for all configurations. They present two different versions of the general principle. The first involves the boundaries of the different zones corresponding to a different number of reflections. The second version is stated in terms of only a single reflection, but it involves the addition of an auxiliary region of phase space. The authors discuss the use of the edge-ray principle as a design procedure for nonimaging devices. The CPC is used to illustrate all steps of the argument.

Ries, H. [Univ. of Munich (Germany); Rabl, A. [Univ. of Colorado, Boulder, CO (United States)

1994-10-01T23:59:59.000Z

279

Transient x-ray diffraction and its application to materials science and x-ray optics  

SciTech Connect

Time resolved x-ray diffraction and scattering have been applied to the measurement of a wide variety of physical phenomena from chemical reactions to shock wave physics. Interest in this method has heightened in recent years with the advent of versatile, high power, pulsed x-ray sources utilizing laser plasmas, electron beams and other methods. In this article, we will describe some of the fundamentals involved in time resolved x-ray diffraction, review some of the history of its development, and describe some recent progress in the field. In this article we will emphasize the use of laser-plasmas as the x-ray source for transient diffraction.

Hauer, A.A.; Kopp, R.; Cobble, J.; Kyrala, G.; Springer, R. [and others

1997-12-01T23:59:59.000Z

280

Lag-luminosity relation in gamma-ray burst X-ray flares  

Science Conference Proceedings (OSTI)

In strict analogy to prompt pulses, X-ray flares observed by Swift-XRT in long Gamma-Ray Bursts define a lag-luminosity relation: L{sub p,iso}{sup 0.3-10} k{sup eV} {infinity}t{sub lag}{sup -0.95{+-}0.23}. The lag-luminosity is proven to be a fundamental law extending {approx}5 decades in time and {approx}5 in energy. This is direct evidence that GRB X-ray flares and prompt gamma-ray pulses are produced by the same mechanism.

Margutti, R.

2010-10-15T23:59:59.000Z

Note: This page contains sample records for the topic "keynote ray mabus" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Are gamma-ray bursts the sources of ultra-high energy cosmic rays?  

E-Print Network (OSTI)

We reconsider the possibility that gamma-ray bursts (GRBs) are the sources of the ultra-high energy cosmic rays (UHECRs) within the internal shock model, assuming a pure proton composition of the UHECRs. For the first time, we combine the information from gamma-rays, cosmic rays, prompt neutrinos, and cosmogenic neutrinos quantitatively in a joint cosmic ray production and propagation model, and we show that the information on the cosmic energy budget can be obtained as a consequence. In addition to the neutron model, we consider alternative scenarios for the cosmic ray escape from the GRBs, i.e., that cosmic rays can leak from the sources. We find that the dip model, which describes the ankle in UHECR observations by the pair production dip, is strongly disfavored in combination with the internal shock model because a) unrealistically high baryonic loadings (energy in protons versus energy in electrons/gamma-rays) are needed for the individual GRBs and b) the prompt neutrino flux easily overshoots the corresponding neutrino bound. On the other hand, GRBs may account for the UHECRs in the ankle transition model if cosmic rays leak out from the source at the highest energies. In that case, we demonstrate that future neutrino observations can efficiently test most of the parameter space -- unless the baryonic loading is much larger than previously anticipated.

Philipp Baerwald; Mauricio Bustamante; Walter Winter

2014-01-08T23:59:59.000Z

282

X-Ray Data from the X-Ray Data Booklet Online  

DOE Data Explorer (OSTI)

The original X-Ray Data Booklet, published in 1985, became a classic reference source. The online version has been significantly revised and updated to reflect today's science. Hundreds of pages of authoritative data provide the x-ray properties of elements, information on synchrotron radiation, scattering processes, optics and detectors, and other related calculations, formulas, and data tables.

Thompson, Albert C.; Attwood, David T.; Gullikson, Eric M.; Howells, Malcolm R.; Kortright, Jeffrey B.; Robinson, Arthur L.; Underwood, James H.; Kim, Kwang-Je; Kirz, Janos; Lindau, Ingolf; Pianetta, Piero; Winick, Herman; Williams, Gwyn P.; Scofield, James H.

283

High spatial resolution X-ray and gamma ray imaging system using diffraction crystals  

DOE Patents (OSTI)

A method and a device for high spatial resolution imaging of a plurality of sources of x-ray and gamma-ray radiation are provided. The device comprises a plurality of arrays, with each array comprising a plurality of elements comprising a first collimator, a diffracting crystal, a second collimator, and a detector.

Smither, Robert K. (Hinsdale, IL)

2011-05-17T23:59:59.000Z

284

COSMIC-RAY AND X-RAY HEATING OF INTERSTELLAR CLOUDS AND PROTOPLANETARY DISKS  

SciTech Connect

Cosmic-ray and X-ray heating are derived from the electron energy-loss calculations of Dalgarno, Yan, and Liu for hydrogen-helium gas mixtures. These authors treated the heating from elastic scattering and collisional de-excitation of rotationally excited hydrogen molecules. Here we consider the heating that can arise from all ionization and excitation processes, with particular emphasis on the reactions of cosmic-ray and X-ray generated ions with the heavy neutral species, which we refer to as chemical heating. In molecular regions, chemical heating dominates and can account for 50% of the energy expended in the creation of an ion pair. The heating per ion pair ranges in the limit of negligible electron fraction from {approx}4.3 eV for diffuse atomic gas to {approx}13 eV for the moderately dense regions of molecular clouds and to {approx}18 eV for the very dense regions of protoplanetary disks. An important general conclusion of this study is that cosmic-ray and X-ray heating depends on the physical properties of the medium, i.e., on the molecular and electron fractions, the total density of hydrogen nuclei, and, to a lesser extent, on the temperature. It is also noted that chemical heating, the dominant process for cosmic-ray and X-ray heating, plays a role in UV irradiated molecular gas.

Glassgold, Alfred E. [Astronomy Department, University of California, Berkeley, CA 94720-3411 (United States); Galli, Daniele [INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125 (Italy); Padovani, Marco, E-mail: aglassgold@berkeley.edu, E-mail: galli@arcetri.astro.it, E-mail: marco.padovani@lra.ens.fr [Laboratoire de Radioastronomie Millimetrique, UMR 8112 du CNRS, Ecole Normale Superieure et Observatoire de Paris, 24 rue Lhomond, F-75231 Paris Cedex 05 (France)

2012-09-10T23:59:59.000Z

285

Radiographic X-Ray Pulse Jitter  

Science Conference Proceedings (OSTI)

The Dual Beam Radiographic Facility consists of two identical radiographic sources. Major components of the machines are: Marx generator, water-filled pulse-forming line (PFL), water-filled coaxial transmission line, three-cell inductive voltage adder, and rod-pinch diode. The diode pulse has the following electrical specifications: 2.25-MV, 60-kA, 60-ns. Each source has the following x-ray parameters: 1-mm-diameter spot size, 4-rad at 1 m, 50-ns full width half max. The x-ray pulse is measured with PIN diode detectors. The sources were developed to produce high resolution images on single-shot, high-value experiments. For this application it is desirable to maintain a high level of reproducibility in source output. X-ray pulse jitter is a key metric for analysis of reproducibility. We will give measurements of x-ray jitter for each machine. It is expected that x-ray pulse jitter is predominantly due to PFL switch jitter, and therefore a correlation of the two will be discussed.

Mitton, C. V., Good, D. E., Henderson, D. J., Hogge, K. W.

2011-01-15T23:59:59.000Z

286

Cosmic Ray Interactions in Shielding Materials  

SciTech Connect

This document provides a detailed study of materials used to shield against the hadronic particles from cosmic ray showers at Earths surface. This work was motivated by the need for a shield that minimizes activation of the enriched germanium during transport for the MAJORANA collaboration. The materials suitable for cosmic-ray shield design are materials such as lead and iron that will stop the primary protons, and materials like polyethylene, borated polyethylene, concrete and water that will stop the induced neutrons. The interaction of the different cosmic-ray components at ground level (protons, neutrons, muons) with their wide energy range (from kilo-electron volts to giga-electron volts) is a complex calculation. Monte Carlo calculations have proven to be a suitable tool for the simulation of nucleon transport, including hadron interactions and radioactive isotope production. The industry standard Monte Carlo simulation tool, Geant4, was used for this study. The result of this study is the assertion that activation at Earths surface is a result of the neutronic and protonic components of the cosmic-ray shower. The best material to shield against these cosmic-ray components is iron, which has the best combination of primary shielding and minimal secondary neutron production.

Aguayo Navarrete, Estanislao; Kouzes, Richard T.; Ankney, Austin S.; Orrell, John L.; Berguson, Timothy J.; Troy, Meredith D.

2011-09-08T23:59:59.000Z

287

30TH INTERNATIONAL COSMIC RAY CONFERENCE Search for Gamma Ray Bursts using the single particle technique at the Pierre Auger  

E-Print Network (OSTI)

30TH INTERNATIONAL COSMIC RAY CONFERENCE Search for Gamma Ray Bursts using the single particle by satellites. Introduction Since their discovery at the end of the 60s[1], Gamma Ray Bursts (GRB) have been of high in- terest to astrophysics. A GRB is characterised by a sudden emission of gamma rays during

Hörandel, Jörg R.

288

GreenRay Inc | Open Energy Information  

Open Energy Info (EERE)

GreenRay Inc GreenRay Inc Jump to: navigation, search Name GreenRay Inc Place Westford, Massachusetts Zip 1886 Product US-based manufacturer of residential AC PV module system that integrates an inverter; still in development stage. Coordinates 44.614908°, -73.015053° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":44.614908,"lon":-73.015053,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

289

RayTracker Inc | Open Energy Information  

Open Energy Info (EERE)

RayTracker Inc RayTracker Inc Jump to: navigation, search Name RayTracker Inc. Place Pasadena, California Zip 91103 Sector Solar Product California-based maker of single-axis solar tracker systems. Coordinates 29.690847°, -95.196308° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":29.690847,"lon":-95.196308,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

290

Muon Acceleration in Cosmic-ray Sources  

E-Print Network (OSTI)

Many models of ultra-high energy cosmic-ray production involve acceleration in linear accelerators located in Gamma-Ray Bursts magnetars, or other sources. These source models require very high accelerating gradients, $10^{13}$ keV/cm, with the minimum gradient set by the length of the source. At gradients above 1.6 keV/cm, muons produced by hadronic interactions undergo significant acceleration before they decay. This acceleration hardens the neutrino energy spectrum and greatly increases the high-energy neutrino flux. We rule out many models of linear acceleration, setting strong constraints on plasma wakefield accelerators and on models for sources like Gamma Ray Bursts and magnetars.

Spencer R. Klein; Rune Mikkelsen; Julia K. Becker Tjus

2012-08-09T23:59:59.000Z

291

CAN ULTRAHIGH-ENERGY COSMIC RAYS COME FROM GAMMA-RAY BURSTS? COSMIC RAYS BELOW THE ANKLE AND GALACTIC GAMMA-RAY BURSTS  

SciTech Connect

The maximum cosmic-ray energy achievable by acceleration by a relativistic blast wave is derived. It is shown that forward shocks from long gamma-ray bursts (GRBs) in the interstellar medium accelerate protons to large enough energies, and have a sufficient energy budget, to produce the Galactic cosmic-ray component just below the ankle at 4 x 10{sup 18} eV, as per an earlier suggestion. It is further argued that, were extragalactic long GRBs responsible for the component above the ankle as well, the occasional Galactic GRB within the solar circle would contribute more than the observational limits on the outward flux from the solar circle, unless an avoidance scenario, such as intermittency and/or beaming, allows the present-day local flux to be less than 10{sup -3} of the average. Difficulties with these avoidance scenarios are noted.

Eichler, David [Physics Department, Ben-Gurion University, Be'er-Sheva 84105 (Israel); Pohl, Martin [Institut fuer Physik und Astronomie, Universitaet Potsdam, 14476 Potsdam-Golm (Germany)

2011-09-10T23:59:59.000Z

292

Fermi Observations of Gamma-ray Bursts  

SciTech Connect

The gamma-ray emission mechanism of Gamma-ray bursts (GRBs) are still unknown. Fermi Gamma-ray Space Telescope successfully detected high-energy (> 100 MeV) emission from 17 GRBs since its launch. Fermi revealed the distinct temporal behaviors and extra spectral component from high-energy emission. These new observational results are driving many theoretical implications, such as leptonic, hadronic and afterglow origin. The highest energy photon detected by Fermi gives a constraint on the bulk Lorentz factor of the ultra-relativistic jets of GRBs. The impact of the Fermi GRB observations extends not only to the GRB-related issues but also to the outside GRB physics, such as quantum gravity and model of the extra galactic background light.

Ohno, Masanori [Institute of Space and Astronautical Science, JAXA, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan)

2010-10-15T23:59:59.000Z

293

Frontiers in X-Ray Science  

Science Conference Proceedings (OSTI)

The year 2010 marked the fiftieth anniversary of the optical laser and the first anniversary of the world's first hard x-ray free-electron laser, the Linac Coherent Light Source (LCLS) at SLAC. This exciting, new accelerator-based source of x-rays provides peak brilliances roughly a billion times greater than currently available from synchrotron sources such as the Advanced Photon Source at Argonne, and thus explores a qualitatively different parameter space. This talk will describe the first experiments at the LCLS aimed at understanding the nature of high intensity x-ray interactions, related applications in ultrafast imaging on the atomic scale and sketch nascent plans for the extension of both linac and storage-ring based photon sources.

Linda Young

2011-02-23T23:59:59.000Z

294

COMPTEL Observations of Gamma-ray Bursts  

E-Print Network (OSTI)

INTRODUCTION The origin of cosmic g-ray bursts is as mysterious today as it was when they were discovered more than 25 years ago. Despite a wealth of new observational data obtained with the BATSE instrument on board the Compton Gamma Ray Observatory, many of the fundamental questions remain unanswered. For instance, although BATSE has provided a tremendous statistical advantage (allowing the most accurate measurement of the spatial isotropy and inhomogeneity of burst sources ), its limited angular resolution and spectral range have given us an incomplete picture of the small-scale angular source distribution and high energy emission properties. 2,3 Furthermore, the limited angular resolution has also made it difficult to search for burst counterparts at other wavelengths. The COMPTEL instrument on board Compton measures the locations and spectra (0.75-30 MeV) of several strong g-ray bursts per year which occur within the ~1 sr fieldof -view of the main ("telescope") instrument.

Kippen Ryan Connors; R. M. Kippen; B J. Ryan; B A. Connors; B M. Mcconnell; V. Schnfelder; C J. Greiner; C M. Varendorff; W. Collmar; C W. Hermsen; D L. Kuiper; D C. Winkler; L. O. Hanlon E; K. S. Oflaherty E

1995-01-01T23:59:59.000Z

295

HETEROGENEITY IN SHORT GAMMA-RAY BURSTS  

SciTech Connect

We analyze the Swift/BAT sample of short gamma-ray bursts, using an objective Bayesian Block procedure to extract temporal descriptors of the bursts' initial pulse complexes (IPCs). The sample is comprised of 12 and 41 bursts with and without extended emission (EE) components, respectively. IPCs of non-EE bursts are dominated by single pulse structures, while EE bursts tend to have two or more pulse structures. The medians of characteristic timescales-durations, pulse structure widths, and peak intervals-for EE bursts are factors of {approx}2-3 longer than for non-EE bursts. A trend previously reported by Hakkila and colleagues unifying long and short bursts-the anti-correlation of pulse intensity and width-continues in the two short burst groups, with non-EE bursts extending to more intense, narrower pulses. In addition, we find that preceding and succeeding pulse intensities are anti-correlated with pulse interval. We also examine the short burst X-ray afterglows as observed by the Swift/X-Ray Telescope (XRT). The median flux of the initial XRT detections for EE bursts ({approx}6x10{sup -10} erg cm{sup -2} s{sup -1}) is {approx}>20x brighter than for non-EE bursts, and the median X-ray afterglow duration for EE bursts ({approx}60,000 s) is {approx}30x longer than for non-EE bursts. The tendency for EE bursts toward longer prompt-emission timescales and higher initial X-ray afterglow fluxes implies larger energy injections powering the afterglows. The longer-lasting X-ray afterglows of EE bursts may suggest that a significant fraction explode into denser environments than non-EE bursts, or that the sometimes-dominant EE component efficiently powers the afterglow. Combined, these results favor different progenitors for EE and non-EE short bursts.

Norris, Jay P. [Physics and Astronomy Department, University of Denver, Denver, CO 80208 (United States); Gehrels, Neil [Astroparticle Physics Laboratory, NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Scargle, Jeffrey D. [Space Science and Astrobiology Division, NASA/Ames Research Center, Moffett Field, CA 94035-1000 (United States)

2011-07-01T23:59:59.000Z

296

Radiobiological studies using gamma and x rays.  

Science Conference Proceedings (OSTI)

There are approximately 500 self-shielded research irradiators used in various facilities throughout the U.S. These facilities use radioactive sources containing either 137Cs or 60Co for a variety of biological investigations. A report from the National Academy of Sciences[1] described the issues with security of particular radiation sources and the desire for their replacement. The participants in this effort prepared two peer-reviewed publications to document the results of radiobiological studies performed using photons from 320-kV x rays and 137Cs on cell cultures and mice. The effectiveness of X rays was shown to vary with cell type.

Potter, Charles Augustus; Longley, Susan W.; Scott, Bobby R. [Lovelace Respiratory Research Institute, Albuquerque, NM; Lin, Yong [Lovelace Respiratory Research Institute, Albuquerque, NM; Wilder, Julie [Lovelace Respiratory Research Institute, Albuquerque, NM; Hutt, Julie A. [Lovelace Respiratory Research Institute, Albuquerque, NM; Padilla, Mabel T. [Lovelace Respiratory Research Institute, Albuquerque, NM; Gott, Katherine M. [Lovelace Respiratory Research Institute, Albuquerque, NM

2013-02-01T23:59:59.000Z

297

X-ray Science Division: Groups  

NLE Websites -- All DOE Office Websites (Extended Search)

Division: Groups Division: Groups Atomic, Molecular and Optical Physics (AMO) Primary Contact: Stephen Southworth Work focuses on understanding how strong optical and x-ray fields interact with matter, with an emphasis on photonic control of electronic, atomic and molecular motion. Chemical and Materials Science (CMS) Primary Contact: Randy Winans Research Disciplines: Chemistry, Materials Science Detectors (DET) Primary Contact: Antonino Miceli GMCA Structural Biology Facility (MX) Primary Contact: Robert Fischetti Research Disciplines: Biology, Life Sciences Imaging (IMG) Primary Contact: Francesco DeCarlo Research Disciplines: Materials Science, Biology, Physics, Life Sciences Inelastic X-ray & Nuclear Resonant Scattering (IXN) Primary Contact: Thomas Gog Research Disciplines: Condensed Matter Physics, Geophysics, Materials

298

Gamma-Ray Bursts: Jets and Energetics  

E-Print Network (OSTI)

The relativistic outflows from gamma-ray bursts are now thought to be narrowly collimated into jets. After correcting for this jet geometry there is a remarkable constancy of both the energy radiated by the burst and the kinetic energy carried by the outflow. Gamma-ray bursts are still the most luminous explosions in the Universe, but they release energies that are comparable to supernovae. The diversity of cosmic explosions appears to be governed by the fraction of energy that is coupled to ultra-relativistic ejecta.

D. A. Frail

2003-11-12T23:59:59.000Z

299

A Shotgun Model for Gamma Ray Bursts  

E-Print Network (OSTI)

We propose that gamma ray bursts (GRBs) are produced by a shower of heavy blobs running into circumstellar material at highly relativistic speeds. The gamma ray emission is produced in the shocks these bullets drive into the surrounding medium. The short term variability seen in GRBs is set by the slowing-down time of the bullets while the overall duration of the burst is set by the lifetime of the central engine. A requirement of this model is that the ambient medium be dense, consistent with a strong stellar wind. The efficiency of the burst can be relatively high.

S. Heinz; M. C. Begelman

1999-08-03T23:59:59.000Z

300

Redshift indicators for gamma-ray bursts  

E-Print Network (OSTI)

The measure of the distances and luminosities of gamma-ray bursts (GRBs) led to the discovery that many GRB properties are strongly correlated with their intrinsic luminosity, leading to the construction of reliable luminosity indicators. These GRB luminosity indicators have quickly found applications, like the construction of 'pseudo-redshifts', or the measure of luminosity distances, which can be computed independently of the measure of the redshift. In this contribution I discuss various issues connected with the construction of luminosity-redshift indicators for gamma-ray bursts.

J-L. Atteia

2005-05-04T23:59:59.000Z

Note: This page contains sample records for the topic "keynote ray mabus" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

A supersymmetric model of gamma ray bursts  

E-Print Network (OSTI)

We propose a model for gamma ray bursts in which a star subject to a high level of fermion degeneracy undergoes a phase transition to a supersymmetric state. The burst is initiated by the transition of fermion pairs to sfermion pairs which, uninhibited by the Pauli exclusion principle, can drop to the ground state of minimum momentum through photon emission. The jet structure is attributed to the Bose statistics of sfermions whereby subsequent sfermion pairs are preferentially emitted into the same state (sfermion amplification by stimulated emission). Bremsstrahlung gamma rays tend to preserve the directional information of the sfermion momenta and are themselves enhanced by stimulated emission.

L. Clavelli; G. Karatheodoris

2004-03-22T23:59:59.000Z

302

Status of the Milagro $\\gamma$ Ray Observatory  

E-Print Network (OSTI)

The Milagro Gamma Ray Observatory is the world's first large-area water Cherenkov detector capable of continuously monitoring the sky at TeV energies. Located in northern New Mexico, Milagro will perform an all sky survey of the Northern Hemisphere at energies between ~250 GeV and 50 TeV. With a high duty cycle, large detector area (~5000 square meters), and a wide field-of-view (~1 sr), Milagro is uniquely capable of searching for transient and DC sources of high-energy gamma-ray emission. Milagro has been operating since February, 1999. The current status of the Milagro Observatory and initial results will be discussed.

Atkins, R; Berley, D; Chen, M L; Coyne, D G; Delay, R S; Dingus, B L; Dorfan, D E; Ellsworth, R W; Evans, D; Falcone, A D; Fleysher, L; Fleysher, R; Gisler, G; Goodman, J A; Haines, T J; Hoffman, C M; Hugenberger, S; Kelley, L A; Leonor, I; Macri, J R; McConnell, M; McCullough, J F; McEnery, J E; Miller, R S; Mincer, A I; Morales, M F; Nmethy, P; Ryan, J M; Schneider, M; Shen, B; Shoup, A L; Sinnis, G; Smith, A J; Sullivan, G W; Thompson, T N; Tmer, T O; Wang, K; Wascko, M O; Westerhoff, S; Williams, D A; Yang, T; Yodh, G B

2001-01-01T23:59:59.000Z

303

ARPA-E 2011 Keynote: Secretary Steven Chu | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Pledge? Conversation on the Future of the Wind Industry Science Lecture: Talking the Higgs Boson with Dr. Joseph Incandela Bill Gates and Deputy Secretary Poneman Discuss the...

304

ARPA-E 2011 Keynote: Dr. Arun Majumdar | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Pledge? Conversation on the Future of the Wind Industry Science Lecture: Talking the Higgs Boson with Dr. Joseph Incandela Bill Gates and Deputy Secretary Poneman Discuss the...

305

Challenges in enabling social application at scale: cloudDB'12 invited-keynote talk abstract  

Science Conference Proceedings (OSTI)

Internet users spend billions of minutes per month on social networking sites like Facebook, LinkedIn and Twitter. Not only do they create tons of data everyday in the form of posts, tweets and photos, the connections between users have given rise to ... Keywords: differential privacy, enmeshed queries, feed following, social coordination, social recommendations

Ashwin Machanavajjhala

2012-10-01T23:59:59.000Z

306

ARPA-E 2011 Keynote: Dr. Arun Majumdar | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Energy 101: Solar PV Sec. Chu Online Town Hall Energy 101: Cool Roofs Energy 101: Geothermal Heat Pumps Why Cool Roofs? Chu at COP-16: Building a Sustainable Energy Future...

307

ARPA-E 2011 Keynote: Secretary Steven Chu | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Energy 101: Solar PV Sec. Chu Online Town Hall Energy 101: Cool Roofs Energy 101: Geothermal Heat Pumps Why Cool Roofs? Chu at COP-16: Building a Sustainable Energy Future...

308

Keynote Presentation at ISFNT-9, Dalian, China, October 12, 2009 Mohamed Abdou  

E-Print Network (OSTI)

.ig.energy.gov/documents/CalendarYear2003/ig-0632.pdf CANDU Reactors: 27 kg from over 40 years, $30M/kg (current) Tritium Decays at 5.47% per year CANDU Supply w/o Fusion With ITER: 2016 1st Plasma, 4 yr. HH/DD Tritium decays at 5.47% per

California at Los Angeles, University of

309

ARPA-E 2011 Keynote: Secretary Steven Chu | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Recovery Act Transforming the American Economy Through Innovation Linac Coherent Light Source Overview Matt Rogers on AES Energy Storage Energy 101: Concentrating Solar Power...

310

Frameworks and data initiatives for smart grid and other cyber-physical systems (invited keynote)  

Science Conference Proceedings (OSTI)

I describe the NIST smart grid framework and its applicability as a model for organizational efforts to advance cyber-physical systems, and provide an overview of smart grid data initiatives. Keywords: cybersecurity, data analytics, data initiatives, frameworks, green button, interoperability, smart grid, testing and certification

David A. Wollman

2013-06-01T23:59:59.000Z

311

ARPA-E 2011 Keynote: Secretary Steven Chu | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

me talk about what we're facing. This is a recent history - inflation-adjusted history of oil prices from 1996 to 2011. Well, that goes to 2010 but that's the price today, roughly...

312

Keynote Address by NASA Administrator Charles F. Bolden Jr. American Astronomical Society Winter Meeting  

E-Print Network (OSTI)

was launched in December, our newest mission in the Explorer program. It will gather a treasure trove of new. By combining data from Chandra and other optical and infrared telescopes, the most distant galaxy cluster ever as distant stars and nebulae in our g

313

Beckman presents keynote address at ParCo2013 | Argonne National...  

NLE Websites -- All DOE Office Websites (Extended Search)

talk at the International Conference on Parallel Computing (ParCo2013) in Munich, Germany, September 10. Established in 1983, ParCo is one of the longest running international...

314

ARPA-E 2011 Keynote: Dr. Arun Majumdar | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

of any industrialized economy is the use of energy, and particularly energy to permit mobility: cars, trucks and planes. We at FedEx believe that the nation's dependence on...

315

ARPA-E 2011 Keynote: Secretary Steven Chu | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

these jet engines, and in that sense it can actually become much more efficient than the turbines of today. Looking at a number of other things - building efficiency through...

316

Ultra-high energy cosmic rays, cascade gamma-rays, and high-energy neutrinos from gamma-ray bursts  

E-Print Network (OSTI)

Gamma-ray bursts (GRBs) are sources of energetic, highly variable fluxes of gamma rays, which demonstrates that they are powerful particle accelerators. Besides relativistic electrons, GRBs should also accelerate high-energy hadrons, some of which could escape cooling to produce ultra-high energy cosmic rays (UHECRs). Acceleration of high-energy hadrons in GRB blast waves will be established if high-energy neutrinos produced through photopion interactions in the blast wave are detected from GRBs. Limitations on the energy in nonthermal hadrons and the number of expected neutrinos are imposed by the fluxes from pair-photon cascades initiated in the same processes that produce neutrinos. Only the most powerful bursts at fluence levels >~ 3e-4 erg/cm^2 offer a realistic prospect for detection of >> TeV neutrinos. Detection of high-energy neutrinos is likely if GRB blast waves have large baryon loads and Doppler factors <~ 200. Cascade gamma rays will accompany neutrino production and might already have been detected as anomalous emission components in the spectra of some GRBs. Prospects for detection of GRBs in the Milky Way are also considered.

Charles D. Dermer; Armen Atoyan

2006-06-26T23:59:59.000Z

317

The Soft-X-Ray Spectral Shape of X-Ray-Weak Seyferts  

E-Print Network (OSTI)

(I) We observed eight Seyfert~2s and two X--ray--weak Seyfert~1/QSOs with the ROSAT PSPC, and one Seyfert~2 with the ROSAT HRI. These targets were selected from the Extended 12\\um\\ Galaxy Sample. (II) Both Seyfert~1/QSOs vary by factors of 1.5---2. The photon indices steepen in the more luminous state, consistent with the variability being mainly due to the softest X--rays, which are confined to a size of less than a parsec. (III) Both the Seyfert~2s and Seyfert~1/QSOs are best fit with a photon index of $\\Gamma\\sim3$, which is steeper than the canonical value of $\\Gamma\\sim1.7$ measured for X--ray--strong Seyferts by ROSAT and at higher energies. Several physical explanations are suggested for the steeper slopes of X--ray--weak objects. (IV) We observed one Seyfert~2, NGC~5005, with the ROSAT HRI, finding about 13\\% of the soft X--rays to come from an extended component. This and other observations suggest that different components to the soft X--ray spectrum of some, if not all, X--ray--weak Seyferts may come from spatially distinct regions.

Brian Rush; Matthew A. Malkan

1995-07-27T23:59:59.000Z

318

The strongest cosmic magnets: Soft Gamma-ray Repeaters and Anomalous X-ray Pulsars  

E-Print Network (OSTI)

Two classes of X-ray pulsars, the Anomalous X-ray Pulsars and the Soft Gamma-ray Repeaters, have been recognized in the last decade as the most promising candidates for being magnetars: isolated neutron stars powered by magnetic energy. I review the observational properties of these objects, focussing on the most recent results, and their interpretation in the magnetar model. Alternative explanations, in particular those based on accretion from residual disks, are also considered. The possible relations between these sources and other classes of neutron stars and astrophysical objects are also discussed.

Mereghetti, Sandro

2008-01-01T23:59:59.000Z

319

The strongest cosmic magnets: Soft Gamma-ray Repeaters and Anomalous X-ray Pulsars  

E-Print Network (OSTI)

Two classes of X-ray pulsars, the Anomalous X-ray Pulsars and the Soft Gamma-ray Repeaters, have been recognized in the last decade as the most promising candidates for being magnetars: isolated neutron stars powered by magnetic energy. I review the observational properties of these objects, focussing on the most recent results, and their interpretation in the magnetar model. Alternative explanations, in particular those based on accretion from residual disks, are also considered. The possible relations between these sources and other classes of neutron stars and astrophysical objects are also discussed.

Sandro Mereghetti

2008-04-01T23:59:59.000Z

320

Gamma-ray bursts: a Centauro's cry?  

E-Print Network (OSTI)

A new candidate for the gamma-ray bursts central engine is proposed: if in some energetic cosmic event a macroscopic amount of bubbles of the disoriented chiral condensate can be formed, then their subsequent decays will produce a relativistic fireball without the baryon loading problem. The neutron star to strange star transition is considered as a candidate example of such cosmic event.

Z. K. Silagadze

2003-03-04T23:59:59.000Z

Note: This page contains sample records for the topic "keynote ray mabus" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Sharper Focusing of Hard X-rays  

NLE Websites -- All DOE Office Websites (Extended Search)

Sharper Focusing of Hard X-rays FROM: Physics News Update Number 773 #1, April 12, 2006, by Phil Schewe and Ben Stein Note: This text has been slightly modified from the original. Sharper focusing of hard x-rays has been achieved with a device developed at Argonne National Lab. Because of their high energy, x-rays are hard to focus: they can be reflected from a surface but only at a glancing angle (less than a tenth of a degree); they can be refracted but the index of refraction is very close to 1, so that making efficient lenses becomes a problem; and they can be diffracted, but the relatively thick, variable pitch grating required for focusing is tricky to achieve. The Argonne device is of the diffraction type, and it consists of a stack of alternating layers of metal and silicon, made by depositing progressively thicker layers. When the x-rays fall on such a structure, nearly edge-on, what they see is a grating (called a linear zone plate) consisting of a sort of bar-code pattern.

322

Multiple wavelength x-ray monochromators  

DOE Patents (OSTI)

An apparatus and method is provided for separating input x-ray radiation containing first and second x-ray wavelengths into spatially separate first and second output radiation which contain the first and second x-ray wavelengths, respectively. The apparatus includes a crystalline diffractor which includes a first set of parallel crystal planes, where each of the planes is spaced a predetermined second distance from one another. The crystalline diffractor also includes a second set of parallel crystal planes inclined at an angle with respect to the first set of crystal planes where each of the planes of the second set of parallel crystal planes is spaced a predetermined second distance from one another. In one embodiment, the crystalline diffractor is comprised of a single crystal. In a second embodiment, the crystalline diffractor is comprised of a stack of two crystals. In a third embodiment, the crystalline diffractor includes a single crystal that is bent for focussing the separate first and second output x-ray radiation wavelengths into separate focal points.

Steinmeyer, P.A.

1991-01-01T23:59:59.000Z

323

Multiple wavelength x-ray monochromators  

DOE Patents (OSTI)

An apparatus and method is provided for separating input x-ray radiation containing first and second x-ray wavelengths into spatially separate first and second output radiation which contain the first and second x-ray wavelengths, respectively. The apparatus includes a crystalline diffractor which includes a first set of parallel crystal planes, where each of the planes is spaced a predetermined second distance from one another. The crystalline diffractor also includes a second set of parallel crystal planes inclined at an angle with respect to the first set of crystal planes where each of the planes of the second set of parallel crystal planes is spaced a predetermined second distance from one another. In one embodiment, the crystalline diffractor is comprised of a single crystal. In a second embodiment, the crystalline diffractor is comprised of a stack of two crystals. In a third embodiment, the crystalline diffractor includes a single crystal that is bent for focussing the separate first and second output x-ray radiation wavelengths into separate focal points.

Steinmeyer, P.A.

1991-12-31T23:59:59.000Z

324

Bremsstrahlung gamma rays from light Dark Matter  

E-Print Network (OSTI)

We discuss the often-neglected role of bremsstrahlung processes on the interstellar gas in computing indirect signatures of Dark Matter (DM) annihilation in the Galaxy, particularly for light DM candidates in the phenomenologically interesting O(10) GeV mass range. Especially from directions close to the Galactic Plane, the expected gamma-ray spectrum is altered via two effects: directly, by the photons emitted in the bremsstrahlung process on the interstellar gas by energetic electrons which are among the DM annihilation byproducts; indirectly, by the modification of the same electron spectrum, due to the additional energy loss process in the diffusion-loss equation (e.g. the resulting inverse Compton emission is altered). We quantify the importance of the bremsstrahlung emission in the GeV energy range, showing that it is the dominant component of the gamma-ray spectrum for some cases. We also find that, in regions in which bremsstrahlung dominates energy losses, the related gamma-ray emission is only moderately sensitive to possible large variations in the gas density. Still, we stress that, for computing precise spectra in the (sub-)GeV range, it is important to obtain a reliable description of the inner Galaxy gas distribution as well as to compute self-consistently the gamma emission and the solution to the diffusion-loss equation. For example, these are crucial issues to quantify and interpret meaningfully gamma-ray map `residuals' in terms of (light) DM annihilations.

Marco Cirelli; Pasquale D. Serpico; Gabrijela Zaharijas

2013-07-26T23:59:59.000Z

325

Massively parallel X-ray scattering simulations  

Science Conference Proceedings (OSTI)

Although present X-ray scattering techniques can provide tremendous information on the nano-structural properties of materials that are valuable in the design and fabrication of energy-relevant nano-devices, a primary challenge remains in the analyses ...

Abhinav Sarje; Xiaoye S. Li; Slim Chourou; Elaine R. Chan; Alexander Hexemer

2012-11-01T23:59:59.000Z

326

Galactic Models of Gamma-Ray Bursts  

E-Print Network (OSTI)

We describe observational evidence and theoretical calculations which support the high velocity neutron star model of gamma-ray bursts. We estimate the energetic requirements in this model, and discuss possible energy sources. we also consider radiative processes involved in the bursts.

Donald Q. Lamb; Tomasz Bulik; Paolo S. Coppi

1995-08-20T23:59:59.000Z

327

The gamma-ray burst GB 920622  

E-Print Network (OSTI)

We have analyzed the Ulysses, BATSE, and COMPTEL spectral data from the \\gamma-ray burst of June 22, 1992 (GB 920622). COMPTEL data reveal a hard to soft evolution within the first pulse of the burst, while the mean hardness ratios of the three pulses are the same. Unlike the single instrument spectra, the composite spectrum of GB 920622 averaged over the total burst duration ranging from 20 keV up to 10 MeV cannot be fit by a single power law. Instead, the spectrum shows continuous curvature across the full energy range. COMPTEL imaging and BATSE/Ulysses triangulation constrain the source location of GB 920622 to a ring sector 1.1 arcmin wide and 2 degrees long. This area has been searched for quiescent X-ray sources using \\ros survey data collected about two years before the burst. After the optical identification of the X-ray sources in and near the GRB location we conclude that no quiescent X-ray counterpart candidate for GB 920622 has been found.

Greiner, J; Bade, N; Fishman, G J; Hanlon, L O; Hurley, K; Kippen, R M; Kouveliotou, C; Preece, R D; Ryan, J; Schnfelder, V; Williams, O R; Winkler, C M; Bor, M; Niel, M

1995-01-01T23:59:59.000Z

328

X-Ray and Neutron Diffraction  

Science Conference Proceedings (OSTI)

Oct 20, 2010 ... Advanced X-Ray Scattering Techniques for Multi-Length Scale ... ?-Ti using the 3DXRD station 34-ID-E at the Advanced Photon Source, Argonne National Laboratory. ... Research at APS 34-ID-E, partly funded by BES/DOE.

329

Neutrino Balls and Gamma-Ray Bursts  

E-Print Network (OSTI)

We propose a mechanism by which the neutrino emission from a supernova-type explosion can be converted into a gamma-ray burst of total energy $\\sim 10^{50}$ ergs. This occurs naturally if the explosion is situated inside a ball of trapped neutrinos, which in turn may lie at a galactic core. There are possible unique signatures of this scenario.

B. Holdom; R. A. Malaney

1993-06-17T23:59:59.000Z

330

Soft x-ray laser microscope  

Science Conference Proceedings (OSTI)

The program consisted of two phases (Phase I and Phase II). The goal of the Phase I (first year program) was to design and construct the Soft X-ray Laser Contact Microscope. Such microscope was constructed and adapted to PPL's 18.2nm soft X-ray Laser (SXL), which in turn was modified and prepared for microscopy experiments. Investigation of the photoresist response to 18.2nm laser radiation and transmissivity of 0.1m thick silicion-nitride (Si[sub 3]N[sub 4]) windows were important initial works. The goal of the first year of Phase II was to construct X-ray contact microscope in combination with existing optical phase microscope, already used by biologists. In the second year of Phase II study of dehydrated Horeseshoe Crab and Hela cancer cells were performed with COXRALM. Also during Phase II, the Imaging X-Ray Laser Microscope (IXRALM) was designed and constructed. This paper describes the development of each of the microscopes and their application for research.

Suckewer, P.I.

1990-10-01T23:59:59.000Z

331

A supersymmetric origin of gamma ray bursts  

E-Print Network (OSTI)

Bright bursts of gamma rays from outer space have been puzzling Astronomers for more than thirty years and there is still no conceptually complete model for the phenomenon within the standard model of particle physics. Is it time to consider a supersymmetric (SUSY) origin for these bursts to add to the astronomical indications of supersymmetry from dark matter?

L. Clavelli

2004-10-01T23:59:59.000Z

332

Small Angle X-Ray Scattering Detector  

DOE Patents (OSTI)

A detector for time-resolved small-angle x-ray scattering includes a nearly constant diameter, evacuated linear tube having an end plate detector with a first fluorescent screen and concentric rings of first fiber optic bundles for low angle scattering detection and an annular detector having a second fluorescent screen and second fiber optic bundles concentrically disposed about the tube for higher angle scattering detection. With the scattering source, i.e., the specimen under investigation, located outside of the evacuated tube on the tube's longitudinal axis, scattered x-rays are detected by the fiber optic bundles, to each of which is coupled a respective photodetector, to provide a measurement resolution, i.e., dq/q, where q is the momentum transferred from an incident x-ray to an x-ray scattering specimen, of 2% over two (2) orders of magnitude in reciprocal space, i.e., qmax/qmin approx=lO0.

Hessler, Jan P.

2004-06-15T23:59:59.000Z

333

Rise time measurement for ultrafast X-ray pulses  

Science Conference Proceedings (OSTI)

A pump-probe scheme measures the rise time of ultrafast x-ray pulses. Conventional high speed x-ray diagnostics (x-ray streak cameras, PIN diodes, diamond PCD devices) do not provide sufficient time resolution to resolve rise times of x-ray pulses on the order of 50 fs or less as they are being produced by modern fast x-ray sources. Here, we are describing a pump-probe technique that can be employed to measure events where detector resolution is insufficient to resolve the event. The scheme utilizes a diamond plate as an x-ray transducer and a p-polarized probe beam.

Celliers, Peter M. (Berkeley, CA); Weber, Franz A. (Oakland, CA); Moon, Stephen J. (Tracy, CA)

2005-04-05T23:59:59.000Z

334

Rise Time Measurement for Ultrafast X-Ray Pulses  

DOE Patents (OSTI)

A pump-probe scheme measures the rise time of ultrafast x-ray pulses. Conventional high speed x-ray diagnostics (x-ray streak cameras, PIN diodes, diamond PCD devices) do not provide sufficient time resolution to resolve rise times of x-ray pulses on the order of 50 fs or less as they are being produced by modern fast x-ray sources. Here, we are describing a pump-probe technique that can be employed to measure events where detector resolution is insufficient to resolve the event. The scheme utilizes a diamond plate as an x-ray transducer and a p-polarized probe beam.

Celliers, Peter M.; Weber, Franz A.; Moon, Stephen J.

2005-04-05T23:59:59.000Z

335

The Swift Gamma-Ray Burst Mission  

E-Print Network (OSTI)

The Swift mission, scheduled for launch in early 2004, is a multiwavelength observatory for gamma-ray burst (GRB) astronomy. It is the first-of-its-kind autonomous rapid-slewing satellite for transient astronomy and pioneers the way for future rapid-reaction and multiwavelength missions. It will be far more powerful than any previous GRB mission, observing more than 100 bursts per year and performing detailed X-ray and UV/optical afterglow observations spanning timescales from 1 minute to several days after the burst. The objectives are to determine the origin of GRBs; classify GRBs and search for new types; study the interaction of the ultra-relativistic outflows of GRBs with their surrounding medium; and use GRBs to study the early universe out to z>10. The mission is being developed by a NASA-led international collaboration. It will carry three instruments: a new-generation wide-field gamma-ray (15-150 keV) detector; a narrow-field X-ray telescope; and a narrow-field UV/optical telescope. Redshift determinations will be made for most bursts. In addition to the primary GRB science, the mission will perform a hard X-ray survey to a sensitivity of ~1 mCrab (~2x10^{-11} erg cm^{-2} s^{-1} in the 15-150 keV band), more than an order of magnitude better than HEAO A-4. A flexible data and operations system will allow rapid follow-up observations of all types of high-energy transients, with rapid data downlink and uplink available through the NASA TDRSS system. The mission is currently funded for 2 years of operations and the spacecraft will have a lifetime to orbital decay of ~8 years. [ABRIDGED

N. Gehrels; G Chincarini; P. Giommi; K. O. Mason; J. A. Nousek; A. A. Wells; N. E. White; S. D. Barthelmy; D. N. Burrows; L. R. Cominsky; K. C. Hurley; F. E. Marshall; P. Meszaros; P. W. A. Roming; Swift Science Team

2004-05-12T23:59:59.000Z

336

The Ptolemaic Gamma-Ray Burst Universe  

E-Print Network (OSTI)

The BATSE experiment on GRO has demonstrated the isotropic arrival directions and flat log N vs. log S of cosmic gamma-ray bursts. These data are best explained if the burst sources are distributed throughout an extended spherical Galactic halo, as previously suggested by Jennings. The halos radius is at least 40 Kpc, and probably is more than 100 Kpc. I consider possible origins of this halo, including primordial formation and neutron stars recoiling from their birthplaces in the Galactic disc. A simple geometrical model leads to a predicted relation between the dipole and quadrupole anisotropy. I suggest that neutron stars born with low recoil become millisecond pulsars, while those born with high recoil become the sources of gamma-ray bursts; these populations are nearly disjoint. Quiescent counterparts of gamma-ray bursts are predicted to be undetectably faint. 2 The first results from the BATSE on GRO (BATSE Science Team 1991) have revived the question of the distribution of gamma-ray burst sources in space. Their chief results, isotropy of gamma-ray burst directions and a log N vs. log S slope significantly flatter than-1.5, confirm earlier reports (see, for example, Meegan, Fishman and Wilson 1985 and the review by Cline 1984). Questions of relative calibration of different instruments and the paucity of good directional data permitted skepticism in the past. Such skepticism is no longer tenable, and the theoretical questions raised earlier must be faced. An isotropic distribution of sources implies that, out to the maximum distance of observation permitted by instrumental sensitivity, all directions contain equivalent source populations. The source population for an observed flux or fluence S is expressed as the integral N ( ? ?, S) =

J. I. Katz

1992-01-01T23:59:59.000Z

337

X-Ray Interactions with Matter  

DOE Data Explorer (OSTI)

The primary interactions of low-energy x-rays within condensed matter, viz. photoabsorption and coherent scattering, are described for photon energies outside the absorption threshold regions by using atomic scattering factors. The atomic scattering factors may be accurately determined from the atomic photoabsorption cross sections using modified Kramers-Kronig dispersion relations. From a synthesis of the currently available experimental data and recent theoretical calculations for photoabsorption, the angle-independent, forward-scattering components of the atomic scattering factors have been thus semiempirically determined and tabulated here for 92 elements and for the region 50-30,000 eV. Atomic scattering factors for all angles of coherent scattering and at the higher photon energies are obtained from these tabulated forward-scattering values by adding a simple angle-dependent form-factor correction. The incoherent scattering contributions that become significant for the light elements at the higher photon energies are similarly determined. The basic x-ray interaction relations that are used in applied x-ray physics are presented here in terms of the atomic scattering factors. The bulk optical constants are also related to the atomic scattering factors. These atomic and optical relations are applied to the detailed calculation of the reflectivity characteristics of a series of practical x-ray mirror, multilayer, and crystal monochromators. Comparisons of the results of this semiempirical,"atom-like", description of x-ray interactions for the low-energy region with those of experiment and ab initio theory are presented. (Taken from the abstract in OSTI Record 6131765) (Specialized Interface)

Henke, B.L.; Gullikson, E.M.; Davis, J.C.

338

X-ray imaging, spacecraft nuclear fission and cosmic ray contraband  

NLE Websites -- All DOE Office Websites (Extended Search)

R&D 100 Awards winners R&D 100 Awards winners X-ray imaging, spacecraft nuclear fission and cosmic ray contraband detection score R&D 100 awards R&D Magazine announced the winners and three technologies from Los Alamos National Laboratory and its partners are among the honorees. July 8, 2013 MiniMAX is a battery powered, digital x-ray imaging system that is completely self-contained, lightweight, compact and portable. MiniMAX is a battery powered, digital x-ray imaging system that is completely self-contained, lightweight, compact and portable. Contact Nancy Ambrosiano Communications Office (505) 667-0471 Email "The innovation and creativity shown in this year's awards is truly inspiring. It gives me great confidence in the Laboratory's intellectual vitality and ongoing role in national security science. Congratulations to

339

Collapsar accretion and the gamma-ray burst X-ray light curve.  

E-Print Network (OSTI)

??We present axisymmetric hydrodynamical simulations of the long-term accretion of a rotating gamma-ray burst progenitor star, a "collapsar," onto the central compact object, which we (more)

Lindner, Christopher Carl

2010-01-01T23:59:59.000Z

340

X-ray afterglows and spectroscopy of Gamma-Ray Bursts  

E-Print Network (OSTI)

I will review the constraints set by X-ray measurements of afterglows on several issues of GRB, with particular regard to the fireball model, the environment, the progenitor and dark GRB.

Luigi Piro

2004-02-26T23:59:59.000Z

Note: This page contains sample records for the topic "keynote ray mabus" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

**TITLE** ASP Conference Series, Vol. **VOLUME**, **PUBLICATION YEAR** **EDITORS** X-ray Transients from X-ray Binaries to Gamma Ray Bursts  

E-Print Network (OSTI)

Abstract. We discuss three classes of x-ray transients to highlight three new types of transients found with the Wide Field Cameras onboard BeppoSAX. First there are the transients related to Low Mass X-ray Binaries in outburst, typically lasting weeks to months and reaching luminosities of the Eddington limit for a few solar masses. Recently another subclass of outbursts in such binaries has been discovered, which are an order of magnitude fainter and last shorter than typical hours to days. We discuss whether they constitute a separate subset of x-ray binaries. A second class of x-ray transients are the x-ray bursts. Thermonuclear explosions on a neutron star (type I x-ray bursts) usually last of order minutes or less. We discovered a second type (called super x-ray bursts) with a duration of several hours. They relate to thermonuclear detonations much deeper in the neutron star atmosphere, possibly burning on the nuclear ashes of normal x-ray bursts. The third class are the enigmatic Fast X-ray Transients occurring at all galactic latitudes. We found that the bright ones are of two types only: either nearby coronal sources (lasting hours) or the socalled x-ray flashes (lasting minutes). The new class, the X-ray flashes, may be a new type of cosmic explosion, intermediate between supernovae and gamma ray bursts, or they may be highly redshifted gamma ray bursts. It thus appears that the three classes of x-ray transients each come in two flavors: long and short. 1.

John Heise; Jean In t Z

2001-01-01T23:59:59.000Z

342

High Energy Gamma-Ray Emission from Gamma-Ray Bursts - Before GLAST  

Science Conference Proceedings (OSTI)

Gamma-ray bursts (GRBs) are short and intense emission of soft {gamma}-rays, which have fascinated astronomers and astrophysicists since their unexpected discovery in 1960s. The X-ray/optical/radio afterglow observations confirm the cosmological origin of GRBs, support the fireball model, and imply a long-activity of the central engine. The high-energy {gamma}-ray emission (> 20 MeV) from GRBs is particularly important because they shed some lights on the radiation mechanisms and can help us to constrain the physical processes giving rise to the early afterglows. In this work, we review observational and theoretical studies of the high-energy emission from GRBs. Special attention is given to the expected high-energy emission signatures accompanying the canonical early-time X-ray afterglow that was observed by the Swift X-ray Telescope. We also discuss the detection prospect of the upcoming GLAST satellite and the current ground-based Cerenkov detectors.

Fan, Yi-Zhong; Piran, Tsvi

2011-11-29T23:59:59.000Z

343

The Animated Gamma-ray Sky Revealed by the Fermi Gamma-ray Space Telescope  

SciTech Connect

The Fermi Gamma-ray Space Telescope has been observing the sky in gamma-rays since August 2008. In addition to breakthrough capabilities in energy coverage (20 MeV-300 GeV) and angular resolution, the wide field of view of the Large Area Telescope enables observations of 20% of the sky at any instant, and of the whole sky every three hours. It has revealed a very animated sky with bright gamma-ray bursts flashing and vanishing in minutes, powerful active galactic nuclei flaring over hours and days, many pulsars twinkling in the Milky Way, and X-ray binaries shimmering along their orbit. Most of these variable sources had not been seen by the Fermi predecessor, EGRET, and the wealth of new data already brings important clues to the origin of the high-energy emission and particles powered by the compact objects. The telescope also brings crisp images of the bright gamma-ray emission produced by cosmic-ray interactions in the interstellar medium, thus allowing to measure the cosmic nuclei and electron spectra across the Galaxy, to weigh interstellar clouds, in particular in the dark-gas phase. The telescope sensitivity at high energy will soon provide useful constraints on dark-matter annihilations in a variety of environments. I will review the current results and future prospects of the Fermi mission.

Grenier, Isabelle (University Paris Diderot and CEA Saclay, France)

2009-04-01T23:59:59.000Z

344

Energy Determination of X-Ray Transition Energies Using the ...  

Science Conference Proceedings (OSTI)

... We chose to measure x-ray transition energies from NIST ... This resulted in the production of x-ray emission ... would yield not only an energy scale for ...

2012-10-02T23:59:59.000Z

345

Radiological Safety Training for Radiation-Producing (X-Ray)...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

for General Radiation Safety Installations Using Non-Medical X-Ray and Sealed Gamma-Ray Sources, Energies up to 10 MEV, ANSI Standard N43.3, American National Standards...

346

SLAC National Accelerator Laboratory - SLAC's X-ray Laser Explores...  

NLE Websites -- All DOE Office Websites (Extended Search)

X-ray Laser Explores Big Data Frontier By Glenn Roberts Jr. June 12, 2013 It's no surprise that the data systems for SLAC's Linac Coherent Light Source X-ray laser have drawn...

347

Biological Imaging by Soft X-Ray Diffraction Microscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Biological Imaging by Soft X-Ray Diffraction Microscopy Print Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in...

348

SLAC National Accelerator Laboratory - SLAC X-rays Help Discover...  

NLE Websites -- All DOE Office Websites (Extended Search)

which pulses 120 times a second. In the instant before the intense X-rays destroy a nanocrystal, detectors record a flash of X-ray diffraction information. Finally, scientists use...

349

Using Light to Control How X Rays Interact with Matter  

NLE Websites -- All DOE Office Websites (Extended Search)

Using Light to Control How X Rays Interact with Matter Using Light to Control How X Rays Interact with Matter Print Wednesday, 27 January 2010 00:00 Schemes that use one light...

350

Microstructural Mapping Using High-Energy X-Ray Scattering  

Science Conference Proceedings (OSTI)

Abstract Scope, Advanced characterization methods at the APS permit unique in- situ ... The combination of an undulator source, brilliance preserving optics and focusing .... Ultra-Small-Angle X-Ray ScatteringX-Ray Photon Correlation...

351

Automatic Creation of Object Hierarchies for Ray Tracing  

Science Conference Proceedings (OSTI)

Intersection calculations dominate the run time of canonical ray tracers. A common algorithm to reduce the number of intersection tests required is the intersection of rays with a tree of extents, rather than the whole database of objects. A shortcoming ...

Jeffrey Goldsmith; John Salmon

1987-05-01T23:59:59.000Z

352

Observation of the Crab Nebula in Soft Gamma Rays with the Nuclear Compton Telescope  

E-Print Network (OSTI)

Gamma-ray bursts . . . . . . . . . . . . . . . . . . . 1.268] G. J. Fishman. The gamma-ray burst capabilities of BATSEOlson. Observations of Gamma- Ray Bursts of Cosmic Origin.

Bandstra, Mark ShenYu

2010-01-01T23:59:59.000Z

353

The Multiwavelength Approach to Unidentified Gamma-Ray Sources  

E-Print Network (OSTI)

As the highest-energy photons, gamma rays have an inherent interest to astrophysicists and particle physicists studying high-energy, nonthermal processes. Gamma-ray telescopes complement those at other wavelengths, especially radio, optical, and X-ray, providing the broad, mutiwavelength coverage that has become such a powerful aspect of modern astrophysics. Multiwavelength techniques of various types have been developed to help identify and explore unidentified gamma-ray sources. This overview summarizes the ideas behind several of these methods.

David J. Thompson

2004-07-20T23:59:59.000Z

354

Strengthened lithium for x-ray blast windows  

Science Conference Proceedings (OSTI)

Lithium's high x-ray transparency makes it an attractive material for windows intended to protect soft x-ray diagnostics in high energy density experiments. Pure lithium is soft and weak, but lithium mixed with lithium hydride powder becomes harder and stronger, in principle without any additional x-ray absorption. A comparison with the standard material for x-ray windows, beryllium, suggests that lithium or lithium strengthened by lithium hydride may well be an excellent option for such windows.

Pereira, N. R. [Ecopulse Inc., P.O. Box 528, Springfield, Virginia 22150 (United States); Imam, M. A. [Materials Science and Technology Division, Naval Research Laboratory, Washington, DC 20375 (United States)

2008-05-15T23:59:59.000Z

355

Electron and X-Ray Microscopy: Structural Characterization of ...  

Science Conference Proceedings (OSTI)

Oct 28, 2009 ... Recent Advances in Structural Characterization of Materials: Electron and X-Ray Microscopy: Structural Characterization of Nanoscale...

356

BL Lacertae Objects and the Extragalactic Gamma-Ray Background  

E-Print Network (OSTI)

A tight correlation between gamma-ray and radio emission is found for a sample of BL Lacertae (BL Lac) objects detected by Fermi Gamma-ray Space Telescope (Fermi) and the Energetic Gamma-Ray Experiment Telescope (EGRET). The gamma-ray emission of BL Lac objects exhibits strong variability, and the detection rate of gamma-ray BL Lac objects is low, which may be related to the gamma-ray duty cycle of BL Lac objects. We estimate the gamma-ray duty cycle ~ 0.11, for BL Lac objects detected by EGRET and Fermi. Using the empirical relation of gamma-ray emission with radio emission and the estimated gamma-ray duty cycle, we derive the gamma-ray luminosity function (LF) of BL Lac objects from their radio LF. Our derived gamma-ray LF of BL Lac objects can almost reproduce that calculated with the recently released Fermi bright active galactic nuclei (AGN) sample. We find that about 45% of the extragalactic diffuse gamma-ray background (EGRB) is contributed by BL Lac objects. Combining the estimate of the quasar contri...

Li, Fan

2011-01-01T23:59:59.000Z

357

X-ray Microscopy and Imaging: 2-BM  

NLE Websites -- All DOE Office Websites (Extended Search)

BM BM Introduction The 2-BM beamline offers measurement capabilities for x-ray microtomography, x-ray topography and x-ray microdiffraction. X-ray microtomography and x-ray diffraction instruments are installed on separate optical tables for independent operation with fast switch over time. Optically-coupled high-resolution CCD system is used for microtomography and topography with up to 1 micron spatial resolution. X-ray microdiffraction setup consists of KB microfocussing mirrors (~3 micron minimum spot), four-circle Huber diffractometer, high-precision translation sample stage, two orthogonally-mounted video cameras for viewing sample, fluorescence detector (Si-drift diode) and diffraction detector (a scintillation detector or a CCD). Three different levels of monochromaticity are available. Conventional monochromatic x-rays from a double-bounced Si (111) crystal monochromator (DCM, D E/E=1E-4), wide band-pass monochromatic x-rays from a double multilayer monochromator (DMM, D E/E=1~4E-2) and pink beam. The available x-ray range is from 5 keV to 30 keV. The lower limit is due to the x-ray windows and the upper limit is due to the critical angle of the x-ray mirror. Two different coatings (Cr and Pt) for the x-ray mirror allow either 20 keV or 30 keV energy cutoff.

358

Phase Contrast Microscopy with Soft and Hard X-rays  

E-Print Network (OSTI)

Calibration ­ Uses up part of dynamic range · Solution: ­ Soft x-rays: Back side Illumination ­ Hard xPhase Contrast Microscopy with Soft and Hard X-rays Using a Segmented Detector Benjamin Hornberger ­ Phase Contrast 101 · A Segmented Detector for Hard X-ray Microprobes ­ Segmented Silicon Chip ­ Charge

Homes, Christopher C.

359

The Biggest Bangs The Mystery of Gamma-Ray Bursts,  

E-Print Network (OSTI)

wide field of view and high duty cycle Milagro is uniquely capable of searching for gamma-ray bursts of gamma-ray bursts have come from observa- tions of afterglows over a wide spectral range. This has allowed detailed modeling of gamma-ray burst afterglow properties both as a function of time

Katz, Jonathan I.

360

The Biggest Bangs The Mystery of Gamma-Ray Bursts,  

E-Print Network (OSTI)

Physique www.sciencedirect.com Gamma-ray burst studies in the SVOM era / ?tude des sursauts gamma à l s t r a c t Article history: Available online 13 April 2011 Keywords: Gamma-rays, bursts Stars Black by Elsevier Masson SAS. All rights reserved. 1. Introduction The field of gamma-ray bursts (GRBs) has rapidly

Katz, Jonathan I.

Note: This page contains sample records for the topic "keynote ray mabus" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Gamma-Ray Bursts Nuclear Test Ban Treaty, 1963  

E-Print Network (OSTI)

Lecture 18 Gamma-Ray Bursts #12;Nuclear Test Ban Treaty, 1963 First Vela satellite pair launched and their predecessors, Vela 4, discovered the first gamma-ray bursts. The discovery was announced by Klebesadel, Strong, and Olson (ApJ, 182, 85) in 1973. #12;First Gamma-Ray Burst The Vela 5 satellites functioned from July, 1969

Harrison, Thomas

362

X-rays Illuminate Ancient Archimedes Text  

NLE Websites -- All DOE Office Websites (Extended Search)

Related Links: Related Links: May 2005 Headlines TIP Article Press Release Walters Art Museum SSRL Home Page SLAC Home Page Stanford Home Page Tuesday, 31 May 2005 X-rays Illuminate Ancient Archimedes Text (contact: Uwe Bergmann, bergmann@slac.stanford.edu) Archimedes Figure Image provided by Will Noel, The Walters Art Museum An early transcription of Archimedes' mathematical theories has been brought to light through the probing of high-intensity x-rays at SSRL's BL6-2. The text contains part of the Method of Mechanical Theorems, one of Archimedes' most important works, which was probably copied out by a scribe in the tenth century. The parchment on which it was written was later scraped down and reused as pages in a twelfth century prayer book, producing a document known as a palimpsest (which comes from the Greek,

363

HIGH BRILLIANCE X-RAY SCATTERING FOR  

NLE Websites -- All DOE Office Websites (Extended Search)

BRILLIANCE X-RAY SCATTERING FOR BRILLIANCE X-RAY SCATTERING FOR LIFE SCIENCES (LIX) Group Leader: Lin Yang Proposal Team: O. Bilsel 1 , B. Hsiao 2 , H. Huang 3 , T. Irving 4 , A. Menzel 5 , L. Pollack 6 , C. Riekel 7 , J. Rubert 8 , H. Tsuruta 9 , L. Yang 10 1 University of Massachusetts, 2 Stony Brook University, 3 Rice University, 4 IIT, 5SLS, 6 Cornell University, 7 European Synchrotron Radiation Facility, 8 NEU, 9 Stanford Synchrotron Radiation Lightsource, 10 Brookhaven National Laboratory TECHNIQUES AND CAPABILITIES APPLICATIONS ADDITIONAL INFORMATION * Energy range 2-20keV using undulator source. Simultaneous SAXS/WAXS to cover 0.003-3Å -1 at 12keV with 1 micron spot size * Time-resolved solution scattering with resolution of (1) microseconds to milliseconds using continuous-flow mixing (5µm x 10µm spot size) and (2) milliseconds using stopped-

364

Neutron-driven gamma-ray laser  

DOE Patents (OSTI)

A lasing cylinder emits laser radiation at a gamma-ray wavelength of 0.87 {angstrom} when subjected to an intense neutron flux of about 400 eV neutrons. A 250 {angstrom} thick layer of Be is provided between two layers of 100 {angstrom} thick layer of {sup 57}Co and these layers are supported on a foil substrate. The coated foil is coiled to form the lasing cylinder. Under the neutron flux {sup 57}Co becomes {sup 58}Co by neutron absorption. The {sup 58}Co then decays to {sup 57}Fe by 1.6 MeV proton emission. {sup 57}Fe then transitions by mesne decay to a population inversion for lasing action at 14.4 keV. Recoil from the proton emission separates the {sup 57}Fe from the {sup 57}Co and into the Be, where Mossbauer emission occurs at a gamma-ray wavelength.

Bowman, C.D.

1989-03-28T23:59:59.000Z

365

Real time gamma-ray signature identifier  

DOE Patents (OSTI)

A real time gamma-ray signature/source identification method and system using principal components analysis (PCA) for transforming and substantially reducing one or more comprehensive spectral libraries of nuclear materials types and configurations into a corresponding concise representation/signature(s) representing and indexing each individual predetermined spectrum in principal component (PC) space, wherein an unknown gamma-ray signature may be compared against the representative signature to find a match or at least characterize the unknown signature from among all the entries in the library with a single regression or simple projection into the PC space, so as to substantially reduce processing time and computing resources and enable real-time characterization and/or identification.

Rowland, Mark (Alamo, CA); Gosnell, Tom B. (Moraga, CA); Ham, Cheryl (Livermore, CA); Perkins, Dwight (Livermore, CA); Wong, James (Dublin, CA)

2012-05-15T23:59:59.000Z

366

High resolution x-ray microscope  

Science Conference Proceedings (OSTI)

The authors present x-ray images of grid meshes and biological material obtained using a microspot x-ray tube with a multilayer optic and a 92-element parabolic compound refractive lens (CRL) made of a plastic containing only hydrogen and carbon. Images obtained using this apparatus are compared with those using an area source with a spherical lens and a spherical lens with multilayer condenser. The authors found the best image quality using the multilayer condenser with a parabolic lens, compared to images with a spherical lens and without the multilayer optics. The resolution was measured using a 155-element parabolic CRL and a multilayer condenser with the microspot tube. The experiment demonstrates about 1.1 {mu}m resolution.

Gary, C. K.; Park, H.; Lombardo, L. W.; Piestrup, M. A.; Cremer, J. T.; Pantell, R. H.; Dudchik, Y. I. [Adelphi Technology, Inc. 981-B Industrial Road, San Carlos, California 94070 (United States); Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States); Institute of Applied Physics Problems, Kurchatova 7, Minsk 220064 (Belarus)

2007-04-30T23:59:59.000Z

367

Neutron-driven gamma-ray laser  

DOE Patents (OSTI)

A lasing cylinder emits laser radiation at a gamma-ray wavelength of 0.87 .ANG. when subjected to an intense neutron flux of about 400 eV neutrons. A 250 .ANG. thick layer of Be is provided between two layers of 100 .ANG. thick layer of .sup.57 Co and these layers are supported on a foil substrate. The coated foil is coiled to form the lasing cylinder. Under the neutron flux .sup.57 Co becomes .sup.58 Co by neutron absorption. The .sup.58 Co then decays to .sup.57 Fe by 1.6 MeV proton emission. .sup.57 Fe then transitions by mesne decay to a population inversion for lasing action at 14.4 keV. Recoil from the proton emission separates the .sup.57 Fe from the .sup.57 Co and into the Be, where Mossbauer emission occurs at a gamma-ray wavelength.

Bowman, Charles D. (Los Alamos, NM)

1990-01-01T23:59:59.000Z

368

Quantitative Analysis of Mt. St. Helens Ash by X-Ray Diffraction and X-Ray Fluorescence Spectrometry  

Science Conference Proceedings (OSTI)

A quantitative study by x-ray diffraction, optical polarizing microscopy, and x-ray fluorescence spectrometry of fallout and ambient ash from three Mt. St. Helens eruptions has revealed a consistent picture of the mineralogical and elemental ...

Briant L. Davis; L. Ronald Johnson; Dana T. Griffen; William Revell Phillips; Robert K. Stevens; David Maughan

1981-08-01T23:59:59.000Z

369

Sample holder for x-ray diffractometry  

DOE Patents (OSTI)

A sample holder for use with x-ray diffractometers with the capability to rotate the sample, as well as to adjust the position of the sample in the x, y, and z directions. Adjustment in the x direction is accomplished through loosening set screws, moving a platform, and retightening the set screws. Motion translators are used for adjustment in the y and z directions. An electric motor rotates the sample, and receives power from the diffractometer.

Hesch, V.L.

1991-12-31T23:59:59.000Z

370

THE GAMMA-RAY BURST MYSTERY  

E-Print Network (OSTI)

Gamma-ray bursts are transient events from beyond the solar system. Besides the allure of their mysterious origin, bursts are physically fascinating because they undoubtedly require exotic physics. Optical transients coincident with burst positions show that some, and probably all, bursts originate at cosmological distances, and not from a large Galactic halo. Observations of these events spectral and temporal behavior will guide and constrain the study of the physical processes producing this extragalactic phenomenon. 1

David L. Band

1997-01-01T23:59:59.000Z

371

TENDER ENERGY X-RAY ABSORPTION  

NLE Websites -- All DOE Office Websites (Extended Search)

TENDER ENERGY X-RAY ABSORPTION TENDER ENERGY X-RAY ABSORPTION SPECTROSCOPY (TES) Project Team: S. Bare 1,2 , J. Brandes 3 , T. Buonassisi 4 , J. Chen 5,2 , M. Croft 6 , E. DiMasi 7 , A. Frenkel 8,2 , D. Hesterberg 9 , S. Hulbert 7,2 , S. Khalid 7 , S. Myneni 10 , P. Northrup 7,11 , E.T. Rasbury 11 , B. Ravel 12 , R. Reeder 11 , J. Rodriguez 7,2 , D. Sparks 5,13 , V. Stojanoff 7 , G. Waychunas 14 1 UOP LLC, 2 Synchrotron Catalysis Consortium, 3 Skidaway Inst. of Oceanography, 4 MIT Laboratory for Photovoltaics Research, 5 Univ. of Delaware, 6 Rutgers Univ., 7 Brookhaven National Lab, 8 Yeshiva Univ., 9 North Carolina State Univ., 10 Princeton Univ., 11 Stony Brook Univ., 12 NIST, 13 Delaware Environmental Inst., 14 Lawrence Berkeley National Lab TECHNIQUES: High performance and in-situ X-ray absorption spectroscopy and spatially-resolved XAS of

372

Hard X-ray Variability of AGN  

E-Print Network (OSTI)

Aims: Active Galactic Nuclei are known to be variable throughout the electromagnetic spectrum. An energy domain poorly studied in this respect is the hard X-ray range above 20 keV. Methods: The first 9 months of the Swift/BAT all-sky survey are used to study the 14 - 195 keV variability of the 44 brightest AGN. The sources have been selected due to their detection significance of >10 sigma. We tested the variability using a maximum likelihood estimator and by analysing the structure function. Results: Probing different time scales, it appears that the absorbed AGN are more variable than the unabsorbed ones. The same applies for the comparison of Seyfert 2 and Seyfert 1 objects. As expected the blazars show stronger variability. 15% of the non-blazar AGN show variability of >20% compared to the average flux on time scales of 20 days, and 30% show at least 10% flux variation. All the non-blazar AGN which show strong variability are low-luminosity objects with L(14-195 keV) < 1E44 erg/sec. Conclusions: Concerning the variability pattern, there is a tendency of unabsorbed or type 1 galaxies being less variable than the absorbed or type 2 objects at hardest X-rays. A more solid anti-correlation is found between variability and luminosity, which has been previously observed in soft X-rays, in the UV, and in the optical domain.

V. Beckmann; S. D. Barthelmy; T. J. -L. Courvoisier; N. Gehrels; S. Soldi; J. Tueller; G. Wendt

2007-09-14T23:59:59.000Z

373

A Theory of Gamma-Ray Bursts  

E-Print Network (OSTI)

We present a specific scenario for the link between GRB and hypernovae, based on Blandford-Znajek extraction of black-hole spin energy. Such a mechanism requires a high angular momentum in the progenitor object. The observed association of gamma-ray bursts with type Ibc supernovae leads us to consider massive helium stars that form black holes at the end of their lives as progenitors. We combine the numerical work of MacFadyen & Woosley with analytic calculations, to show that about 1E53 erg each are available to drive the fast GRB ejecta and the supernova. The GRB ejecta are driven by the power output through the open field lines, whereas the supernova is powered by closed filed lines and jet shocks. We also present a much simplified approximate derivation of these energetics. Helium stars that leave massive black-hole remnants in special ways, namely via soft X-ray transients or very massive WNL stars. Since binaries naturally have high angular momentum, we propose a link between black-hole transients and gamma-ray bursts. Recent observations of one such transient, GRO J1655-40/Nova Scorpii 1994, explicitly support this connection: its high space velocity indicates that substantial mass was ejected in the formation of the black hole, and the overabundance of alpha-nuclei, especially sulphur, indicates that the explosion energy was extreme, as in SN 1998bw/GRB 980425. (abstract shortened)

G. E. Brown; C. -H. Lee; R. A. M. J. Wijers; H. K. Lee; G. Israelian; H. A. Bethe

2000-03-23T23:59:59.000Z

374

Ultra High-Energy Cosmic Ray Observations  

E-Print Network (OSTI)

The year 2007 has furnished us with outstanding results about the origin of the most energetic cosmic rays: a flux suppression as expected from the GZK-effect has been observed in the data of the HiRes and Auger experiments and correlations between the positions of nearby AGN and the arrival directions of trans-GZK events have been observed by the Pierre Auger Observatory. The latter finding marks the beginning of ultra high-energy cosmic ray astronomy and is considered a major breakthrough starting to shed first light onto the sources of the most extreme particles in nature. This report summarizes those observations and includes other major advances of the field, mostly presented at the 30th International Cosmic Ray Conference held in Merida, Mexico, in July 2007. With increasing statistics becoming available from current and even terminated experiments, systematic differences amongst different experiments and techniques can be studied in detail which is hoped to improve our understanding of experimental tec...

Kampert, Karl-Heinz

2008-01-01T23:59:59.000Z

375

X-ray chemistry in envelopes around young stellar objects  

E-Print Network (OSTI)

We present chemical models of the envelope of a young stellar object (YSO) exposed to a central X-ray source. The models are applied to the massive star-forming region AFGL 2591 for different X-ray fluxes. The total X-ray ionization rate is dominated by the `secondary' ionization rate of H2 resulting from fast electrons. The carbon, sulphur and nitrogen chemistries are discussed. It is found that He+ and H3+ are enhanced and trigger a peculiar chemistry. Several molecular X-ray tracers are found and compared to tracers of the far ultraviolet (FUV) field. Like ultraviolet radiation fields, X-rays enhance simple hydrides, ions and radicals. In contrast to ultraviolet photons, X-rays can penetrate deep into the envelope and affect the chemistry even at large distances from the source. Whereas the FUV enhanced species cover a region of 200-300 AU, the region enhanced by X-rays is >1000 AU. Best-fit models for AFGL 2591 predict an X-ray luminosity LX > 1e+31 ergs/s with a hard X-ray spectrum TX > 3e+07 K. Furthermore, we find LX/Lbol ~ 1e-6. The chemistry of the bulk of the envelope mass is dominated by cosmic-ray induced reactions rather than by X-ray induced ionization for X-ray luminosities LX < 1e+33 ergs/s. The calculated line intensities of HCO+ and HCS+ show that high-J lines are more affected than lower J lines by the presence of X-rays due to their higher critical densities, and that such differences are detectable even with large aperture single-dish telescopes. Future instruments such as Herschel-HIFI or SOFIA will be able to observe X-ray enhanced hydrides whereas the sensitivity and spatial resolution of ALMA is well-suited to measure the size and geometry of the region affected by X-rays.

P. Staeuber; S. D. Doty; E. F. van Dishoeck; A. O. Benz

2005-06-14T23:59:59.000Z

376

The Universe Viewed in Gamma-Rays 1 Toward Ultra Short Gamma Ray Burst Ground Based De-  

E-Print Network (OSTI)

-TIME FERMI LARGE AREA TELESCOPE GAMMA-RAY BURST AFTERGLOWS C. A. Swenson1 , A. Maxham2 , P. W. A. Roming1 2010 June 11; published 2010 June 28 ABSTRACT GRB 090926A was detected by both the Gamma-ray Burst the predicted gamma-ray fluence, as would have been seen by the Burst Alert Telescope (BAT) on board Swift

Enomoto, Ryoji

377

Calibrating X-ray Imaging Devices for Accurate Intensity Measurement  

SciTech Connect

The purpose of the project presented is to develop methods to accurately calibrate X-ray imaging devices. The approach was to develop X-ray source systems suitable for this endeavor and to develop methods to calibrate solid state detectors to measure source intensity. NSTec X-ray sources used for the absolute calibration of cameras are described, as well as the method of calibrating the source by calibrating the detectors. The work resulted in calibration measurements for several types of X-ray cameras. X-ray camera calibration measured efficiency and efficiency variation over the CCD. Camera types calibrated include: CCD, CID, back thinned (back illuminated), front illuminated.

Haugh, M. J.

2011-07-28T23:59:59.000Z

378

SGARFACE: A Novel Detector For Microsecond Gamma Ray Bursts  

E-Print Network (OSTI)

The Short GAmma Ray Front Air Cherenkov Experiment (SGARFACE) is operated at the Whipple Observatory utilizing the Whipple 10m gamma-ray telescope. SGARFACE is sensitive to gamma-ray bursts of more than 100MeV with durations from 100ns to 35us and provides a fluence sensitivity as low as 0.8 gamma-rays per m^2 above 200MeV (0.05 gamma-rays per m^2 above 2GeV) and allows to record the burst time structure.

S. LeBohec; F. Krennrich; G. Sleege

2005-01-11T23:59:59.000Z

379

Background X-ray Spectrum of Radioactive Samples  

Science Conference Proceedings (OSTI)

An energy-dispersive X-ray spectrometer (EDS) is commonly used with a scanning electron microscope (SEM) to analyze the elemental compositions and microstructures of a variety of samples. For example, the microstructures of nuclear fuels are commonly investigated with this technique. However, the radioactivity of some materials introduces additional X-rays that contribute to the EDS background spectrum. These X-rays are generally not accounted for in spectral analysis software, and can cause misleading results. X-rays from internal conversion [1], Bremsstrahlung [2] radiation associated with alpha ionizations and beta particle interactions [3], and gamma rays from radioactive decay can all elevate the background of radioactive materials.

Shannon Yee; Dawn E. Janney

2008-02-01T23:59:59.000Z

380

SUPERORBITAL MODULATION OF X-RAY EMISSION FROM GAMMA-RAY BINARY LSI +61 303  

SciTech Connect

We report the discovery of a systematic constant time lag between the X-ray and radio flares of the gamma-ray binary LSI +61 303, persistent over a long, multi-year timescale. Using the data from the monitoring of the system by RXTE we show that the orbital phase of X-ray flares from the source varies from {phi}{sub X} {approx_equal} 0.35 to {phi}{sub X} {approx_equal} 0.75 on the superorbital 4.6 yr timescale. Simultaneous radio observations show that periodic radio flares always lag the X-ray flare by {Delta}{phi}{sub X-R} {approx_equal} 0.2. We propose that the constant phase lag corresponds to the time of flight of the high-energy particle-filled plasma blobs from inside the binary to the radio emission region at the distance of {approx}10 times the binary separation distance. We put forward a hypothesis that the X-ray bursts correspond to the moments of formation of plasma blobs inside the binary system.

Chernyakova, M. [School of Physical Sciences, Dublin City University, Glasnevin, Dublin 9 (Ireland); Neronov, A. [ISDC Data Center for Astrophysics, Chemin d'Ecogia 16, 1290 Versoix (Switzerland); Molkov, S.; Lutovinov, A. [Space Research Institute (IKI), 84/32 Profsoyuznaya Str., Moscow 117997 (Russian Federation); Malyshev, D. [Bogolyubov Institute for Theoretical Physics, 14-b Metrolohichna Street, Kiev 03680 (Ukraine); Pooley, G. [Astrophysics, Cavendish Laboratory, Cambridge CB3 0HE (United Kingdom)

2012-03-10T23:59:59.000Z

Note: This page contains sample records for the topic "keynote ray mabus" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

A Link between Prompt Optical and Prompt Gamma-Ray Emission in Gamma-Ray Bursts  

E-Print Network (OSTI)

The prompt optical emission that arrives with gamma-rays from a cosmic gamma-ray burst (GRB) is a signature of the engine powering the burst, the properties of the ultra-relativistic ejecta of the explosion, and the ejecta's interactions with the surroundings. Until now, only GRB 990123 had been detected at optical wavelengths during the burst phase. Its prompt optical emission was variable and uncorrelated with the prompt gamma-ray emission, suggesting that the optical emission was generated by a reverse shock arising from the ejecta's collision with the surrounding material. Here we report prompt optical emission from GRB 041219a. It is variable and correlated with the prompt gamma-rays, indicating a common origin for the optical light and the gamma-rays. Within the context of the standard fireball model of GRBs, we attribute this new optical component to internal shocks driven into the burst ejecta by variations of the inner engine. The correlated optical emission is a direct probe of the jet isolated from the medium. The timing of the uncorrelated optical emission is strongly dependent on the nature of the medium.

W. T. Vestrand; P. R. Wozniak; J. A. Wren; E. E. Fenimore; T. Sakamoto; R. R. White; D. Casperson; H. Davis; S. Evans; M. Galassi; K. E. McGowan; J. A. Schier; J. W. Asa; S. D. Barthelmy; J. R. Cummings; N. Gehrels; D. Hullinger; H. A. Krimm; C. B. Markwardt; K. McLean; D. Palmer; A. Parsons; J. Tueller

2005-03-23T23:59:59.000Z

382

TeV Burst of Gamma-Ray Bursts and Ultra High Energy Cosmic Rays  

E-Print Network (OSTI)

Some recent experiments detecting very high energy (VHE) gamma-rays above 10-20 TeV independently reported VHE bursts for some of bright gamma-ray bursts (GRBs). If these signals are truly from GRBs, these GRBs must emit a much larger amount of energy as VHE gamma-rays than in the ordinary photon energy range of GRBs (keV-MeV). We show that such extreme phenomena can be reasonably explained by synchrotron radiation of protons accelerated to \\sim 10^{20-21} eV, which has been predicted by Totani (1998a). Protons seem to carry about (m_p/m_e) times larger energy than electrons, and hence the total energy liberated by one GRB becomes as large as \\sim 10^{56} (\\Delta \\Omega / 4 \\pi) ergs. Therefore a strong beaming of GRB emission is highly likely. Extension of the VHE spectrum beyond 20 TeV gives a nearly model-independent lower limit of the Lorentz factor of GRBs, as $\\gamma \\gtilde 500$. Furthermore, our model gives the correct energy range and time variability of ordinary keV-MeV gamma-rays of GRBs by synchrotron radiation of electrons. Therefore the VHE bursts of GRBs strongly support the hypothesis that ultra high energy cosmic rays observed on the Earth are produced by GRBs.

Tomonori Totani

1998-10-14T23:59:59.000Z

383

Apparatus for monitoring x-ray beam alignment  

DOE Patents (OSTI)

A self-contained, hand-held apparatus is provided for monitoring alignment of an x-ray beam in an instrument employing an x-ray source. The apparatus includes a transducer assembly containing a photoresistor for providing a range of electrical signals responsive to a range of x-ray beam intensities from the x-ray beam being aligned. A circuit, powered by a 7.5 VDC power supply and containing an audio frequency pulse generator whose frequency varies with the resistance of the photoresistor, is provided for generating a range of audible sounds. A portion of the audible range corresponds to low x-ray beam intensity. Another portion of the audible range corresponds to high x-ray beam intensity. The transducer assembly may include an a photoresistor, a thin layer of x-ray fluorescent material, and a filter layer transparent to x-rays but opaque to visible light. X-rays from the beam undergoing alignment penetrate the filter layer and excite the layer of fluorescent material. The light emitted from the fluorescent material alters the resistance of the photoresistor which is in the electrical circuit including the audio pulse generator and a speaker. In employing the apparatus, the x-ray beam is aligned to a complete alignment by adjusting the x-ray beam to produce an audible sound of the maximum frequency.

Steinmeyer, P.A.

1989-09-12T23:59:59.000Z

384

Compton Recoil Electron Tracking With the TIGRE Gamma-Ray Balloon Experiment  

E-Print Network (OSTI)

AGNs), pulsars, gamma-ray bursts, cosmic ray interactionssensitive to cosmic gamma-ray bursts in the energy range ofGalactic center, a single gamma-ray burst which occurred 10

Kamiya, Kaoru

2011-01-01T23:59:59.000Z

385

GAMQUEST, a Computer Program to Identify Gamma Rays  

NLE Websites -- All DOE Office Websites (Extended Search)

GAMQUEST GAMQUEST A Computer Program to Identify Gamma Rays Edgardo Browne, Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 EBROWNE@LBL.Gov Table of Contents Introduction. Program Access and Output Files. How to Run GAMQUEST. From Individual Accounts. From Guest Account. Gamma-Ray Data. GAMQUEST, a Tool for Applied Research. Searching Strategies. Examples. Neutron Activation Analysis. Gamma-Ray Spectrum Between 100 and 800 keV. Gamma-Ray Spectrum Between 800 and 1600 keV. A List of X Rays and Gamma Rays from the Decay of 192Ir (74 hr). Run GAMQUEST from Guest Account Acknowledgments. References. 1. Introduction. The characteristic energies and intensities of gamma rays emitted by radioactive isotopes are commonly used as fingerprints for isotope

386

Direct detection of x-rays for protein crystallography  

DOE Patents (OSTI)

An apparatus and method for directly determining the crystalline structure of a protein crystal. The crystal is irradiated by a finely collimated x-ray beam. The interaction o f the x-ray beam with the crystal produces scattered x-rays. These scattered x-rays are detected by means of a large area, thick CCD which is capable of measuring a significant number of scattered x-rays which impact its surface. The CCD is capable of detecting the position of impact of the scattered x-ray on the surface of the CCD and the quantity of scattered x-rays which impact the same cell or pixel. This data is then processed in real-time and the processed data is outputted to produce an image of the structure of the crystal. If this crystal is a protein the molecular structure of the protein can be determined from the data received.

Atac, Muzaffer; McKay, Timothy

1997-12-01T23:59:59.000Z

387

Photon Sciences | Beamlines | HXN: Hard X-ray Nanoprobe  

NLE Websites -- All DOE Office Websites (Extended Search)

HXN: Hard X-ray Nanoprobe HXN: Hard X-ray Nanoprobe Poster | Fact Sheet | Preliminary Design Report Scientific Scope The Hard X-ray Nanoprobe beamline and endstation instruments (HXN) will be designed and constructed to explore new frontiers of hard x-ray microscopy applications with the highest achievable spatial resolution. Currently the available spatial resolution for scientific applications, provided by scanning x-ray microscopes in the hard x-ray regime, is limited to ~50nm, which is still insufficient for probing the nanoscale interfacial structures critical in determining properties and functionalities of material and biological systems. The HXN beamline aims to enable x-ray experiments at spatial resolutions ranging from 10 to 30 nm with an ultimate goal of ~1 nm. Beamline Description

388

Introduction to Neutron and X-Ray Scattering  

NLE Websites -- All DOE Office Websites (Extended Search)

Scattering Studies of Thin Scattering Studies of Thin Polymer Films Introduction to Neutron and X-Ray Scattering Sunil K. Sinha UCSD/LANL Acknowledgements: Prof. R.Pynn( Indiana U.) Prof. M.Tolan (U. Dortmund) Wilhelm Conrad Röntgen 1845-1923 1895: Discovery of X-Rays 1901 W. C. Röntgen in Physics for the discovery of x-rays. 1914 M. von Laue in Physics for x-ray diffraction from crystals. 1915 W. H. Bragg and W. L. Bragg in Physics for crystal structure determination. 1917 C. G. Barkla in Physics for characteristic radiation of elements. 1924 K. M. G. Siegbahn in Physics for x-ray spectroscopy. 1927 A. H. Compton in Physics for scattering of x-rays by electrons. 1936 P. Debye in Chemistry for diffraction of x-rays and electrons in gases.

389

Gamma-ray burst interaction with dense interstellar medium  

E-Print Network (OSTI)

Interaction of cosmological gamma ray burst radiation with the dense interstellar medium of host galaxy is considered. Gas dynamical motion of interstellar medium driven by gamma ray burst is investigated in 2D approximation for different initial density distributions of host galaxy matter and different total energy of gamma ray burst. The maximum velocity of motion of interstellar medium is $1.8\\cdot10^4$ km/s. Light curves of gamma ray burst afterglow are calculated for set of non homogeneous density, distribution gamma ray burst total energy, and different viewing angles. Spectra of gamma ray burst afterglow are modeled taking into account conversion of hard photons (soft X-ray, hard UV) to soft UV and optics photons.

Maxim Barkov; Gennady Bisnovatyi-Kogan

2004-10-07T23:59:59.000Z

390

GAMMA RAYS FROM STAR FORMATION IN CLUSTERS OF GALAXIES  

SciTech Connect

Star formation in galaxies is observed to be associated with gamma-ray emission, presumably from non-thermal processes connected to the acceleration of cosmic-ray nuclei and electrons. The detection of gamma rays from starburst galaxies by the Fermi Large Area Telescope (LAT) has allowed the determination of a functional relationship between star formation rate and gamma-ray luminosity. Since star formation is known to scale with total infrared (8-1000 {mu}m) and radio (1.4 GHz) luminosity, the observed infrared and radio emission from a star-forming galaxy can be used to quantitatively infer the galaxy's gamma-ray luminosity. Similarly, star-forming galaxies within galaxy clusters allow us to derive lower limits on the gamma-ray emission from clusters, which have not yet been conclusively detected in gamma rays. In this study, we apply the functional relationships between gamma-ray luminosity and radio and IR luminosities of galaxies derived by the Fermi Collaboration to a sample of the best candidate galaxy clusters for detection in gamma rays in order to place lower limits on the gamma-ray emission associated with star formation in galaxy clusters. We find that several clusters have predicted gamma-ray emission from star formation that are within an order of magnitude of the upper limits derived in Ackermann et al. based on non-detection by Fermi-LAT. Given the current gamma-ray limits, star formation likely plays a significant role in the gamma-ray emission in some clusters, especially those with cool cores. We predict that both Fermi-LAT over the course of its lifetime and the future Cerenkov Telescope Array will be able to detect gamma-ray emission from star-forming galaxies in clusters.

Storm, Emma M.; Jeltema, Tesla E.; Profumo, Stefano [Department of Physics, University of California, 1156 High Street, Santa Cruz, CA 95064 (United States)

2012-08-20T23:59:59.000Z

391

X-Ray Imaging Crystal Spectrometer for Extended X-Ray Sources  

DOE Patents (OSTI)

Spherically or toroidally curved, double focusing crystals are used in a spectrometer for X-ray diagnostics of an extended X-ray source such as a hot plasma produced in a tokamak fusion experiment to provide spatially and temporally resolved data on plasma parameters such as ion temperature, toroidal and poloidal rotation, electron temperature, impurity ion charge-state distributions, and impurity transport. The imaging properties of these spherically or toroidally curved crystals provide both spectrally and spatially resolved X-ray data from the plasma using only one small spherically or toroidally curved crystal, thus eliminating the requirement for a large array of crystal spectrometers and the need to cross-calibrate the various crystals.

Bitter, Manfred L.; Fraekel, Benjamin; Gorman, James L.; Hill, Kenneth W.; Roquemore, Lane A.; Stodiek, Wolfgang; Goeler, Schweickhard von

1999-05-01T23:59:59.000Z

392

Cryogenic detector development at LLNL: ultraviolet x-ray, gamma-ray and biomolecule spectroscopy  

SciTech Connect

We are developing low-temperature detectors for optical, ultraviolet, X-ray, and gamma-ray spectroscopy, and for biomolecular mass spectrometry. We present development work on these detectors and materials analysis and biomolecular mass spectrometry. We have measured thin-film Nb/Al/Al2O3/AlNb superconducting tunnel junction (STJ) X-ray detectors in the 0.2 to 1 keV band with a range of different junction sizes and aluminum film thicknesses. In one case, we have achieved the statistical limit to the energy resolution of 13 eV FWHM at 227 eV with an output count rate of 20,600 cts/s.

Labov, S.E.; Frank, M.; le Grand, J.B. [and others

1997-08-12T23:59:59.000Z

393

X-ray Lines in Gamma-ray Bursts and Cerenkov Line Mechanism  

E-Print Network (OSTI)

X-ray emission and absorption features are of great importance in our understanding the nature and environment of gamma-ray bursts (GRBs). So far, iron emission lines have been detected in at least four GRB afterglows. In this paper, the observational properties and physical constraints on materials surrounding GRB sources are reviewed, and several classes of theoretical models are also discussed. We will specially concentrate on the Cerenkov line mechanism, in which the broad iron lines are expected, and a small mass of Fe is required to produce the large line luminosity. In addition, our interpretation can favor the recent jet unified model for different classes of gamma-ray bursts with a standard energy reservoir.

Wei Wang

2004-07-30T23:59:59.000Z

394

EARLY THERMAL X-RAY EMISSION FROM LONG GAMMA-RAY BURSTS AND THEIR CIRCUMSTELLAR ENVIRONMENTS  

SciTech Connect

We performed a series of hydrodynamical calculations of an ultrarelativistic jet propagating through a massive star and the circumstellar matter (CSM) to investigate the interaction between the ejecta and the CSM. We succeed in distinguishing two qualitatively different cases in which the ejecta are shocked and adiabatically cool. To examine whether the cocoon expanding at subrelativistic speeds emits any observable signal, we calculate the expected photospheric emission from the cocoon. It is found that the emission can explain early thermal X-ray emission recently found in some long gamma-ray bursts (GRBs). The result implies that the difference of the circumstellar environment of long GRBs can be probed by observing their early thermal X-ray emission.

Suzuki, Akihiro [Center for Computational Astrophysics, National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan); Shigeyama, Toshikazu [Research Center for the Early Universe, School of Science, University of Tokyo, Bunkyo-ku, Tokyo 113-0033 (Japan)

2013-02-10T23:59:59.000Z

395

SWIFT X-RAY TELESCOPE MONITORING OF FERMI-LAT GAMMA-RAY SOURCES OF INTEREST  

Science Conference Proceedings (OSTI)

We describe a long-term Swift monitoring program of Fermi gamma-ray sources, particularly the 23 gamma-ray ''sources of interest''.We present a systematic analysis of the Swift X-Ray Telescope light curves and hardness ratios of these sources, and we calculate excess variability. We present data for the time interval of 2004 December 22 through 2012 August 31. We describe the analysis methods used to produce these data products, and we discuss the availability of these data in an online repository, which continues to grow from more data on these sources and from a growing list of additional sources. This database should be of use to the broad astronomical community for long-term studies of the variability of these objects and for inclusion in multiwavelength studies.

Stroh, Michael C.; Falcone, Abe D. [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States)

2013-08-15T23:59:59.000Z

396

Gamma Ray Bursts: recent results and connections to very high energy Cosmic Rays and Neutrinos  

E-Print Network (OSTI)

Gamma-ray bursts are the most concentrated explosions in the Universe. They have been detected electromagnetically at energies up to tens of GeV, and it is suspected that they could be active at least up to TeV energies. It is also speculated that they could emit cosmic rays and neutrinos at energies reaching up to the $10^{18}-10^{20}$ eV range. Here we review the recent developments in the photon phenomenology in the light of \\swift and \\fermi satellite observations, as well as recent IceCube upper limits on their neutrino luminosity. We discuss some of the theoretical models developed to explain these observations and their possible contribution to a very high energy cosmic ray and neutrino background.

Pter Mszros; Katsuaki Asano; Pter Veres

2012-09-11T23:59:59.000Z

397

Prompt TeV Emission from Cosmic Rays Accelerated by Gamma Ray Bursts Interacting with Surrounding Stellar Wind  

E-Print Network (OSTI)

Protons accelerated in the internal shocks of a long duration gamma ray burst can escape the fireball as cosmic rays by converting to neutrons. Hadronic interactions of these neutrons inside a stellar wind bubble created by the progenitor star will produce TeV gamma rays via neutral meson decay and synchrotron radiation by charged pion-decay electrons in the wind magnetic field. Such gamma rays should be observable from nearby gamma ray bursts by currently running and upcoming ground-based detectors.

Soebur Razzaque; Olga Mena; Charles D. Dermer

2008-10-07T23:59:59.000Z

398

(DOI: will be inserted by hand later) Light Curves of Swift Gamma Ray Bursts  

E-Print Network (OSTI)

Abstract. Recent observations from the Swift gamma ray burst explorer indicate that a large fraction of gamma ray bursts are characterized by a canonical behaviour of the X-ray afterglows. We present an effective theory which allows us to account for X-ray light curves of both gamma ray bursts and X-ray rich flashes. We propose that gamma ray bursts originate from massive magnetic powered pulsars. Key words. gamma-rays: bursts 1.

Paolo Cea

2006-01-01T23:59:59.000Z

399

High resolution x-ray and gamma ray imaging using diffraction lenses with mechanically bent crystals  

DOE Patents (OSTI)

A method for high spatial resolution imaging of a plurality of sources of x-ray and gamma-ray radiation is provided. High quality mechanically bent diffracting crystals of 0.1 mm radial width are used for focusing the radiation and directing the radiation to an array of detectors which is used for analyzing their addition to collect data as to the location of the source of radiation. A computer is used for converting the data to an image. The invention also provides for the use of a multi-component high resolution detector array and for narrow source and detector apertures.

Smither, Robert K. (Hinsdale, IL)

2008-12-23T23:59:59.000Z

400

GRB 070724B: the first Gamma Ray Burst localized by SuperAGILE and its Swift X-ray Afterglow  

E-Print Network (OSTI)

GRB 070724B is the first Gamma Ray Burst localized by SuperAGILE, the hard X-ray monitor aboard the AGILE satellite. The coordinates of the event were published $\\sim 19$ hours after the trigger. The Swift X-Ray Telescope pointed at the SuperAGILE location and detected the X-ray afterglow inside the SuperAGILE error circle. The AGILE gamma-ray Tracker and Minicalorimeter did not detect any significant gamma ray emission associated with GRB 070724B in the MeV and GeV range, neither prompt nor delayed. Searches of the optical afterglow were performed by the Swift UVOT and the Palomar automated 60-inch telescopes without any significant detection. Similarly the Very Large Array did not detect a radio afterglow. This is the first GRB event with a firm upper limit in the 100 MeV -- 30 GeV energy range, associated with an X-ray afterglow.

E. Del Monte; M. Feroci; L. Pacciani; Y. Evangelista; I. Donnarumma; P. Soffitta; E. Costa; I. Lapshov; F. Lazzarotto; M. Rapisarda; A. Argan; G. Barbiellini; M. Basset; A. Bulgarelli; P. Caraveo; A. Chen; G. Di Cocco; L. Foggetta; F. Fuschino; M. Galli; F. Gianotti; A. Giuliani; C. Labanti; P. Lipari; F. Longo; M. Marisaldi; F. Mauri; S. Mereghetti; A. Morselli; A. Pellizzoni; F. Perotti; P. Picozza; M. Prest; G. Pucella; M. Tavani; M. Trifoglio; A. Trois; E. Vallazza; S. Vercellone; V. Vittorini; A. Zambra; P. Romano; D. N. Burrows; G. Chincarini; N. Gehrels; V. La Parola; P. T. O'Brien; J. P. Osborne; B. Preger; C. Pittori; L. A. Antonelli; F. Verrecchia; P. Giommi; L. Salotti

2007-12-04T23:59:59.000Z

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401

THE NEW CANGAROO TELESCOPE AND THE PROSPECT OF VHE GAMMA RAY OBSERVATION AT  

E-Print Network (OSTI)

GammaWhat about Gamma--Ray Bursts?Ray Bursts? Extremely powerful explosions happen in galaxies The Quest for Gamma Rays:The Quest for Gamma Rays: Exploring the Most Violent PlacesExploring the Most is gammaWhat is gamma--ray background light like?ray background light like? How diffuse is the gamma

Enomoto, Ryoji

402

A Gamma-Ray Burst Trigger Toolkit  

E-Print Network (OSTI)

The detection rate of a gamma-ray burst detector can be increased by using a count rate trigger with many accumulation times ?t and energy bands ?E. Because a bursts peak flux varies when averaged over different ?t and ?E, the nominal sensitivity (the numerical value of the peak flux) of a trigger system is less important than how much fainter a burst could be at the detection threshold as ?t and ?E are changed. The relative sensitivity of different triggers can be quantified by referencing the detection threshold back to the peak flux for a fiducial value of ?t and ?E. This mapping between peak flux values for different sets of ?t and ?E varies from burst to burst. Quantitative estimates of the burst detection rate for a given detector and trigger system can be based on the observed rate at a measured peak flux value in this fiducial trigger. Predictions of a proposed triggers burst detection rate depend on the assumed burst population, and these predictions can be wildly in error for triggers that differ significantly from previous missions. I base the fiducial rate on the BATSE observations: 550 bursts per sky above a peak flux of 0.3 ph cm ?2 s ?1 averaged over ?t=1.024 s and ?E=50300 keV. Using a sample of 100 burst lightcurves I find that triggering on all possible values of ?t that are multiples of 0.064 s decreases the average threshold peak flux on the 1.024 s timescale by a factor of 0.6. Extending ?E to lower energies includes the large flux of the X-ray background, increasing the background count rate. Consequently a low energy ?E is advantageous only for very soft bursts. Whether a large fraction of the population of bright bursts is soft is disputed; the new population of X-ray Flashes is soft but relatively faint. Subject headings: gamma-rays: bursts

unknown authors

2002-01-01T23:59:59.000Z

403

Supersymmetry and the Cosmic Ray Positron Excess  

SciTech Connect

We explore several supersymmetric alternatives to explain predictions for the cosmic ray positron excess. Light sneutrino or neutralino LSP's, and a fine-tuned model designed to provide a delta-function input, can give adequate statistical descriptions of the reported HEAT data if non-thermal production of the relic cold dark matter density dominates and/or if"boost factors" (that could originate in uncertainties from propagation or local density fluctuations) to increase the size of the signal are included. All the descriptions can be tested at the Tevatron or LHC, and some in other WIMP detecting experiments.

Kane, Gordon L.; Wang, Lian-Tao; Wang, Ting T.

2002-02-15T23:59:59.000Z

404

Neutrino Event Rates from Gamma Ray Bursts  

E-Print Network (OSTI)

We recalculate the diffuse flux of high energy neutrinos produced by Gamma Ray Bursts (GRB) in the relativistic fireball model. Although we confirm that the average single burst produces only ~10^{-2} high energy neutrino events in a detector with 1 km^2 effective area, i.e. about 10 events per year, we show that the observed rate is dominated by burst-to-burst fluctuations which are very large. We find event rates that are expected to be larger by one order of magnitude, likely more, which are dominated by a few very bright bursts. This greatly simplifies their detection.

F. Halzen; D. W. Hooper

1999-08-12T23:59:59.000Z

405

Gamma-Ray Bursts observed by INTEGRAL  

E-Print Network (OSTI)

During the first six months of operations, six Gamma Ray Bursts (GRBs) have been detected in the field of view of the INTEGRAL instruments and localized by the INTEGRAL Burst Alert System (IBAS): a software for the automatic search of GRBs and the rapid distribution of their coordinates. I describe the current performances of IBAS and review the main results obtained so far. The coordinates of the latest burst localized by IBAS, GRB 031203, have been distributed within 20 s from the burst onset and with an uncertainty radius of only 2.7 arcmin.

S. Mereghetti

2003-12-12T23:59:59.000Z

406

Can Naked Singularities Yield Gamma Ray Bursts?  

E-Print Network (OSTI)

Gamma-ray bursts are believed to be the most luminous objects in the Universe. There has been some suggestion that these arise from quantum processes around naked singularities. The main problem with this suggestion is that all known examples of naked singularities are massless and hence there is effectively no source of energy. It is argued that a globally naked singularity coupled with quantum processes operating within a distance of the order of Planck length of the singularity will probably yield energy burst of the order of M_pc^2\\approx2\\times 10^{16} ergs, where M_p is the Planck mass.

H. M. Antia

1998-07-09T23:59:59.000Z

407

Gamma Ray Burst Neutrinos Probing Quantum Gravity  

E-Print Network (OSTI)

Very high energy, short wavelength, neutrinos may interact with the space-time foam predicted by theories of quantum gravity. They would propagate like light through a crystal lattice and be delayed, with the delay depending on the energy. This will appear to the observer as a violation of Lorenz invariance. Back of the envelope calculations imply that observations of neutrinos produced by gamma ray bursts may reach Planck-scale sensitivity. We revisit the problem considering two essential complications: the imprecise timing of the neutrinos associated with their poorly understood production mechanism in the source and the indirect nature of their energy measurement made by high energy neutrino telescopes.

M. C. Gonzalez-Garcia; F. Halzen

2006-11-28T23:59:59.000Z

408

Proton induced quasi-monochromatic x-ray beams for soft x-ray spectroscopy studies and selective x-ray fluorescence analysis  

Science Conference Proceedings (OSTI)

We present the analytical features and performance of an x-ray spectroscopy end station of moderate energy resolution operating with proton-induced quasi-monochromatic x-ray beams. The apparatus was designed, installed and operated at the 5.5 MV Tandem VdG Accelerator Laboratory of the Institute of Nuclear Physics, N.C.S.R. 'Demokritos,' Athens. The setup includes a two-level ultrahigh vacuum chamber that hosts in the lower level up to six primary targets in a rotatable holder; there, the irradiation of pure element materials-used as primary targets-with few-MeV high current ({approx}{mu}A) proton beams produces intense quasi-monochromatic x-ray beams of selectable energy. In the chamber's upper level, a six-position rotatable sample holder hosts the targets considered for x-ray spectroscopy studies. The proton-induced x-ray beam, after proper collimation, is guided to the sample position whereas various filters can be also inserted along the beam's path to eliminate the backscattered protons or/and to absorb selectively components of the x-ray beam. The apparatus incorporates an ultrathin window Si(Li) spectrometer (FWHM 136 eV at 5.89 keV) coupled with low-noise electronics capable of efficiently detecting photons down to carbon K{alpha}. Exemplary soft x-ray spectroscopy studies and results of selective x-ray fluorescence analysis are presented.

Sokaras, D. [Institute of Nuclear Physics, N.C.S.R. Demokritos, Aghia Paraskevi, 15310 Athens (Greece); Zarkadas, Ch. [PANalytical B.V., 7600 AA Almelo (Netherlands); Fliegauf, R.; Beckhoff, B. [Physikalisch-Technische Bundesanstalt, Abbestrasse 2-12, 10587 Berlin (Germany); Karydas, A. G. [Institute of Nuclear Physics, N.C.S.R. Demokritos, Aghia Paraskevi, 15310 Athens (Greece); Nuclear Spectrometry and Applications Laboratory, IAEA Laboratories, A-2444 Seibersdorf (Austria)

2012-12-15T23:59:59.000Z

409

X-ray follow-up observations of unidentified VHE gamma-ray sources  

E-Print Network (OSTI)

A large fraction of the recently discovered Galactic Very High Energy (VHE) source population remains unidentified to date. VHE gamma-ray emission traces high energy particles in these sources, but for example in case of hadronic processes also the gas density at the emission site. Moreover, the particles have sufficiently long lifetimes to be able to escape from their acceleration sites. Therefore, the gamma-ray sources or at least the areas of maximum surface brightness are in many cases spatially offset from the actual accelerators. A promising way to identify the objects in which the particles are accelerated seems to be to search for emission signatures of the acceleration process (like emission from shock-heated plasma). Also the particles themselves (through primary or secondary synchrotron emission) can be traced in lower wavebands. Those signatures are best visible in the X-ray band, and current X-ray observatories are well suited to conduct such follow-up observations. Some aspects of the current status of these investigations are reviewed.

Gerd Phlhofer

2008-11-23T23:59:59.000Z

410

High-Energy Cosmic Ray Event Data from the Pierre Auger Cosmic Ray Observatory  

DOE Data Explorer (OSTI)

The Pierre Auger Cosmic Ray Observatory in Mendoza, Argentina is the result of an international collaboration funded by 15 countries and many different organizations. Its mission is to capture high-energy cosmic ray events or air showers for research into their origin and nature. The Pierre Auger Collaboration agreed to make 1% of its data available to the public. The Public Event Explorer is a search tool that allows users to browse or search for and display figures and data plots of events collected since 2004. The repository is updated daily, and, as of July, 2009, makes 14,055 events publicly available. The energy of a cosmic ray is measured in Exa electron volts or EeV. These event displays can be browsed in order of their energy level from 0.1 to 41.1 EeV. Each event has an individual identification number.

The event displays provide station data, cosmic ray incoming direction, various energy measurements, plots, vector-based images, and an ASCII data file.

None

411

Ray River Geothermal Area | Open Energy Information  

Open Energy Info (EERE)

Page Page Edit with form History Facebook icon Twitter icon » Ray River Geothermal Area Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Geothermal Resource Area: Ray River Geothermal Area Contents 1 Area Overview 2 History and Infrastructure 3 Regulatory and Environmental Issues 4 Exploration History 5 Well Field Description 6 Geology of the Area 7 Geofluid Geochemistry 8 NEPA-Related Analyses (0) 9 Exploration Activities (0) 10 References Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"TERRAIN","zoom":6,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"500px","height":"300px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":65.96202521,"lon":-150.9200119,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

412

X-Ray Diffraction on NIF  

SciTech Connect

The National Ignition Facility (NIF) is currently a 192 beam, 1.6 MJ laser. NIF Ramp-Compression Experiments have already made the relevant exo-planet pressure range from 1 to 50 Mbar accessible. We Proposed to Study Carbon Phases by X-Ray Diffraction on NIF. Just a few years ago, ultra-high pressure phase diagrams for materials were very 'simple'. New experiments and theories point out surprising and decidedly complex behavior at the highest pressures considered. High pressures phases of aluminum are also predicted to be complex. Recent metadynamics survey of carbon proposed a dynamic pathway among multiple phases. We need to develop diagnostics and techniques to explore this new regime of highly compressed matter science. X-Ray Diffraction - Understand the phase diagram/EOS/strength/texture of materials to 10's of Mbar. Strategy and physics goals: (1) Powder diffraction; (2) Begin with diamond; (3) Continue with metals etc.; (4) Explore phase diagrams; (5) Develop liquid diffraction; and (6) Reduce background/improve resolution.

Eggert, J H; Wark, J

2012-02-15T23:59:59.000Z

413

Supermassive Objects as Gamma-Ray Bursters  

E-Print Network (OSTI)

We propose that the gravitational collapse of supermassive objects ($ M\\ga 10^4 M_\\odot$), either as relativistic star clusters or as single supermassive stars (which may result from stellar mergers in dense star clusters), could be a cosmological source of $\\gamma$-ray bursts. These events could provide the seeds of the supermassive black holes observed at the center of many galaxies. Collapsing supermassive objects will release a fraction of their huge gravitational binding energy as thermal neutrino pairs. We show that the accompanying neutrino/antineutrino annihilation-induced heating could drive electron/positron ``fireball'' formation, relativistic expansion, and associated $\\gamma$-ray emission. The major advantage of this model is its energetics: supermassive object collapses are far more energetic than solar mass-scale compact object mergers; therefore, the conversion of gravitational energy to fireball kinetic energy in the supermassive object scenario need not be highly efficient, nor is it necessary to invoke directional beaming. The major weakness of this model is difficulty in avoiding a baryon loading problem for one dimensional collapse scenarios.

George M. Fuller; Xiangdong Shi

1997-11-04T23:59:59.000Z

414

Two Classes of Gamma-Ray Bursts  

E-Print Network (OSTI)

If gamma-ray bursts are at cosmological distances, as suggested by their isotropy on the sky and the comparative deficiency of weak bursts, then they represent radiated energies of ? 1051 erg, and imply the release of an even greater energy. Only neutron stars and black holes have binding energies sufficient to power such extraordinarily violent and energetic events. General considerations of neutrino opacity imply1 that the escape of a neutron stars (or black holes) binding energy requires a time of about 10 sec, as shown by the observed duration of neutrino emission from SN1987A. The distribution of durations of gamma-ray bursts is known2 to be bimodal, with one peak between 10 and 100 sec and the other between 0.1 and 1 sec. We hypothesize that the durations of the longer bursts may be explained as the result of the diffusion of energy, by means of neutrinos, from a forming neutron star or black hole, but that the brevity of the shorter bursts requires different physics. An alternative hypothesis supposes that all bursts (excepting soft gamma repeaters, which we do not discuss) represent a single class of events, whose differing durations reflect differences in one or more parameters. These two hypotheses may be tested using data from the recently released 3B Catalogue3.

J. I. Katz; L. M. Canel

1995-01-01T23:59:59.000Z

415

A Theory of Gamma-Ray Bursts  

E-Print Network (OSTI)

We present a specific scenario for the link between GRB and hypernovae, based on Blandford-Znajek extraction of black-hole spin energy. Such a mechanism requires a high angular momentum in the progenitor object. The observed association of gamma-ray bursts with type Ibc supernovae leads us to consider massive helium stars that form black holes at the end of their lives as progenitors. We combine the numerical work of MacFadyen & Woosley with analytic calculations, to show that about 1E53 erg each are available to drive the fast GRB ejecta and the supernova. The GRB ejecta are driven by the power output through the open field lines, whereas the supernova is powered by closed filed lines and jet shocks. We also present a much simplified approximate derivation of these energetics. Helium stars that leave massive black-hole remnants in special ways, namely via soft X-ray transients or very massive WNL stars. Since binaries naturally have high angular momentum, we propose a link between black-hole transients a...

Brown, G E; Wijers, R A M J; Lee, H K; Israelian, G; Bethe, Hans Albrecht

2000-01-01T23:59:59.000Z

416

Tailored edge-ray reflectors for illumination  

SciTech Connect

The edge-ray principle can be used to tailor a reflector. However, one set of edge rays already fully determines the reflector profile. We present a design method for tailoring compact compound elliptical concentrator (CEC)-type reflectors to a given source and a desired angular power distribution. Two reflected images of the source, one on each side of the source, contribute together with the direct radiation from the source to produce the desired power distribution. We determine the reflector profile by numerically solving a differential equation. No optimization is required. Beyond the angular region in which the power distribution can be strictly controlled, the power drops to zero in a finite decay range. This decay range becomes narrower as the reflector increases in size. We show a reflector for producing a strictly constant irradiance from [minus] 43 to 43 deg from a cylindrical source of constant brightness. The reflector extends to a maximum distance of 8 source diameters. No power is radiated beyond [plus minus] 50 deg.

Ries, H.R.; Winston, R. (Enrico Fermi Institute and Department of Physics, The University of Chicago, Chicago, Illinois 60637 (United States))

1994-04-01T23:59:59.000Z

417

Possible association of ultra-high-energy cosmic-ray events with strong gamma-ray bursts  

E-Print Network (OSTI)

We point out that each of the error boxes of the two highest-energy cosmic-ray shower events known, overlaps with that of a strong gamma-ray burst (GRB). The GRBs precede the cosmic rays by 5.5, and 11 months respectively. In one case the strongest known cosmic ray is paired with the strongest gamma-ray burst in the BATSE catalogue. The probability of this to have occurred by chance seems rather small. Without building on post-factum statistics, we think the above is remarkable enough to suggest that the cosmic ray and gamma-ray burst were produced by the same outburst. A time delay (and a small positional disparity) is expected, since the trajectory of a charged cosmic-ray particle is wriggled by intervening magnetic fields. We estimate that the Galaxy's field alone may produce a delay of the order observed. We discuss some of the implications that follow if such an association is confirmed. For example, the upper limit on the distance to the cosmic-ray source, combined with a much-better-determined position of the gamma-ray burst source, narrows greatly the volume in which to look for an optical counterpart. There is also useful information in the time delay regarding, e.g., intergalactic magnetic fields.

Mordehai Milgrom; Vladimir Usov

1995-05-03T23:59:59.000Z

418

Study of Thick CZT Detectors for X-ray and Gamma-ray Astronomy  

Science Conference Proceedings (OSTI)

CdZnTe (CZT) is a wide bandgap II-VI semiconductor developed for the spectroscopic detection of X-rays and {gamma}-rays at room temperature. The Swift Burst Alert Telescope is using an 5240 cm{sup 2} array of 2 mm thick CZT detectors for the detection of 15-150 keV X-rays from Gamma-ray Bursts. We report on the systematic tests of thicker (0.5 cm) CZT detectors with volumes between 2 cm{sup 3} and 4 cm{sup 3} which are potential detector choices for a number of future X-ray telescopes that operate in the 10 keV to a few MeV energy range. The detectors contacted in our laboratory achieve Full Width Half Maximum energy resolutions of 2.7 keV (4.5%) at 59 keV, 3 keV (2.5%) at 122 keV and 4 keV (0.6%) at 662 keV. The 59 keV and 122 keV energy resolutions are among the world-best results for 0.5 cm thick CZT detectors. We use the data set to study trends of how the energy resolution depends on the detector thickness and on the pixel pitch. Unfortunately, we do not find clear trends, indicating that even for the extremely good energy resolutions reported here, the achievable energy resolutions are largely determined by the properties of individual crystals. Somewhat surprisingly, we achieve the reported results without applying a correction of the anode signals for the depth of the interaction. Measuring the interaction depths thus does not seem to be a pre-requisite for achieving sub-1% energy resolutions at 662 keV.

Li Q.; De Geronimo G.; Beilicke, M.; Lee, K.; Garson III, A.; Guo, Q.; Martin, J.; Yin, Y.; Dowkontt, P.; Jung, I.; Krawczynski, H.

2011-02-12T23:59:59.000Z

419

Biological Imaging by Soft X-Ray Diffraction Microscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Biological Imaging by Soft X-Ray Diffraction Microscopy Print Biological Imaging by Soft X-Ray Diffraction Microscopy Print Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in their ability to image with nanometer-scale resolution in three dimensions nonperiodic objects that are several microns in size. To fill this gap, the technique of coherent x-ray diffraction imaging now under development takes advantage of the penetrating power of x rays while simultaneously removing the limitations imposed by lens-based optical systems. Researchers from Stony Brook University, in collaboration with scientists at the ALS and Cornell University, have taken a large step in this direction by using a lensless x-ray diffraction microscope to image a freeze-dried yeast cell to better than 30-nm resolution. Images were made at several angular orientations of the cell.

420

Definition: X-Ray Diffraction (XRD) | Open Energy Information  

Open Energy Info (EERE)

X-Ray Diffraction (XRD) X-Ray Diffraction (XRD) Jump to: navigation, search Dictionary.png X-Ray Diffraction (XRD) X-Ray Diffraction (XRD) is a laboratory-based technique commonly used for identification of crystalline materials and analysis of unit cell dimensions. One of two primary types of XRD analysis (X-ray powder diffraction and single-crystal XRD) is commonly applied to samples to obtain specific information about the crystalline material under investigation. X-ray powder diffraction is widely used in geology, environmental science, material science, and engineering to rapidly identify unknown crystalline substances (typically in less than 20 minutes). A pure, finely ground, and homogenized sample is required for determination of the bulk composition. Additional uses include detailed

Note: This page contains sample records for the topic "keynote ray mabus" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

X-Ray Diffraction Microscopy of Magnetic Structures  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Diffraction Microscopy of Magnetic Structures Print X-Ray Diffraction Microscopy of Magnetic Structures Print science brief icon Scientists working at ALS Beamline 12.0.2.2 have demonstrated a new x-ray technique for producing short-exposure nanoscale images of the magnetic structure of materials. The new method combines aspects of coherent x-ray diffraction, which can determine 3-D charge distributions, and resonant magnetic scattering, which is sensitive to magnetic structures. Physicists have used coherent x-ray diffraction to measure the electron density of complicated molecules. The formula used to make these calculations contains terms that relate to the electron spin of magnetic atoms, but these terms are traditionally ignored since coherent x-ray diffraction has not been used to retrieve magnetic information. Using the full formula allows for the determination of not only the electron density, but also the magnetic spin distribution and its orientation.

422

X-Ray Diffraction (XRD) | Open Energy Information  

Open Energy Info (EERE)

X-Ray Diffraction (XRD) X-Ray Diffraction (XRD) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: X-Ray Diffraction (XRD) Details Activities (0) Areas (0) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Lab Analysis Techniques Exploration Sub Group: Rock Lab Analysis Parent Exploration Technique: Rock Lab Analysis Information Provided by Technique Lithology: Rapid and unambiguous identification of unknown minerals.[1] Stratigraphic/Structural: Hydrological: Thermal: Dictionary.png X-Ray Diffraction (XRD): X-Ray Diffraction (XRD) is a laboratory-based technique commonly used for identification of crystalline materials and analysis of unit cell dimensions. One of two primary types of XRD analysis (X-ray powder diffraction and single-crystal XRD) is commonly applied to samples to

423

Portable X-Ray Diffraction (XRD) | Open Energy Information  

Open Energy Info (EERE)

Portable X-Ray Diffraction (XRD) Portable X-Ray Diffraction (XRD) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Portable X-Ray Diffraction (XRD) Details Activities (0) Areas (0) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Field Techniques Exploration Sub Group: Data Collection and Mapping Parent Exploration Technique: Data Collection and Mapping Information Provided by Technique Lithology: Rapid and unambiguous identification of unknown minerals.[1] Stratigraphic/Structural: Hydrological: Thermal: Dictionary.png Portable X-Ray Diffraction (XRD): Portable X-Ray Diffraction (XRD) is a field-based technique that can be used for identification of crystalline materials and analysis of unit cell dimensions. Portable XRD analysis is similar to X-ray powder diffraction,

424

Biological Imaging by Soft X-Ray Diffraction Microscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Biological Imaging by Soft X-Ray Diffraction Microscopy Print Biological Imaging by Soft X-Ray Diffraction Microscopy Print Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in their ability to image with nanometer-scale resolution in three dimensions nonperiodic objects that are several microns in size. To fill this gap, the technique of coherent x-ray diffraction imaging now under development takes advantage of the penetrating power of x rays while simultaneously removing the limitations imposed by lens-based optical systems. Researchers from Stony Brook University, in collaboration with scientists at the ALS and Cornell University, have taken a large step in this direction by using a lensless x-ray diffraction microscope to image a freeze-dried yeast cell to better than 30-nm resolution. Images were made at several angular orientations of the cell.

425

Photon Sciences | Beamlines | IXS: Inelastic X-ray Scattering  

NLE Websites -- All DOE Office Websites (Extended Search)

IXS: Inelastic X-ray Scattering IXS: Inelastic X-ray Scattering Poster | Fact Sheet | Preliminary Design Report Scientific Scope Many hot topics related to the high frequency dynamics of condensed matter require both a narrower and steeper resolution function and access to a broader dynamic range than what are currently available. This represents a sort of "no man's land" that falls right in the dynamic gap lying between the high frequency spectroscopies, such as inelastic x-ray scattering (IXS), and the low frequency ones. New IXS spectrometers with improved energy and momentum resolutions would be required to fill this gap. To achieve this goal, a new x-ray optics concept for both the monochromatization and energy analysis of x-rays will be implemented at the NSLS-II Inelastic X-ray Scattering beamline. This solution exploits the

426

X-Ray Fluorescence (XRF) | Open Energy Information  

Open Energy Info (EERE)

X-Ray Fluorescence (XRF) X-Ray Fluorescence (XRF) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: X-Ray Fluorescence (XRF) Details Activities (0) Areas (0) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Lab Analysis Techniques Exploration Sub Group: Rock Lab Analysis Parent Exploration Technique: Rock Lab Analysis Information Provided by Technique Lithology: Bulk and trace element analysis of rocks, minerals, and sediments. Stratigraphic/Structural: Hydrological: Thermal: Dictionary.png X-Ray Fluorescence (XRF): X-Ray Fluorescence is a lab-based technique used for bulk chemical analysis of rock, mineral, sediment, and fluid samples. The technique depends on the fundamental principles of x-ray interactions with solid materials, similar

427

X-Ray Diffraction Microscopy of Magnetic Structures  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Diffraction Microscopy of Magnetic Structures Print X-Ray Diffraction Microscopy of Magnetic Structures Print science brief icon Scientists working at ALS Beamline 12.0.2.2 have demonstrated a new x-ray technique for producing short-exposure nanoscale images of the magnetic structure of materials. The new method combines aspects of coherent x-ray diffraction, which can determine 3-D charge distributions, and resonant magnetic scattering, which is sensitive to magnetic structures. Physicists have used coherent x-ray diffraction to measure the electron density of complicated molecules. The formula used to make these calculations contains terms that relate to the electron spin of magnetic atoms, but these terms are traditionally ignored since coherent x-ray diffraction has not been used to retrieve magnetic information. Using the full formula allows for the determination of not only the electron density, but also the magnetic spin distribution and its orientation.

428

Biological Imaging by Soft X-Ray Diffraction Microscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Biological Imaging by Soft X-Ray Diffraction Microscopy Print Biological Imaging by Soft X-Ray Diffraction Microscopy Print Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in their ability to image with nanometer-scale resolution in three dimensions nonperiodic objects that are several microns in size. To fill this gap, the technique of coherent x-ray diffraction imaging now under development takes advantage of the penetrating power of x rays while simultaneously removing the limitations imposed by lens-based optical systems. Researchers from Stony Brook University, in collaboration with scientists at the ALS and Cornell University, have taken a large step in this direction by using a lensless x-ray diffraction microscope to image a freeze-dried yeast cell to better than 30-nm resolution. Images were made at several angular orientations of the cell.

429

APS 7-BM Beamline: X-Ray Resources  

NLE Websites -- All DOE Office Websites (Extended Search)

Useful Websites Useful Websites X-Ray Interactions with Matter from CRXO at LBNL. Intuitive interface for x-ray transmission and reflectivity for a wide range of materials. X-Ray Data Booklet from LBNL. Slightly outdated in places, but many useful tables of edge energies, fluorescence lines, and crystal lattice spacings. NIST XCOM Database. Powerful database of photoelectric absorption, elastic scattering, and Compton scattering cross-sections for a wide range of materials. X-Ray Server. Maintained by Sergey Stepanov at GMCA at the APS, this website has several powerful calculators for simulating x-ray reflection and diffraction. Software X-Ray Oriented Programs (XOP). This program, written by scientists at the ESRF and APS, is widely used in the synchrotron research community.

430

Biological Imaging by Soft X-Ray Diffraction Microscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Biological Imaging by Soft X-Ray Diffraction Microscopy Print Biological Imaging by Soft X-Ray Diffraction Microscopy Print Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in their ability to image with nanometer-scale resolution in three dimensions nonperiodic objects that are several microns in size. To fill this gap, the technique of coherent x-ray diffraction imaging now under development takes advantage of the penetrating power of x rays while simultaneously removing the limitations imposed by lens-based optical systems. Researchers from Stony Brook University, in collaboration with scientists at the ALS and Cornell University, have taken a large step in this direction by using a lensless x-ray diffraction microscope to image a freeze-dried yeast cell to better than 30-nm resolution. Images were made at several angular orientations of the cell.

431

X-Ray Diffraction Microscopy of Magnetic Structures  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Diffraction Microscopy of Magnetic Structures Print X-Ray Diffraction Microscopy of Magnetic Structures Print science brief icon Scientists working at ALS Beamline 12.0.2.2 have demonstrated a new x-ray technique for producing short-exposure nanoscale images of the magnetic structure of materials. The new method combines aspects of coherent x-ray diffraction, which can determine 3-D charge distributions, and resonant magnetic scattering, which is sensitive to magnetic structures. Physicists have used coherent x-ray diffraction to measure the electron density of complicated molecules. The formula used to make these calculations contains terms that relate to the electron spin of magnetic atoms, but these terms are traditionally ignored since coherent x-ray diffraction has not been used to retrieve magnetic information. Using the full formula allows for the determination of not only the electron density, but also the magnetic spin distribution and its orientation.

432

Density gradient free electron collisionally excited x-ray laser  

DOE Patents (OSTI)

An operational x-ray laser is provided that amplifies 3p-3s transition x-ray radiation along an approximately linear path. The x-ray laser is driven by a high power optical laser. The driving line focused optical laser beam illuminates a free-standing thin foil that may be associated with a substrate for improved structural integrity. This illumination produces a generally cylindrically shaped plasma having an essentially uniform electron density and temperature, that exists over a long period of time, and provides the x-ray laser gain medium. The x-ray laser may be driven by more than one optical laser beam. The x-ray laser has been successfully demonstrated to function in a series of experimental tests.

Campbell, E.M.; Rosen, M.D.

1984-11-29T23:59:59.000Z

433

AGN models for the X and gamma-ray backgrounds  

E-Print Network (OSTI)

The origin of the X-ray background spectral intensity has been a long standing problem in high energy astrophysics research. Deep X-ray surveys carried out with ROSAT and ASCA combined with the broad band spectral results of Ginga and BeppoSAX satellites strongly support the hypothesis that the bulk of the X-ray background is due to the integrated contribution of discrete sources (mainly AGNs). At higher energies the unexpected findings of the Compton Gamma Ray Observatory indicate that also the gamma-ray background is likely to be due to AGNs. I will discuss AGN--based models for the high energy backgrounds and how future observations will improve our understanding of the X and gamma-ray backgrounds and of the physics and evolution of AGNs.

Andrea Comastri

1998-12-16T23:59:59.000Z

434

Fabrication process for a gradient index x-ray lens  

DOE Patents (OSTI)

A process for fabricating high efficiency x-ray lenses that operate in the 0.5-4.0 keV region suitable for use in biological imaging, surface science, and x-ray lithography of integrated circuits. The gradient index x-ray optics fabrication process broadly involves co-sputtering multi-layers of film on a wire, followed by slicing and mounting on block, and then ion beam thinning to a thickness determined by periodic testing for efficiency. The process enables the fabrication of transmissive gradient index x-ray optics for the 0.5-4.0 keV energy range. This process allows the fabrication of optical elements for the next generation of imaging and x-ray lithography instruments m the soft x-ray region.

Bionta, Richard M. (Livermore, CA); Makowiecki, Daniel M. (Livermore, CA); Skulina, Kenneth M. (Livermore, CA)

1995-01-01T23:59:59.000Z

435

Fabrication process for a gradient index x-ray lens  

DOE Patents (OSTI)

A process is disclosed for fabricating high efficiency x-ray lenses that operate in the 0.5-4.0 keV region suitable for use in biological imaging, surface science, and x-ray lithography of integrated circuits. The gradient index x-ray optics fabrication process broadly involves co-sputtering multi-layers of film on a wire, followed by slicing and mounting on block, and then ion beam thinning to a thickness determined by periodic testing for efficiency. The process enables the fabrication of transmissive gradient index x-ray optics for the 0.5-4.0 keV energy range. This process allows the fabrication of optical elements for the next generation of imaging and x-ray lithography instruments in the soft x-ray region. 13 figures.

Bionta, R.M.; Makowiecki, D.M.; Skulina, K.M.

1995-01-17T23:59:59.000Z

436

Multilayers for next generation x-ray sources  

Science Conference Proceedings (OSTI)

Multilayers are artificially layered structures that can be used to create optics and optical elements for a broad range of x-ray wavelengths, or can be optimized for other applications. The development of next generation x-ray sources (synchrotrons and x-ray free electron lasers) requires advances in x-ray optics. Newly developed multilayer-based mirrors and optical elements enabled efficient band-pass filtering, focusing and time resolved measurements in recent FLASH (Free Electron LASer in Hamburg) experiments. These experiments are providing invaluable feedback on the response of the multilayer structures to high intensity, short pulsed x-ray sources. This information is crucial to design optics for future x-ray free electron lasers and to benchmark computer codes that simulate damage processes.

Bajt, S; Chapman, H N; Spiller, E; Hau-Riege, S; Alameda, J; Nelson, A J; Walton, C C; Kjornrattanawanich, B; Aquila, A; Dollar, F; Gullikson, E; Tarrio, C

2007-05-04T23:59:59.000Z

437

Gamma Ray Bursts, Neutron Star Quakes, and the Casimir Effect  

E-Print Network (OSTI)

We propose that the dynamic Casimir effect is a mechanism that converts the energy of neutron starquakes into $\\gamma$--rays. This mechanism efficiently produces photons from electromagnetic Casimir energy released by the rapid motion of a dielectric medium into a vacuum. Estimates based on the cutoff energy of the gamma ray bursts and the volume involved in a starquake indicate that the total gamma ray energy emission is consonant with observational requirements.

C. Carlson; T. Goldman; J. Perez-Mercader

1994-11-25T23:59:59.000Z

438

CdZnTe technology for gamma ray detectors  

Science Conference Proceedings (OSTI)

CdZnTe detector technology has been developed at NASA Goddard for imaging and spectroscopy applications in hard x-ray and gamma ray astronomy. A CdZnTe strip detector array with capabilities for arc second imaging and spectroscopy has been built as a prototype for a space flight gamma ray burst instrument. CdZnTe detectors also have applications for medical imaging

Carl Stahle; Jack Shi; Peter Shu; Scott Barthelmy; Ann Parsons; Steve Snodgrass

1998-01-01T23:59:59.000Z

439

Nuclear Criticality as a Contributor to Gamma Ray Burst Events  

E-Print Network (OSTI)

Most gamma ray bursts are able to be explained using supernovae related phenomenon. Some measured results still lack compelling explanations and a contributory cause from nuclear criticality is proposed. This is shown to have general properties consistent with various known gamma ray burst properties. The galactic origin of fast rise exponential decay gamma ray bursts is considered a strong candidate for these types of events.

Robert Bruce Hayes

2013-01-15T23:59:59.000Z

440

Ultra-short wavelength x-ray system  

DOE Patents (OSTI)

A method and apparatus to generate a beam of coherent light including x-rays or XUV by colliding a high-intensity laser pulse with an electron beam that is accelerated by a synchronized laser pulse. Applications include x-ray and EUV lithography, protein structural analysis, plasma diagnostics, x-ray diffraction, crack analysis, non-destructive testing, surface science and ultrafast science.

Umstadter, Donald (Ann Arbor, MI); He, Fei (Ann Arbor, MI); Lau, Yue-Ying (Potomac, MD)

2008-01-22T23:59:59.000Z

Note: This page contains sample records for the topic "keynote ray mabus" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Inelastic cross sections from gamma-ray measurements  

Science Conference Proceedings (OSTI)

Measurements of gamma rays following neutron induced reactions have been studied with the Germanium Array for Neutron-induced Excitations (GEANIE) at the Los Alamos Neutron Science Center (LANSCE) for many years. Gamma-ray excitation functions and coincidence studies provide insight into nuclear reaction mechanisms as well as expanding our knowledge of energy levels and gamma-rays. Samples studied with Ge detectors at LANSCE range from Be to Pu. Fe, Cr and Ti have been considered for use as reference cross sections. An overview of the measurements and efforts to create a reliable neutron-induced gamma-ray reference cross section will be presented.

Nelson, Ronald Owen [Los Alamos National Laboratory

2010-12-06T23:59:59.000Z

442

NIST X-Ray Mass Attenuation Coefficients - Version History  

Science Conference Proceedings (OSTI)

... year, month day with database access date.) Hubbell, JH and Seltzer, SM (2004), Tables of X-Ray Mass Attenuation Coefficients and Mass Energy- ...

2010-10-05T23:59:59.000Z

443

4D Functional Materials Science with X-ray Microscopy  

Science Conference Proceedings (OSTI)

Ultrafast Electron Diffraction Studies of Lattice Dynamics in Thin Bismuth Films Understanding Fatigue and Corrosion-Fatigue Behavior by In Situ 3D X-ray...

444

Optical and X-ray Imaging Techniques for Material Characterization ...  

Science Conference Proceedings (OSTI)

Ultrafast X-ray and 2-dimensional UV Spectroscopy of TiO2 Nanoparticles: Majed Chergui1; 1Ecole Polytechnique Fdrale de Lausanne Mesoporous titanium...

445

X-Ray and Neutron Diffraction - Programmaster.org  

Science Conference Proceedings (OSTI)

Oct 20, 2010 ... Strain Determination in Nanoscale Microelectronic Materials Using X-Ray Diffraction: Conal Murray1; 1IBM T.J. Watson Research Center

446

Future Facilities for Gamma-Ray Pulsar Studies  

E-Print Network (OSTI)

Pulsars seen at gamma-ray energies offer insight into particle acceleration to very high energies, along with information about the geometry and interaction processes in the magnetospheres of these rotating neutron stars. During the next decade, a number of new gamma-ray facilities will become available for pulsar studies. This brief review describes the motivation for gamma-ray pulsar studies, the opportunities for such studies, and some specific discussion of the capabilities of the Gamma-ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT) for pulsar measurements.

D. J. Thompson

2003-10-17T23:59:59.000Z

447

High Temperature X-ray Diffraction Characterization of Thermal ...  

Science Conference Proceedings (OSTI)

Application of Conical Beam X-Ray Tomography to Multi-Phase Materials ... Digital Construction and Characterization of Reticulated Porous Microstructures...

448

Neutron and X-ray Scattering Investigations of Microscopic Energy ...  

Science Conference Proceedings (OSTI)

A Case Study in Future Energy Challenges: Towards In Situ Hard X-ray Microscopy of ... of Crystal Structure and Domain Character in Lead Free Piezoceramics.

449

APS X-ray Optics Fabrication and Characterization Facility  

SciTech Connect

The APS is in the process of assembling an X-ray Optics Fabrication and characterization Facility. This report will describe its current (as of February 1993) design.

Davey, S.

1993-02-01T23:59:59.000Z

450

The Diverse Environments of Gamma-Ray Bursts.  

E-Print Network (OSTI)

??I present results from several years of concerted observations of the afterglows and host galaxies of gamma-ray bursts (GRBs), the most energetic explosions in the (more)

Perley, Daniel Alan

2011-01-01T23:59:59.000Z

451

X-ray compass for determining device orientation  

DOE Patents (OSTI)

An apparatus and method for determining the orientation of a device with respect to an x-ray source are disclosed. In one embodiment, the present invention is coupled to a medical device in order to determine the rotational orientation of the medical device with respect to the x-ray source. In such an embodiment, the present invention is comprised of a scintillator portion which is adapted to emit photons upon the absorption of x-rays emitted from the x-ray source. An x-ray blocking portion is coupled to the scintillator portion. The x-ray blocking portion is disposed so as to vary the quantity of x-rays which penetrate the scintillator portion based upon the particular rotational orientation of the medical device with respect to the x-ray source. A photon transport mechanism is also coupled to the scintillator portion. The photon transport mechanism is adapted to pass the photons emitted from the scintillator portion to an electronics portion. By analyzing the quantity of the photons, the electronics portion determines the rotational orientation of the medical device with respect to the x-ray source. 25 figs.

Da Silva, L.B.; Matthews, D.L.; Fitch, J.P.; Everett, M.J.; Colston, B.W.; Stone, G.F.

1999-06-15T23:59:59.000Z

452

Synchrotron X-ray Studies of Supercritical Carbon Dioxide/ Reservoir...  

Open Energy Info (EERE)

Edit with form History Facebook icon Twitter icon Synchrotron X-ray Studies of Supercritical Carbon Dioxide Reservoir Rock Interfaces Geothermal Lab Call Project Jump to:...

453

Phase Sensitive X-ray Imager for More Accurate Digital ...  

Livermore Lab Report. News Archive. News ... use of higher energy X-rays which would result in a lower amount of absorbed radiation to the ... testing ...

454

X-Ray Scattering Group, Condensed Matter Physics & Materials...  

NLE Websites -- All DOE Office Websites (Extended Search)

Proceedings of the 12th International Clay Conference, Bahia Blanca, Argentina, July 22-28, 2001. Gibbs, D. X-ray magnetic scattering. Synchrotron Radiation News...

455

Neutron and X-Ray Studies of Advanced Materials IV  

Science Conference Proceedings (OSTI)

We propose to organize a seven-session Symposium on Neutron and X-Ray ... the advent of new powerful neutron sources such as the Spallation Neutron...

456

Available Technologies: High Temperature Strain Cell for X-ray ...  

High Temperature Strain Cell for X-ray ... Six hexapole infrared lamps focus inside the sample chamber onto a ceramic material sample with a spherical ...

457

X-ray compass for determining device orientation  

DOE Patents (OSTI)

An apparatus and method for determining the orientation of a device with respect to an x-ray source. In one embodiment, the present invention is coupled to a medical device in order to determine the rotational orientation of the medical device with respect to the x-ray source. In such an embodiment, the present invention is comprised of a scintillator portion which is adapted to emit photons upon the absorption of x-rays emitted from the x-ray source. An x-ray blocking portion is coupled to the scintillator portion. The x-ray blocking portion is disposed so as to vary the quantity of x-rays which penetrate the scintillator portion based upon the particular rotational orientation of the medical device with respect to the x-ray source. A photon transport mechanism is also coupled to the scintillator portion. The photon transport mechanism is adapted to pass the photons emitted from the scintillator portion to an electronics portion. By analyzing the quantity of the photons, the electronics portion determines the rotational orientation of the medical device with respect to the x-ray source.

Da Silva, Luiz B. (Danville, CA); Matthews, Dennis L. (Moss Beach, CA); Fitch, Joseph P. (Livermore, CA); Everett, Matthew J. (Pleasanton, CA); Colston, Billy W. (Livermore, CA); Stone, Gary F. (Livermore, CA)

1999-01-01T23:59:59.000Z

458

Inelastic X-ray Scattering Reveals Microscopic Transport Properties...  

NLE Websites -- All DOE Office Websites (Extended Search)

Inelastic X-ray Scattering Reveals Microscopic Transport Properties of Molten Aluminum Oxide The transport properties of high-temperature oxide melts are of considerable interest...

459

SLAC National Accelerator Laboratory - X-ray Laser Pulses in...  

NLE Websites -- All DOE Office Websites (Extended Search)

SLAC researchers have demonstrated for the first time how to produce pairs of X-ray laser pulses in slightly different wavelengths, or colors, with finely adjustable intervals...

460

NIST X-Ray Transition Energies Version History  

Science Conference Proceedings (OSTI)

... Jr., P. Indelicato, L. de Billy, E. Lindroth, and J. Anton, "X-ray transition energies: new approach to a ... [Type of medium] Available: URL [Access date]. ...

2010-10-05T23:59:59.000Z

Note: This page contains sample records for the topic "keynote ray mabus" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Optical and X-ray Imaging Techniques for Material Characterization  

Science Conference Proceedings (OSTI)

Hyperspectral CARS Microscopy in the Fingerprint Region In Situ X-ray ... Opportunities for Multimodal CARS Microscopy in Materials Science Photoemission...

462

Particle Accelerator & X-Ray Optics | Argonne National Laboratory  

NLE Websites -- All DOE Office Websites (Extended Search)

Hard X-Ray Quad Collimator Facilitates Microcrystallography Experiments Isotopic Abundance in Atom Trap Trace Analysis Nanomaterials Analysis using a Scanning Electron Microscope...

463

X RAY TU E WITH MAGNETI ELE TRON STEERING  

Sandia National Laboratories has created an improved efficiency compact X-ray source to address a wide range ... escape the anode and cause electron h ...

464

Temporal multiplexing radiography for dynamic x-ray imaging  

Science Conference Proceedings (OSTI)

All current x-ray imaging devices acquire images sequentially, one at a time. Using a spatially distributed multibeam x-ray source we recently demonstrated the feasibility for multiplexing x-ray imaging, which can significantly increase the data collection speed. Here we present a general methodology for dynamic x-ray imaging of an object in cyclic motion with temporal multiplexing. Compared to the conventional sequential imaging technique, where 2N-1 phase images are required and N exposures are needed for a single phase image, a temporal multiplexing of dimension 2N-1 can reduce the imaging time by a factor of N while maintaining the temporal resolution.

Cao Guohua [Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599 (United States); Zhang Jian [Department of Radiation Oncology and Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599 (United States); Zhou, Otto; Lu Jianping [Department of Physics and Astronomy and Curriculum in Applied Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina, 27599 (United States)

2009-09-15T23:59:59.000Z

465

Refractive Optics for Hard X-ray Transmission Microscopy  

Science Conference Proceedings (OSTI)

For hard x-ray transmission microscopy at photon energies higher than 15 keV we design refractive condenser and imaging elements to be used with synchrotron light sources as well as with x-ray tube sources. The condenser lenses are optimized for low x-ray attenuation--resulting in apertures greater than 1 mm--and homogeneous intensity distribution on the detector plane, whereas the imaging enables high-resolution (condenser and imaging lenses are being developed. The imaging lenses (compound refractive lenses, CRLs) are made of SU-8 negative resist by deep x-ray lithography. SU-8 shows high radiation stability. The fabrication technique enables high-quality lens structures regarding surface roughness and arrangement precision with arbitrary 2D geometry. To provide point foci, crossed pairs of lenses are used. Condenser lenses have been made utilizing deep x-ray lithographic patterning of thick SU-8 layers, too, whereas in this case, the aperture is limited due to process restrictions. Thus, in terms of large apertures, condenser lenses made of structured and rolled polyimide film are more attractive. Both condenser types, x-ray mosaic lenses and rolled x-ray prism lenses (RXPLs), are considered to be implemented into a microscope setup. The x-ray optical elements mentioned above are characterized with synchrotron radiation and x-ray laboratory sources, respectively.

Simon, M.; Last, A.; Mohr, J.; Nazmov, V.; Reznikova, E. [Institute for Microstructure Technology, Karlsruhe Institute of Technology Kaiserstrasse 12, 76131 Karlsruhe (Germany); Ahrens, G.; Voigt, A. [Microresist Technology, Koepenikerstrasse 325, 12555 Berlin (Germany)

2011-09-09T23:59:59.000Z

466

Astrophysical and Astrobiological effects of Gamma-Ray Bursts.  

E-Print Network (OSTI)

??O presente trabalho tem o objetivo principal de compreender os possveis efeitos da radiao energtica de um evento de Gamma-Ray Burst (GRB) sobre o meio (more)

Douglas Galante

2009-01-01T23:59:59.000Z

467

SLAC National Accelerator Laboratory - X-ray Science  

NLE Websites -- All DOE Office Websites (Extended Search)

energy technologies. SLAC's unique X-ray facilities - the Linac Coherent Light Source (LCLS) and the Stanford Synchrotron Radiation Lightsource (SSRL) - attract thousands of...

468

New Directions in X-ray Scattering - SSRL  

NLE Websites -- All DOE Office Websites (Extended Search)

associated with chemically and radioactively contaminated ground-water. Ability to probe weak scattering from single crystals as function of energy (resonance) and x-ray...

469

Bibliography of NRL Works on X-Ray Fluorescence Authored ...  

Science Conference Proceedings (OSTI)

... LS Birks, and EJ Brooks, "Grain-Boundary Diffusion of Zinc in Copper ... 111 J. Gilfrich, "X-Ray Diffraction Studies on the Titanium-Nickel System," in ...

2012-10-05T23:59:59.000Z

470

In situ X-ray Characterization of Energy Storage Materials |...  

NLE Websites -- All DOE Office Websites (Extended Search)

to accurately characterize the dynamic electrochemical processes at the nanometer and atomic level, we have employed a set of complementary, in situ X-ray characterization...

471

For Prospective Users: Learn about x-ray research  

NLE Websites -- All DOE Office Websites (Extended Search)

research in the fields of materials science; biological science; physics; chemistry; environmental, geophysical, and planetary science; and innovative x-ray instrumentation....

472

Staff at sector 30, inelastic x-ray scattering  

NLE Websites -- All DOE Office Websites (Extended Search)

Status and Schedule Safety and Training Divisions APS Engineering Support Division AES Groups Accelerator Systems Division ASD Groups X-ray Science Division XSD Groups...

473

Improved Treatment of X-ray Resistant & Inoperable Cancers ...  

If the electron beam can be transported to the internal cancer without exposure to tissue, ... This figure shows a comparison of X-ray radiation ...

474

Spatially-Resolved X-Ray Microdiffraction Studies Inside Individual ...  

Science Conference Proceedings (OSTI)

This talk will describe recent advances including increased scanning speed, and will describe the use of this x-ray microscope to study mesoscale structural...

475

Development of Coherent X-Ray Diffraction Microscopy and Its ...  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, 2010 TMS Annual Meeting & Exhibition. Symposium , Neutron and X-Ray Studies of Advanced Materials III. Presentation Title, 2010...

476

Grain Boundary Deformation Analyzed Via X-Ray Diffraction ...  

Science Conference Proceedings (OSTI)

Modeling the Influence of the Second Phase Particle Spatial Distribution on Recrystallization of AA 7050 Near-Field High Energy X-ray Diffraction Microscopy...

477

Applications of High Resolution X-ray Computed Tomography in ...  

Science Conference Proceedings (OSTI)

... data, including concentration profiles from x-ray absorption measurements during ... Dynamic Evolution of Liquid-liquid Phase Separation While Cooling in a

478

Determining the Uncertainty of X-Ray Absorption ...  

Science Conference Proceedings (OSTI)

... The apparatus uses a tungsten filament and a tungsten target to generate x rays and the detector contains a CZT crystal. ...

2005-01-28T23:59:59.000Z

479

X-ray Detection with Large Area Avalanche Photodiodes for ...  

Science Conference Proceedings (OSTI)

... The primary photon detector was a 12-element ... The overall energy range for the experiment was ... to directly detect X-rays with energies between 0.3 ...

2013-07-23T23:59:59.000Z

480

Spectrometry of X-Ray Beams Used for Calibrations  

Science Conference Proceedings (OSTI)

... and used to calibrate a wavelength-dispersive crystal x-ray spectrograph used by Lawrence Livermore National Laboratory (LLNL) to diagnose ...

2012-06-26T23:59:59.000Z

Note: This page contains sample records for the topic "keynote ray mabus" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


481

X-ray Tube with Magnetic Electron Steering - Energy ...  

The high average power large area X-ray tube provides ... Solar Photovoltaic; Solar ... Description This invention consists of a cathode and anode ...

482

Upgrade To The Pierre Auger Cosmic Ray Observatory's Lidar System.  

E-Print Network (OSTI)

??The Pierre Auger Cosmic Ray Observatory currently operates four elastic lidar systems in order to characterize the atmospheric aerosol content above the observatory. The atmospheric (more)

Petermann, Emily B

2010-01-01T23:59:59.000Z

483

X-ray Methods in High-Intensity Discharges and Metal-Halide Lamps: X-ray Induced Fluorescence  

SciTech Connect

We describe the use of x-ray induced fluorescence to study metal-halide high-intensity discharge lamps and to measure equilibrium vapor pressures of metal-halide salts. The physical principles of metal-halide lamps, relevant aspects of x-ray-atom interactions, the experimental method using synchrotron radiation, and x-ray induced fluorescence measurements relevant to metal-halide lamps are covered.

Curry, John J.; Lapatovich, Walter P.; Henins, Albert (NIST)

2011-12-09T23:59:59.000Z

484

No Evidence for Gamma-Ray Burst/Abell Cluster or Gamma- Ray Burst/Radio-Quiet Quasar Correlations  

E-Print Network (OSTI)

We examine the recent claims that cosmic gamma-ray bursts are associated with either radio-quiet quasars or Abell clusters. These associations were based on positional coincidences between cataloged quasars or Abell clusters, and selected events from the BATSE 3B catalog of gamma-ray bursts. We use a larger sample of gamma-ray bursts with more accurate positions, obtained by the 3rd Interplanetary Network, to re-evaluate these possible associations. We find no evidence for either.

K. Hurley; D. H. Hartmann; C. Kouveliotou; R. M. Kippen; J. Laros; T. Cline; M. Boer

1998-11-28T23:59:59.000Z

485

Variability of EGRET Gamma-Ray Sources  

E-Print Network (OSTI)

The variability of the high-energy gamma ray sources in the Third EGRET catalog is analyzed by a new method. We re-analyze the EGRET data to calculate a likelihood function for the flux of each source in each observation, both for detections and upper limits. These functions can be combined in a uniform manner with a simple model of the flux distribution to characterize the flux variation by a confidence interval for the relative standard deviation of the flux. The main result is a table of these values for almost all the cataloged sources. As expected, the identified pulsars are steady emitters and the blazars are mostly highly variable. The unidentified sources are heterogeneous, with greater variation at higher Galactic latitude. There is an indication that pulsar wind nebulae are associated with variable sources. There is a population of variable sources along the Galactic plane, concentrated in the inner spiral arms.

P. L. Nolan; W. F. Tompkins; I. A. Grenier; P. F. Michelson

2003-07-10T23:59:59.000Z

486

Short Gamma-Ray Bursts Are Different  

E-Print Network (OSTI)

We analyze BATSE time-tagged event (TTE) data for short gamma-ray bursts (T90 duration burst. Performing the cross-correlation between two energy bands, we measure an average lag ~ 20-40 x shorter than for long bursts, and a lag distribution close to symmetric about zero - unlike long bursts. Using a "Bayesian Block" method to identify significantly distinct pulse peaks, we find an order of magnitude fewer pulses than found in studies of long bursts. The disparity in lag magnitude is discontinuous across the ~ 2-s valley between long and short bursts. Thus, short bursts do not appear to be representable as a continuation of long bursts' temporal characteristics.

J. P. Norris; J. D. Scargle; J. T. Bonnell

2001-05-07T23:59:59.000Z

487

Millisecond Proto-Magnetars & Gamma Ray Bursts  

E-Print Network (OSTI)

In the seconds after core collapse and explosion, a thermal neutrino-driven wind emerges from the cooling, deleptonizing newly-born neutron star. If the neutron star has a large-scale magnetar-strength surface magnetic field and millisecond rotation period, then the wind is driven primarily by magneto-centrifugal slinging, and only secondarily by neutrino interactions. The strong magnetic field forces the wind to corotate with the stellar surface and the neutron star's rotational energy is efficiently extracted. As the neutron star cools, and the wind becomes increasingly magnetically-dominated, the outflow becomes relativistic. Here I review the millisecond magnetar model for long-duration gamma ray bursts and explore some of the basic physics of neutrino-magnetocentrifugal winds. I further speculate on some issues of collimation and geometry in the millisecond magnetar model.

Todd A. Thompson

2005-04-27T23:59:59.000Z

488

Perspectives on Gamma-Ray Pulsar Emission  

SciTech Connect

Pulsars are powerful sources of radiation across the electromagnetic spectrum. This paper highlights some theoretical insights into non-thermal, magnetospheric pulsar gamma-ray radiation. These advances have been driven by NASA's Fermi mission, launched in mid-2008. The Large Area Telescope (LAT) instrument on Fermi has afforded the discrimination between polar cap and slot gap/outer gap acceleration zones in young and middle-aged pulsars. Altitude discernment using the highest energy pulsar photons will be addressed, as will spectroscopic interpretation of the primary radiation mechanism in the LAT band, connecting to both polar cap/slot gap and outer gap scenarios. Focuses will mostly be on curvature radiation and magnetic pair creation, including population trends that may afford probes of the magnetospheric accelerating potential.

Baring, Matthew G. [Department of Physics and Astronomy, MS-108, Rice University, P. O. Box 1892, Houston, TX 77251-1892 (United States)

2011-09-21T23:59:59.000Z

489

Gray scale x-ray mask  

DOE Patents (OSTI)

The present invention describes a method for fabricating an embossing tool or an x-ray mask tool, providing microstructures that smoothly vary in height from point-to-point in etched substrates, i.e., structure which can vary in all three dimensions. The process uses a lithographic technique to transfer an image pattern in the surface of a silicon wafer by exposing and developing the resist and then etching the silicon substrate. Importantly, the photoresist is variably exposed so that when developed some of the resist layer remains. The remaining undeveloped resist acts as an etchant barrier to the reactive plasma used to etch the silicon substrate and therefore provides the ability etch structures of variable depths.

Morales, Alfredo M. (Livermore, CA); Gonzales, Marcela (Seattle, WA)

2006-03-07T23:59:59.000Z

490

Constraining Lorentz violations with Gamma Ray Bursts  

E-Print Network (OSTI)

Gamma ray bursts are excellent candidates to constrain physical models which break Lorentz symmetry. We consider deformed dispersion relations which break the boost invariance and lead to an energy-dependent speed of light. In these models, simultaneously emitted photons from cosmological sources reach Earth with a spectral time delay that depends on the symmetry breaking scale. We estimate the possible bounds which can be obtained by comparing the spectral time delays with the time resolution of available telescopes. We discuss the best strategy to reach the strongest bounds. We compute the probability of detecting bursts that improve the current bounds. The results are encouraging. Depending on the model, it is possible to build a detector that within several years will improve the present limits of 0.015 m_pl.

Maria Rodriguez Martinez; Tsvi Piran

2006-01-10T23:59:59.000Z

491

The Revival of Galactic Cosmic Ray Nucleosynthesis?  

E-Print Network (OSTI)

Because of the roughly linear correlation between Be/H and Fe/H in low metallicity halo stars, it has been argued that a ``primary'' component in the nucleosynthesis of Be must be present in addition to the ``secondary'' component from standard Galactic cosmic ray nucleosynthesis. In this paper we critically re-evaluate the evidence for the primary versus secondary character of Li, Be, and B evolution, analyzing both in the observations and in Galactic chemical evolution models. While it appears that [Be/H] versus [Fe/H] has a logarithmic slope near 1, it is rather the Be-O trend that directly arises from the physics of spallation production. Using new abundances for oxygen in halo stars based on UV OH lines, we find that the Be-O slope has a large uncertainty due to systematic effects, rendering it difficult to distinguish from the data between the secondary slope of 2 and the primary slope of 1. The possible difference between the Be-Fe and Be-O slopes is a consequence of the variation in O/Fe versus Fe: recent data suggests a negative slope rather than zero (i.e., Fe $\\propto$ O) as is often assumed. In addition to a phenomenological analysis of Be and B evolution, we have also examined the predicted LiBeB, O, and Fe trends in Galactic chemical evolution models which include outflow. Based on our results, it is possible that a good fit to the LiBeB evolution requires only traditional the Galactic cosmic ray spallation, and the (primary) neutrino-process contribution to B11. We thus suggest that these two processes might be sufficient to explain Li6, Be, and B evolution in the Galaxy, without the need for an additional primary source of Be and B.

Brian D. Fields; Keith A. Olive

1998-09-22T23:59:59.000Z

492

LONG GAMMA-RAY TRANSIENTS FROM COLLAPSARS  

Science Conference Proceedings (OSTI)

In the collapsar model for common gamma-ray bursts (GRBs), the formation of a centrifugally supported disk occurs during the first {approx}10 s following the collapse of the iron core in a massive star. This only occurs in a small fraction of massive stellar deaths, however, and requires unusual conditions. A much more frequent occurrence could be the death of a star that makes a black hole and a weak or absent outgoing shock, but in a progenitor that only has enough angular momentum in its outermost layers to make a disk. We consider several cases where this is likely to occur-blue supergiants with low mass-loss rates, tidally interacting binaries involving either helium stars or giant stars, and the collapse to a black hole of very massive pair-instability supernovae. These events have in common the accretion of a solar mass or so of material through a disk over a period much longer than the duration of a common GRB. A broad range of powers is possible, 10{sup 47}-10{sup 50} erg s{sup -1}, and this brightness could be enhanced by beaming. Such events were probably more frequent in the early universe where mass-loss rates were lower. Indeed, this could be one of the most common forms of gamma-ray transients in the universe and could be used to study first generation stars. Several events could be active in the sky at any one time. Recent examples of this sort of event may have been the Swift transients Sw-1644+57, Sw-2058+0516, and GRB 101225A.

Woosley, S. E. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Heger, Alexander, E-mail: woosley@ucolick.org, E-mail: alex@physics.umn.edu [Minnesota Institute of Astrophysics, School of Physics and Astronomy, University of Minnesota, Twin Cities, Minneapolis, MN 55455 (United States)

2012-06-10T23:59:59.000Z

493

The Collimation Signatures of Gamma-Ray Bursts: Jet Properties and Energetic Inferred from X-ray Afterglow Observations.  

E-Print Network (OSTI)

??Our understanding of gamma-ray bursts (GRBs) and their afterglows has progressed dramatically over the last few years thanks to the Swift mission and progress in (more)

Racusin, Judith

2009-01-01T23:59:59.000Z

494

Magnetic Structures in Gamma-Ray Burst Jets Probed by Gamma-Ray Polarization  

E-Print Network (OSTI)

We report polarization measurements in two prompt emissions of gamma-ray bursts, GRB 110301A and GRB 110721A, observed with the Gamma-ray burst polarimeter (GAP) aboard IKAROS solar sail mission. We detected linear polarization signals from each burst with polarization degree of $\\Pi = 70 \\pm 22$% with statistical significance of $3.7 \\sigma$ for GRB 110301A, and $\\Pi = 84^{+16}_{-28}$% with $3.3 \\sigma$ confidence level for GRB 110721A. We did not detect any significant change of polarization angle. These two events had shorter durations and dimmer brightness compared with GRB 100826A, which showed a significant change of polarization angle, as reported in Yonetoku et al. (2011). Synchrotron emission model can be consistent with all the data of the three GRBs, while photospheric quasi-thermal emission model is not favorable. We suggest that magnetic field structures in the emission region are globally-ordered fields advected from the central engine.

Daisuke Yonetoku; Toshio Murakami; Shuichi Gunji; Tatehiro Mihara; Kenji Toma; Yoshiyuki Morihara; Takuya Takahashi; Yudai Wakashima; Hajime Yonemochi; Tomonori Sakashita; Noriyuki Toukairin; Hirofumi Fujimoto; Yoshiki Kodama

2012-08-27T23:59:59.000Z

495

MAGNETIC STRUCTURES IN GAMMA-RAY BURST JETS PROBED BY GAMMA-RAY POLARIZATION  

SciTech Connect

We report polarization measurements in two prompt emissions of gamma-ray bursts, GRB 110301A and GRB 110721A, observed with the gamma-ray burst polarimeter (GAP) on borad the IKAROS solar sail mission. We detected linear polarization signals from each burst with polarization degree of {Pi} = 70 {+-} 22% with statistical significance of 3.7{sigma} for GRB 110301A, and {Pi} = 84{sup +16}{sub -28}% with 3.3{sigma} confidence level for GRB 110721A. We did not detect any significant change of polarization angle. These two events had shorter durations and dimmer brightness compared with GRB 100826A, which showed a significant change of polarization angle, as reported in Yonetoku et al. Synchrotron emission model can be consistent with the data of the three GRBs, while the photospheric quasi-thermal emission model is not favored. We suggest that magnetic field structures in the emission region are globally ordered fields advected from the central engine.

Yonetoku, Daisuke; Murakami, Toshio; Morihara, Yoshiyuki; Takahashi, Takuya; Wakashima, Yudai; Yonemochi, Hajime; Sakashita, Tomonori; Fujimoto, Hirofumi; Kodama, Yoshiki [College of Science and Engineering, School of Mathematics and Physics, Kanazawa University, Kakuma, Kanazawa, Ishikawa 920-1192 (Japan); Gunji, Shuichi; Toukairin, Noriyuki [Department of Physics, Faculty of Science, Yamagata University, 1-4-12, Koshirakawa, Yamagata, Yamagata 990-8560 (Japan); Mihara, Tatehiro [Cosmic Radiation Laboratory, RIKEN, 2-1, Hirosawa, Wako City, Saitama 351-0198 (Japan); Toma, Kenji, E-mail: yonetoku@astro.s.kanazawa-u.ac.jp [Department of Earth and Space Science, Osaka University, Toyonaka 560-0043 (Japan)

2012-10-10T23:59:59.000Z

496

X-ray Spectral Characteristics of GINGA Gamma-Ray Bursts  

E-Print Network (OSTI)

We have investigated the spectral characteristics of a sample of bright ?-ray bursts detected with the ?-ray burst sensors aboard the satellite Ginga. This instrument employed a proportional and scintillation counter to provide sensitivity to photons in the 2- 400 keV region and as such provided a unique opportunity to characterize the largely unexplored X-ray properties of ?-ray bursts. The photon spectra of the Ginga bursts are well described by a low energy slope, a bend energy, and a high energy slope. In the energy range where they can be compared, this result is consistent with burst spectral analyses obtained from the BATSE experiment aboard the Compton Observatory. However, below 20 keV we find evidence for a positive spectral number index in approximately 40 % of our burst sample, with some evidence for a strong rolloff at lower energies in a few events. There is a correlation (Pearsons r =-0.62) between the low energy slope and the bend energy. We find that the distribution of spectral bend energies extends below 10 keV. There has been some concern in cosmological models of GRBs that the bend energy covers only a small dynamic range. Our result extends the observed dynamic range and, since we observe bend energies down to the limit of our instrument, perhaps observations have not yet limited the range. The Ginga trigger range was virtually the same as BATSEs, yet we find a different range of fit parameters. One possible explanation might be that GRBs have two break energies, one often in the 50 to 500 keV range and the other near 5 keV. Both BATSE and Ginga fit with only a single break energy so BATSE tends to find breaks near the center of its

T. E. Strohmayer; E. E. Fenimore; T. Murakami; A. Yoshida

1997-01-01T23:59:59.000Z

497

X-ray spectroscopy of gamma-ray bursts: the path to the progenitor  

E-Print Network (OSTI)

Despite great observational and theoretical effort, the burst progenitor is still a mysterious object. It is generally accepted that one of the best ways to unveil its nature is the study of the properties of the close environment in which the explosion takes place. We discuss the potentiality and feasibility of time resolved X-ray spectroscopy, focusing on the prompt gamma-ray phase. We show that the study of absorption features (or continuum absorption) can reveal the radial structure of the close environment, unaccessible with different techniques. We discuss the detection of absorption in the prompt and afterglow spectra of several bursts, showing how these are consistent with gamma-ray bursts taking place in dense regions. In particular, we show that the radius and density of the surrounding cloud can be measured through the evolution of the column density in the prompt burst phase. The derived cloud properties are similar to those of the star forming cocoons and globules within molecular clouds. We conclude that the burst are likely associated with the final evolutionary stages of massive stars.

Davide Lazzati; Rosalba Perna; Gabriele Ghisellini

2002-01-17T23:59:59.000Z

498

Galactic gamma-ray bursters - an alternative source of cosmic rays at all energies  

E-Print Network (OSTI)

We propose a new hypothesis for the origin of the major part of non-solar hadronic cosmic rays (CRs) at all energies: highly relativistic, narrowly collimated jets from the birth or collapse of neutron stars (NSs) in our Galaxy accelerate ambient disk and halo matter to CR energies and disperse it in hot spots which they form when they stop in the Galactic halo. Such events are seen as cosmological gamma-ray bursts (GRBs) in other galaxies when their beamed radiation happens to point towards Earth. This source of CRs is located in the Galactic halo. It therefore explains the absence of the Greisen-Zatsepin-Kuz'min cutoff in the spectrum of the ultra-high energy CRs. The position in energy of the ``ankle'' in the CR energy spectrum is shown to arise in a natural way. Moreover, an origin of lower energy CRs in the Galactic halo naturally accounts for the high degree of isotropy of CRs around 100 TeV from airshower observations, and the small galactocentric gradient of low-energy CRs derived from gamma-ray observations.

A. Dar; R. Plaga

1999-02-09T23:59:59.000Z

499

Angular Correlations of the X-Ray Background and Clustering of Extragalactic X-Ray Sources  

E-Print Network (OSTI)

The information content of the autocorrelation function (ACF) of intensity fluctuations of the X-ray background (XRB) is analyzed. The tight upper limits set by ROSAT deep survey data on the ACF at arcmin scales imply strong constraints on clustering properties of X-ray sources at cosmological distances and on their contribution to the soft XRB. If quasars have a clustering radius r_0=12-20 Mpc (H_0=50), and their two point correlation function, is constant in comoving coordinates as indicated by optical data, they cannot make up more 40-50% of the soft XRB (the maximum contribution may reach 80% in the case of stable clustering, epsilon=0). Active Star-forming (ASF) galaxies clustered like normal galaxies, with r_0=10-12 Mpc can yield up to 20% or up to 40% of the soft XRB for epsilon=-1.2 or epsilon=0, respectively. The ACF on degree scales essentially reflects the clustering properties of local sources and is proportional to their volume emissivity. The upper limits on scales of a few degrees imply that hard X-ray selected AGNs have r_06 deg, if real, may be due to AGNs with r_0=20 Mpc; the contribution from clusters of galaxies with r_0~50 Mpc is a factor 2 lower.

L. Danese; L. Toffolatti; A. Franceschini; J. M. Martin-Mirones; G. De Zotti

1993-02-24T23:59:59.000Z

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A Path Forward for the Gulf Coast | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

A Path Forward for the Gulf Coast A Path Forward for the Gulf Coast A Path Forward for the Gulf Coast September 30, 2010 - 11:45am Addthis A Path Forward for the Gulf Coast Bill Valdez Bill Valdez Principal Deputy Director The Gulf Coast is a gate for commerce, producer of seafood, oil and natural gas, host to diverse ecosystems, home to millions and it's future is intertwined with the future of this Nation. Our country has made a promise to the people and small businesses of the Gulf Coast to restore their environment, economy and health, and continue a conversation with the fisherman, environmental workers, elected officials, health officials, scientists and Gulf residents on how to restore the Gulf. Those conversations and our promise to the Gulf are laid out in U.S. Navy Secretary Ray Mabus' report, which was released on Tuesday and presented