A5024460816- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Gyrotron and Vacuum Electronics Research
- Superconducting Materials and Applications
- Photonic and Optical Devices
- Photocathodes and Microchannel Plates
- Advanced X-ray Imaging Techniques
- Physics of Superconductivity and Magnetism
- Graphite, nuclear technology, radiation studies
- Laser Design and Applications
- Molten salt chemistry and electrochemical processes
- Particle Detector Development and Performance
- Advancements in Photolithography Techniques
- Magnetic confinement fusion research
- Nuclear Physics and Applications
- Electron and X-Ray Spectroscopy Techniques
- Photonic Crystals and Applications
- Quantum and Classical Electrodynamics
- Spacecraft and Cryogenic Technologies
- Quantum Information and Cryptography
- Acoustic Wave Resonator Technologies
- Magnetic properties of thin films
- Nuclear reactor physics and engineering
- Radiation Therapy and Dosimetry
- Microwave Engineering and Waveguides
Niowave (United States)
2011-2022
Los Alamos National Laboratory
2012-2017
Massachusetts Institute of Technology
2016
Brookhaven National Laboratory
2014
Deutsches Elektronen-Synchrotron DESY
2010
Vanderbilt University
2003-2007
German Institute for Adult Education
2007
The photoinjector test facility at DESY, Zeuthen site (PITZ), was built to develop and optimize photoelectron sources for superconducting linacs high-brilliance, short-wavelength free-electron laser (FEL) applications like the in Hamburg (FLASH) European x-ray (XFEL). In this paper, detailed characterization of two laser-driven rf guns with different operating conditions is described. One experimental optimization beam parameters performed an accelerating gradient about $43\text{ }\text{...
Continuous-wave photoinjectors operating at high accelerating gradients promise to revolutionize many areas of science and applications. They can establish the basis for a new generation monochromatic x-ray free electron lasers, high-brightness hadron beams, or microchip production. In this Letter we report on record-performing superconducting rf gun with ${\mathrm{CsK}}_{2}\mathrm{Sb}$ photocathode. The is generating charge bunches (up $10\text{ }\text{ }\mathrm{nC}/\text{bunch}$) low...
It has previously been shown that the electron beam in a Smith-Purcell free-electron laser interacts with synchronous evanescent wave. At high energy, group velocity of this wave is positive and device operates on convective instability, manner traveling-wave tube. For operation as an oscillator, gain must exceed losses external feedback system. low negative absolute like backward-wave no required. oscillation to occur, current so-called start current. intermediate called Bragg condition,...
Smith-Purcell (SP) radiation is emitted when an electron passes close to the surface of a metallic grating. The becomes coherent (fluence proportional square number electrons) electrons are in bunches whose dimensions smaller than wavelength radiation. This has been observed experiments which prebunched by rf linac. enhancement spectral intensity accompanied large changes angular and distribution appear periodic bunches. called superradiance. Recently, superradiant SP from so-called...
Superconducting radio-frequency electron guns are viewed by many as the preferred technology for generating high-quality, high-current beams needed future high power free-electron lasers and energy recovery linacs. All previous of this type have employed elliptical cavities, but there potential advantages associated with other geometries. Here we describe design, commissioning, initial results from a superconducting gun employing quarter-wave resonator configuration, first such device to be...
We have included the effects of losses in grating surface and reflections at ends theory Smith–Purcell free-electron lasers. Computations show that typically increase start current by about 10%. The complex reflection coefficient for evanescent wave is computed using numerical simulations, found to a magnitude on order 30%. This increases or decreases 10%, depending phase round-trip reflection.
We report the results of recent high power testing superconducting radio frequency photonic band gap (PBG) accelerator cells. Tests two single-cell 2.1 GHz cavities were performed at both 4 and 2 K. An accelerating gradient $15\text{ }\text{ }\mathrm{MV}/\mathrm{m}$ an unloaded quality factor ${Q}_{0}$ $4\ifmmode\times\else\texttimes\fi{}{10}^{9}$ achieved. It has been long realized that PBG structures have great potential in reducing long-range wakefields accelerators. A structure confines...
The Coherent Electron Cooling Proof of Principle (CeC PoP) system is being installed in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. It will demonstrate ability relativistic electrons to cool a single bunch heavy ions RHIC. This technique may increase beam luminosity by as much tenfold. Within scope this experiment, 112 MHz 2 MeV Superconducting Radio Frequency (SRF) electron gun coupled with cathode stalk mechanism, two normal conducting 500 single-cell...
Crab crossing is essential for high-luminosity colliders. The Large Hadron Collider (HL-LHC) will equip one of its interaction points (IP1) with double-quarter wave (DQW) crab cavities. A DQW cavity a new generation deflecting rf cavities that stands out compactness and broad frequency separation between fundamental first high-order modes. kick provided by mode. Each HL-LHC shall provide nominal voltage 3.4 MV, although up to 5.0 MV may be required. proof-of-principle (POP) was limited...
High-bunch-charge photoemission electron-sources operating in a continuous wave (CW) mode are required for many advanced applications of particle accelerators, such as electron coolers hadron beams, electron-ion colliders, and free-electron lasers. Superconducting RF (SRF) has several advantages over other electron-gun technologies CW it offers higher acceleration rate potentially can generate bunch charges average beam currents. A 112 MHz SRF photoinjector (gun) was developed at Brookhaven...
At the tips of sharp needles, surface electric field is enhanced by many orders magnitude. This intensifies thermionic emission and photoemission electrons through Schottky effect, reduces effect space charge. The increased current density improves brightness electron sources In addition, at very high fields (>10 9 V/m ), photo-field produce density. Arrays needles can be used to achieve total current.
We report results from recent 2.1 GHz superconducting radio frequency (SRF) photonic band gap (PBG) resonator experiments at Los Alamos. Two PBG cells with elliptical rods were fabricated and tested high power in a liquid helium bath the temperatures of 4 K below 2 K. The described SRF designed particular emphasis on changing shape to reduce peak surface magnetic fields same time preserve its effectiveness damping higher-order-modes. cavities have great potential for long-range wakefields...
High-gradient CW photo-injectors operating at high accelerating gradients promise to revolutionize many sciences and applications. They can establish the basis for super-bright monochromatic X-ray free-electron lasers, hadron beams, nuclear- waste transmutation or a new generation of microchip production. In this letter we report on our operation superconducting RF electron gun with record-high gradient CsK2Sb photocathode (i.e. ~ 20 MV/m) generating bunch charge (i.e., 3 nC). We briefly...