J. Bundgaard
A5013849784- Nuclear Physics and Applications
- Nuclear reactor physics and engineering
- Radiation Detection and Scintillator Technologies
- Nuclear physics research studies
- Nuclear Materials and Properties
- Atomic and Subatomic Physics Research
- Magnetic confinement fusion research
- Particle Detector Development and Performance
- Laser-induced spectroscopy and plasma
- Augmented Reality Applications
- Advancements in PLL and VCO Technologies
- Superconducting and THz Device Technology
- Rare-earth and actinide compounds
- Engineering and Test Systems
- X-ray Spectroscopy and Fluorescence Analysis
- Semiconductor Lasers and Optical Devices
- Radioactivity and Radon Measurements
- Virtual Reality Applications and Impacts
- Laser-Plasma Interactions and Diagnostics
- Radioactive Decay and Measurement Techniques
- Radiation Therapy and Dosimetry
- Cold Fusion and Nuclear Reactions
Nevada National Security Site
2020-2024
Colorado School of Mines
2013-2022
University of Tennessee at Knoxville
2022
Nordic Laboratory for Luminescence Dating
1989
Joint European Torus
1988
By combining the time-of-flight or LIDAR principle with a Thomson backscatter diagnostic, spatial profiles of electron temperature and density are measured in magnetically confined fusion plasma. This technique was realized for first time on JET tokamak. A ruby laser (3-J pulse energy, 300-ps duration, 0.5-Hz repetition rate) together 700-MHz bandwidth detection registration system yields resolution about 12 cm. spectrometer six channels wavelength range 400–800 nm gives dynamic measurements...
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...
Neutron radiography is a technique uniquely suited to applications in nuclear diagnostics, non-destructive testing, and subcritical experiments. The spatial resolution of neutron radiographs degraded by optical blur the imaging system source size, where ideal point-like optimize point-spread function. A potential for dense plasma focus (DPF), coaxial Z-pinch that produces thermonuclear beam-target neutrons. To assess if size suitable radiography, was used measure 4 MA Sodium DPF at Nevada...
Isomeric states in the neutron-rich nuclei Zr111 [T1/2=0.10(7)μs], Nb113 [T1/2=0.7(4)μs], Mo115 [T1/2=46(3)μs] were first identified at Radioactive Ion Beam Factory (RIBF) of RIKEN by using in-flight fission and fragmentation a U238 beam an energy 345 MeV/u. This is brief report γ transitions de-exciting from isomeric half-lives measurements, which provides spectroscopy nuclear region prolate-to-oblate shape-phase transition around mass A ≈110.Received 22 October 2022Revised 28 November...
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...
The general properties needed in targets (sources) for high precision, accuracy measurements are reviewed. application of these principles to the problem developing Fission TPC is described. Longer term issues, such as availability actinide materials, improved knowledge energy losses and straggling stability during irradiation also discussed.
The electronics for the microchannel plate photomultiplier tubes used in LIDAR (Light Detection and Ranging) Thomson scattering diagnostic on JET tokamak are described. It is shown how gated with a very small coupling between gate signal output, ≊300 V transient pulses rise times of 230 ps clipped to safe levels ≊40 V.
The $^{239}$Pu(n,f)/$^{235}$U(n,f) cross-section ratio has been measured with the fission Time Projection Chamber (fissionTPC) from 100 keV to MeV. fissionTPC provides three-dimensional reconstruction of fission-fragment ionization profiles, allowing for a precise quantification measurement uncertainties. was performed at Los Alamos Neutron Science Center which pulsed white source neutrons. data are recommended be used as shape. A discussion status absolute normalization and comparisons ENDF...
Prototype zoom lenses should be designed with flexibility. One never knows what the future use of a prototype as-build lens will be. In prior design large-image-format used for proton radiography, extra back focal distance was constrained in to allow insertion lenses. These added can change magnification different camera system, having smaller image size. Three single commercial elements were mounted into variable-length housing barrel that attached using 3Dprinted flange. This new has been...