A5044001020- Nuclear Physics and Applications
- Radiation Detection and Scintillator Technologies
- Nuclear reactor physics and engineering
- Laser-Plasma Interactions and Diagnostics
- Aerodynamics and Acoustics in Jet Flows
- Particle Dynamics in Fluid Flows
- Cold Fusion and Nuclear Reactions
- Fluid Dynamics and Turbulent Flows
- Magnetic confinement fusion research
- Nuclear Materials and Properties
- High-pressure geophysics and materials
- Scientific Measurement and Uncertainty Evaluation
- Advanced X-ray and CT Imaging
- Advanced Data Storage Technologies
- Particle Detector Development and Performance
- Advanced Radiotherapy Techniques
- Medical Imaging Techniques and Applications
- Nuclear and radioactivity studies
Los Alamos National Laboratory
2012-2023
Wayne State University
2003
Ames Research Center
1986
The dense plasma focus (DPF) has long been considered a compact source for pulsed neutrons and traditionally optimized the total neutron yield. In this paper, we describe efforts to optimize DPF short-pulse applications by introducing reentrant cathode at end of coaxial gun. resulting pulse widths are reduced an average 21±9% from traditional long-drift design. Pulse yields achieved deuterium-tritium fusion 2 MA 61.8±30.7 ns FWHM 1.84±0.49×1012 per shot. Simulations were conducted...
The joint LANL/LLNL nuclear imaging team has acquired the first gamma-ray images of inertial confinement fusion implosions at National Ignition Facility. image provides crucial information to help characterize inertially confined fuel and ablator assembly stagnation, that would be difficult acquire from neutron or x-ray observations. Gamma visualizes both gamma radiation emitted directly in deuterium–tritium (DT) reactions as well rays produced when DT neutrons scatter inelastically on...
Neutron diagnosed subcritical experiments (NDSEs) aim to measure the fission chain decay of test objects initiated by neutrons from an external source. The ultimate goal future NDSEs is make such measurements on dynamic as they are imploded. As a step toward that goal, we made three static assemblies containing highly enriched uranium. Specifically, measured die-off both gamma rays and neutrons, with nanosecond resolution over several hundred microseconds, relative emission time source in...
The dose calculation accuracy of a commercial pencil beam IMRT planning system is evaluated by comparison with Monte Carlo calculations and measurements in an anthropomorphic phantom. target volume the right lung mediastinum thus significant tissue inhomogeneities are present. code adaptation msnp were made TLD film. Both show very good agreement treatment except regions where high electron density low. In these shows doses up to 10% higher than average calculated for CTV 5% as compared...
A pulsed neutron source is used to interrogate a target, producing secondary gammas and neutrons. In order make good use of the relatively small number gamma rays that emerge from system after flash, our detector must be both efficient in converting detectable electronic signal reasonably large volume. Isotropic are emitted target. These signals converted light within chamber liquid scintillator. To provide adequate time-of-flight separation between signals, scintillator placed meters away...
We examine the effect of realistic pinhole geometries used in neutron imaging on size image produced plane. Using a simple inverted parabola shape for source, an MCNP simulation shows that area images are only very slightly changed by blurring. metric, A80, which is contains 80% neutrons, we find maximum 1.5% increase metric. In comparing `perfect' cylinder bore hole approximation with full stepped collimator tapered difference A80 0.8%. addition, little prediction compared to ray-tracing...
A new two-channel laser Doppler velocimeter developed for the Ames High Reynolds Channel No. II is described. Design features required satisfactory operation of optical system in channel environment are discussed. Fiber optics used to transmit megahertz signal photodetectors located outside pressure vessel, and provision made isolate from thermal strain effects. Computer-controlled scanning mirrors psoition beams flow. Techniques seed flow with 0.5-μ-diam polystyrene spheres avoiding...