A5058243803- Nuclear Physics and Applications
- Nuclear reactor physics and engineering
- Nuclear physics research studies
- Radiation Detection and Scintillator Technologies
- Nuclear Materials and Properties
- Pulsed Power Technology Applications
- Gyrotron and Vacuum Electronics Research
- Electrostatic Discharge in Electronics
- Laser-Plasma Interactions and Diagnostics
- Particle Detector Development and Performance
- Luminescence Properties of Advanced Materials
- Radio Wave Propagation Studies
- Magnetic confinement fusion research
- Political and Economic history of UK and US
- Mechatronics Education and Applications
- High-Energy Particle Collisions Research
- Space Technology and Applications
- Digital Holography and Microscopy
- X-ray Spectroscopy and Fluorescence Analysis
- Superconducting Materials and Applications
- Antenna Design and Optimization
- Radiology practices and education
- Combustion and Detonation Processes
- Advanced Electron Microscopy Techniques and Applications
- Ionosphere and magnetosphere dynamics
Los Alamos National Laboratory
2014-2025
United States Naval Research Laboratory
2018-2022
Colorado School of Mines
2013-2018
We measure the average spin of 144Ba, a common fragment produced in 252Cf(sf), as function total kinetic energy (TKE). combine twin Frisch-gridded ionization chamber with world-class 𝛾-ray spectrometer that was designed to high-multiplicity events, Gammasphere. The chamber, loaded 252Cf(sf) source, provides fission trigger, TKE fragments, approximate masses, and polar angle axis. Gammasphere yield, identification through tagging decay 𝛾 rays, feeding rotational bands fragments. determine...
The fragment mass and kinetic energy in neutron-induced fission of $^{238}\mathrm{U}$ has been measured for incident energies from 1 to 30 MeV at the Los Alamos Neutron Science Center. change distributions over this range were studied, transition highly asymmetric more symmetric is observed. A decrease average total $(\overline{\mathrm{TKE}})$ with increasing excitation observed, consistent previous experimental work. Additional structure multichance thresholds present...
The average total kinetic energy $(\overline{TKE})$ in $^{239}\mathrm{Pu}(n,f)$ has been measured for incident neutron energies between 0.5 and 50 MeV. experiment was performed at the Los Alamos Neutron Science Center (LANSCE) using time-of-flight technique, of fission fragments post-neutron emission a double Frisch-gridded ionization chamber. This represents first experimental study dependence $\overline{TKE}$ $^{239}\mathrm{Pu}$ above 6
The covariance committee of CSEWG (Cross Section Evaluation Working Group) established templates expected measurement uncertainties for neutron-induced total, (n, γ ), charged-particle, and (n,xn) reaction cross sections as well prompt fission neutron spectra, average total multiplicities, yields. Templates provide a list what uncertainty sources are each type observable, suggest typical ranges these correlations based on survey experimental data, associated literature, feedback from...
A cloud of very fast, O (km/s), and fine, (µm), particles may be ejected when a strong shock impacts possibly melts the free surface solid metal. To quantify these dynamics, this work develops an ultraviolet, long-working distance, two-pulse Digital Holographic Microscopy (DHM) configuration is first to replace film recording with digital sensors for challenging application. proposed multi-iteration DHM processing algorithm demonstrated automated measures sizes, velocities, three-dimensional...
Fission fragment angular distributions can provide an important constraint on fission theory, improving predictive codes, and are a prerequisite for precise ratio cross section measurement. Available anisotropy data is sparse, especially at neutron energies above 5 MeV. For the first time, three-dimensional tracking detector employed to study emission angles direct measurement of anisotropy. The Neutron Induced Fragment Tracking Experiment (NIFFTE) collaboration has deployed time projection...
The normalized $^{238}$U(n,f)/$^{235}$U(n,f) cross section ratio has been measured using the NIFFTE fission Time Projection Chamber from reaction threshold to $30$~MeV. fissionTPC is a two-volume MICROMEGAS time projection chamber that allows for full three-dimensional reconstruction of fission-fragment ionization profiles neutron-induced fission. measurement was performed at Los Alamos Neutron Science Center, where neutron energy determined time-of-flight. reported here first made with...
The Neutron Induced Fission Fragment Tracking Experiment (NIFFTE) collaboration has performed measurements with a fission time projection chamber (fissionTPC) to study the process by reconstructing full three-dimensional tracks of fragments and other ionizing radiation. amount linear momentum imparted fissioning nucleus incident neutron can be inferred measuring opening angle between fragments. Using this measured momentum, fragment angular distributions converted center-of-mass frame for...
Different aspects of the nuclear fission process have been studied at Los Alamos Neutron Science Center (LANSCE) using various instruments and experimental techniques. Properties fragments emitted in investigated Frisch-grid ionization chambers, a Time Projection Chamber (TPC), SPIDER instrument which employs 2v-2E method. These techniques used to determine product mass yields, energy dependent total kinetic (TKE) release, anisotropy neutron-induced U-235, U-238 Pu-239.
The average Total Kinetic Energy (TKE) release and fission-fragment yields in neutron-induced fission of 235U 238U was measured using a Frisch-gridded ionization chamber. These observables are important nuclear data quantites that relevant to applications for informing the next generation models. measurements were performed Los Alamos Neutron Science Center cover En = 200 keV – 30 MeV. double-energy (2E) method used determine two methods correcting prompt-neutron emission explored. results...
The Aerogel Cherenkov Detector for Cygnus (ACD/C) is a time-dependent, x-ray spectral detector that uses SiO2 aerogels spanning an index of refraction (n = 1.02-1.07) corresponding to 1.1-2.3 MeV energy threshold. ACD/C was developed pulsed power sources like located at the Nevada National Site and Mercury Naval Research Laboratory (NRL). Aerogels sit between measurement capabilities gas (>2 MeV) solids such as fused silica (>0.3 MeV). aluminum converter Compton scatter incoming x-rays...
Nuclear data related to the fission process are needed for a wide variety of research areas, including fundamental science, nuclear energy and non-proliferation. While some relevant have been measured required accuracies there still many aspects that need further investigation. One such aspect is how Total Kinetic Energy (TKE), fragment yields, angular distributions other observables depend on excitation fissioning system. Another question correlation between mass, charge fragments. At Los...
An experimental campaign was recently completed at the U.S. Naval Research Laboratory's Mercury pulsed-power facility, where feasibility of using a 5 MV inductive voltage adder (IVA) as pulsed photoneutron source studied. In these experiments, large-area bremsstrahlung diode fielded on accelerator, producing an intense, x-ray beam, which generated photoneutrons when striking appropriate target. This paper reports simulations that were performed to study production electron beam in diode, and...
The Neutron Induced Fission Fragment Tracking Experiment (NIFFTE) is a double-sided Time Projection Chamber (TPC) with micromegas readout designed to measure the energy-dependent neutron-induced fission cross sections of major and minor actinides unprecedented accuracy. NIFFTE project addresses challenge minimizing sources systematic uncertainties from previous chamber measurements such as: target beam non-uniformities, misidentification alpha light charged particles as fragments, inherent...