SCIENTIFIC AND TECHNICAL AEROSPACE REPORTS

A Biweekly Publication of the National Aeronautics and Space Administration
VOLUME 44, ISSUE 12 - JUNE 20, 2006

73 NUCLEAR PHYSICS
Includes nuclear particles; and reactor theory.

For space radiation see 93 Space Radiation.

For atomic and molecular physics see 72 Atomic and Molecular Physics.

For elementary particle physics see 77 Physics of Elementary Particles and Fields.

For nuclear astrophysics see 90 Astrophysics.

20060014134 Texas Univ. at Dallas, Richardson, TX USA

Renewal of Research on Triggering Nuclear Spin Isomers

Collins, Carl B; Nov 30, 2005; 16 pp.; In English Contract(s)/Grant(s): F49620-02-1-0141 Report No.(s): AD-A441411; No Copyright; ONLINE: http://hdl.handle.net/100.2/ADA441411; Avail.: CASI: A03, Hardcopy

Nuclear spin isomers store electromagnetic energy at densities reaching 1.3 GJ/g for shelf lives approaching centuries. The best combination of shelf life and energy storage is found in Hf-178. It has been shown to release its stored energy when triggered by x-ray flashes at modest power levels. In this work trigger pulses were derived from tunable, monochromatic x-rays produced by synchrotron radiation sources. It was proven that the triggering was initiated by photoionization of an electron from the L-shell surrounding the isomeric nucleus. A fraction of 0.16% of those photoionizing events led to triggering of the release of the energy stored by the Hf-178 nuclear spin isomer. Confidence in these positive experimental results reached 92 sigma which is equivalent to 1,824 nines of certainty. DTIC

Energy Storage; Isomers; Nuclear Spin

20060014736 Massachusetts Inst. of Tech., Cambridge, MA USA

Colloid Thrusters, Physics, Fabrication and Performance

Martinez-Sanchez, Manuel; Akinwande, Akintunde I; Nov 17, 2005; 14 pp.; In English Contract(s)/Grant(s): F49620-01-1-0398 Report No.(s): AD-A442444; No Copyright; ONLINE: http://hdl.handle.net/100.2/ADA442444; Avail.: CASI: A03, Hardcopy

This document summarizes the results of 3 and 1/2 years of work by our team on the basic physics and technology required for the development of Colloid Thrusters (also called more recently Electrospray Thrusters). The research covered the basic physics of operation in the mixed ion-droplet mode, later extended to the newly discovered pure ionic mode, the microfabrication in Silicon of two types of arrays of colloid or electrospray emitters, and the development of a quantitative theory for the colloidal regime (no ions). This Executive Summary describes briefly the various achievements, with reference to our interim Reports and to our publications. Special emphasis is placed on the results that were obtained during the one-year extension (2004), which were not covered in our interim reports. The Theses, published papers and Conference papers for 2004 are enclosed in a companion CD disk; earlier Theses and publications were similarly attached to previous Reports. DTIC

Colloids; Fabrication; Physics; Propulsion System Configurations; Propulsion System Performance

20060015187 Johns Hopkins Univ., Baltimore, MD USA

Endourethral MRI Guidance for Prostatic RF Ablation

Atalar, Ergin; Jun 2005; 120 pp.; In English Contract(s)/Grant(s): DAMD17-01-1-0064 Report No.(s): AD-A443051; No Copyright; ONLINE: http://hdl.handle.net/100.2/ADA443051; Avail.: CASI: A06, Hardcopy

Prostate cancer constitutes a major health problem. Although the medical techniques currently in use to diagnose prostate cancer are successful, the methods to stage the cancer and visualize the invasion and spread of the cancer are inadequate. MRI is known to be the best method for staging but it does not offer image resolution that is acceptable, especially for detecting disease in the anterior prostate. In the first year of the project, we have developed a phased array coil setup that enabled us to image the prostate with a 160-micron image resolution. The second year, we developed a mechanical setup that enabled placement of the needles in the prostate with 1mm accuracy. Results from both of these endeavors have been published in high-impact journals. We have also developed methods for imaging temperature changes in the prostate with high accuracy. Most of the goals of this project have been achieved. DTIC

Ablation; Cancer; Imaging Techniques; Magnetic Resonance; Prostate Gland; Radio Frequencies; Resolution

20060015592National War Coll., Washington, DC USA

U.S. 'Buyout' of North Korea's Nuclear Weapons Effort: A Blueprint or a Mistake?

Stickford, Thomas E; Jan 1995; 15 pp.; In English Report No.(s): AD-A441051; NDU/NWC-95-E-65; No Copyright; ONLINE: http://hdl.handle.net/100.2/ADA441051; Avail.: CASI: A03, Hardcopy

'North Korea Pact Contains U.S. Concessions -- Agreement Would Allow Presence of Key Plutonium-Making Facilities for Years.' Such were the headlines on the front page of The Washington Post on October 19, 1994. These headlines and the accompanying article reflected negatively on an agreement concerning North Korea's nuclear program. The need to limit North Korean nuclear capability is an important issue on many levels. Whether or not North Korea either has or is close to having nuclear weapons has grave repercussions for regional stability in terms of the immediate threat to South Korea and the USA. A nuclear armed North Korea would also upset the current regional balance in East Asia sufficiently to cause Japan, prominent among others, to rethink its security needs. Additionally, the temptation for economically strapped North Korea to gain hard currency through the sale of nuclear materials or weapons to currently non-nuclear states is all too real, with global consequences. While it appears obvious that denying a nuclear weapons capability to North Korea is in the USA' best interests, it is not obvious that this agreement will accomplish that feat.

Over and above North Korea's capabilities, the recent agreement has implications of its own, the most notable, in the author's view, being that it may set a precedent for future nonproliferation efforts. Has the USA sent a signal to other states with the potential to make nuclear weapons that they can bargain for great gain before agreeing to internationally accepted limits, controls, and inspections? In this paper, the author looks at this watershed accord between the USA and the Democratic People's Republic of Korea (DPRK); its history, its substance, and the controversy surrounding its implications. He also sets forth some thoughts on the accord's ramifications for U.S. nonproliferation policy. DTIC

Agreements; Blueprints; Fissionable Materials; Foreign Policy; North Korea; Nuclear Weapons; United States

20060015762 Naval Postgraduate School, Monterey, CA USA

Radiation Testing of the Configurable Fault Tolerant Processor (CFTP) for Space-Based Applications

Coudeyras, James C; Dec 2005; 165 pp.; In English; Original contains color illustrations Report No.(s): AD-A443431; No Copyright; ONLINE: http://hdl.handle.net/100.2/ADA443431; Avail.: Defense Technical Information Center (DTIC)

Field Programmable Gate Arrays (FPGAs) provide a reconfigurable asset in the design of space computing. Hardware configurations are stored in FPGA memory elements, which are susceptible to Single Event Upsets (SEUs). What is the best way to detect and mitigate SEUs and correct them before they become functional errors? The Configurable Fault Tolerant Processor (CFTP) consists of a controller FPGA (X1) controlling an experiment FPGA (X2), which can be used to test different fault-mitigation techniques. This focus of this thesis was to develop and execute a radiation test plan to evaluate different experiments in a proton radiation beam at Crocker Nuclear Laboratory, Davis, CA. A shift register was designed to determine a proton flux conducive to SEU observation. The shift register was also modified to create two additional configurations, implemented with the memory elements of the Look-Up Table and Flip-flops within an FPGA Configurable Logic Block. The data collected from this program was then analyzed for SEU rates and fault susceptibility. This data was extrapolated using a radiation environment model to predict the on-orbit SEU-rate for CFTP in the NPSAT1 orbit of 560 km, 35.4 degrees inclination, as well as Virtex II FPGAs and at 1000 and 1500 km altitudes. DTIC

Fault Tolerance

Source: NASA