A5036317267- Particle accelerators and beam dynamics
- Gyrotron and Vacuum Electronics Research
- Diamond and Carbon-based Materials Research
- Particle Accelerators and Free-Electron Lasers
- Metal and Thin Film Mechanics
- Ion-surface interactions and analysis
- Pulsed Power Technology Applications
- Semiconductor materials and devices
- Plasma Diagnostics and Applications
- Electromagnetic Compatibility and Measurements
- Magnetic Properties and Applications
- Microwave and Dielectric Measurement Techniques
- Electrohydrodynamics and Fluid Dynamics
- Vacuum and Plasma Arcs
- Non-Destructive Testing Techniques
- Radioactive element chemistry and processing
- Nuclear Materials and Properties
- Microwave Engineering and Waveguides
- Antenna Design and Analysis
- Antenna Design and Optimization
- Radiation Detection and Scintillator Technologies
- Nuclear materials and radiation effects
- Magnetic Field Sensors Techniques
- GaN-based semiconductor devices and materials
- Photocathodes and Microchannel Plates
Michigan State University
2019-2023
Los Alamos National Laboratory
2021-2023
SLAC National Accelerator Laboratory
2022
Stanford University
2022
Wright State University
2018
State Council of Higher Education for Virginia
2018
We report the high gradient testing results of two single-cell off-axis coupled standing wave accelerating structures. Two brazed structures with same geometry were tested: one made pure copper (Cu) and a copper–silver (CuAg) alloy silver concentration 0.08%. A peak surface electric field 450 MV/m was achieved in CuAg structure for klystron input power 14.5 MW 1 μs pulse length, which 25% higher than Cu structure. The superb performance because major optimizations cavity's geometry: (1)...
Planar nitrogen-incorporated ultrananocrystalline diamond [(N)UNCD] has emerged as a unique field emission source attractive for accelerator applications because of its capability to generate high charge beam and handle moderate vacuum conditions. Most importantly, (N)UNCD sources are simple produce: Conventional aspect ratio isolated emitters not required be formed on the surface, actual emitter surface roughness is order only 10--100 nm. A careful reliability assessment before it may find...
The design and optimization of laser-Compton x-ray systems based on compact distributed charge accelerator structures can enable micron-scale imaging disease the concomitant production beams Very High Energy Electrons (VHEEs) capable producing FLASH-relevant dose rates. physics scattering ensures that scattered x-rays follow exactly trajectory incident electrons, thus providing a route to image-guided, VHEE FLASH radiotherapy. keys architecture both VHEEs are use X-band RF which have been...
Diamond field emitter array emission cathodes (DFEA FECs) are attractive for the next generation of injectors due to their ability produce transversely shaped beams without need complex masking or laser schemes. However, reliability this cathode technology remains a challenging issue as principal mechanisms guiding and allowing output beam shaping remained poorly understood. This paper reports results testing two DFEA FECs with same pattern tip geometry. Although both were able sustain...
High current bright sources are needed to power the next generation of compact rf and microwave systems. A major requirement is that such a source could be sustainably operated at high frequencies, well above 1 GHz, gradients, 100 MV/m. Field emission offer simplicity scalability in frequency era injector design, but output cycle charge gradient operation remain great largely unaddressed challenge. Here, field cathode based on ultra-nano-crystalline diamond or UNCD, an efficient planar...
This work presents an open-source code, FEgen, that generates initial field emission distributions based on the time-dependent Fowler–Nordheim equation. Current in-demand and beam tracking software—such as ASTRA, IMPACT-T, GPT—do not contain native distribution generator functions suitable for emitted electron phase space analysis. The intuitive graphical user interface of FEgen input files shown to be fully compatible with both ASTRA GPT. Here, detailed application examples demonstrating a...
FEbeam is an all-in-one field emission data processing interface with the capability to analyze cathode performance in rf injector by extracting enhancement factor, local field, and effective area from Fowler–Nordheim equations. It also has of beam imaging micrographs using its sister software, FEpic. The current version was designed for Argonne Cathode Test-stand Wakefield Accelerator facility switch yard. With slight modifications, could work many injectors. This software open-source can...
High peak power, tunable, narrowband terahertz emitters are becoming sought after given their portability, efficiency, and ability to be deployed in the field for industrial, medical, military applications. The use of accelerator systems producing THz frequencies via Cherenkov radiation, generated by passing an electron beam through a slow-wave wakefield structure, is promising method meet future requirements. To date, efforts have been dedicated analysis design sources utilizing laser...
The effective Debye temperature ( ) of the surface a single crystal U 0.71 Th 0.79 O 2 alloy prepared by hydrothermal synthesis is obtained from temperature‐dependent X‐ray photoemission in range 300–623 K. average determined to be 217 ± 24 fluorescence (XRF) spectroscopy confirms crystal's composition as . Photoemission reveals both thorium and uranium 4f states, which includes 4+ oxidation states. alloy, measured via photoemission, lower than urania or thoria literature values, indicating...
FEgen is a comprehensive user interface designed to create initial particle distributions for field emission sources operated in rf guns (additional capability exists dc pulsed power systems).
Field emission cathodes (FECs) are attractive for the next generation of injectors due to their ability provide high current density bright beams with low intrinsic emittance. One application FECs worthy special attention is transversely shaped electron emittance exchange that translates a transverse beam pattern into longitudinal pattern. can be fabricated in desired and produce without need complex masking or laser schemes. However, reliable consistent production affected by material...
We report the results of high gradient testing two single cell off axis coupled standing wave accelerating structures. Two brazed side structures with same geometry were tested one made pure copper Cu and a silver CuAg alloy concentration 0.08 percent. A peak surface electric field 450 MV per m was achieved in structure for klystron input power 14.5 MW 1 mirco s pulse length which 25 percent higher than structure. The superb performance because major optimizations cavity shunt impedance...
This paper describes the current status of newly commissioned C-band Engineering Test Facility in New Mexico (CERF-NM) at Los Alamos National Laboratory (LANL). At LANL, we designed and assembled a new test stand with goal to conduct high gradient breakdown studies frequencies (5.712 GHz). The is powered by 50 MW, 5.712 GHz Canon klystron. It capable conditioning single cell accelerating cavities for operation surface electric fields excess 300 MV/m. first two have just undergone power...