A5049559753- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Gyrotron and Vacuum Electronics Research
- Advanced X-ray Imaging Techniques
- Photocathodes and Microchannel Plates
- Particle Detector Development and Performance
- Superconducting Materials and Applications
- Laser Design and Applications
- Laser-Matter Interactions and Applications
- Radiation Detection and Scintillator Technologies
- Advanced Electron Microscopy Techniques and Applications
- Magnetic confinement fusion research
- Laser-Plasma Interactions and Diagnostics
- Advancements in Photolithography Techniques
- Electron and X-Ray Spectroscopy Techniques
- X-ray Spectroscopy and Fluorescence Analysis
- Terahertz technology and applications
- Distributed and Parallel Computing Systems
- Crystallography and Radiation Phenomena
- Radiation Therapy and Dosimetry
- Scientific Computing and Data Management
- Advanced Data Storage Technologies
- Muon and positron interactions and applications
- bioluminescence and chemiluminescence research
- Photonic and Optical Devices
Lawrence Berkeley National Laboratory
2013-2023
Argonne National Laboratory
2008
SLAC National Accelerator Laboratory
2007-2008
Brookhaven National Laboratory
2008
University of California, Berkeley
2008
Menlo School
2008
Fusion Academy
2008
Fusion (United States)
2008
Amyotrophic Lateral Sclerosis Association
2007
Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati
1995-2004
Bursts of coherent synchrotron radiation at far-infrared and millimeter wavelengths have been observed several storage rings. A microbunching instability has proposed as the source for bursts. However, mechanism yet to be elucidated. We provide first evidence that bursts are due a driven by emission in bunch. Observations made Advanced Light Source consistent with values predicted model. These results demonstrate new regime high energy sources could impact design future sources.
The Advanced Photoinjector Experiment (APEX) at the Lawrence Berkeley National Laboratory is dedicated to development of a high-brightness high-repetition rate (MHz-class) electron injector for x-ray free-electron laser (FEL) and other applications where high repetition rates brightness are simultaneously required. based on new concept rf gun utilizing normal-conducting (NC) cavity resonating in VHF band 186 MHz, operating continuous wave (cw) mode conjunction with quantum efficiency...
We present a model describing high power stable broadband coherent synchrotron radiation (CSR) in the terahertz frequency region an electron storage ring. The includes distortion of bunch shape from (SR), which enhances higher emission, and limits to emission due instability excited by SR wakefield. It gives quantitative explanation several features recent observations CSR at BESSY II also use this optimize performance source for emission.
We report on measurements and analysis of a field-emitted electron current in the very-high-frequency (VHF) gun, room temperature rf gun operating at high field continuous wave (CW) mode Lawrence Berkeley National Laboratory (LBNL). The VHF is core Advanced Photo-injector Experiment (APEX) LBNL, geared toward development an injector for driving next generation average power x-ray free lasers. High accelerating fields cathode are necessary high-brightness performance gun. When coupled with CW...
For the Linac Coherent Light Source II (LCLS-II) project at SLAC, a 1.3 GHz superconducting rf (SRF) linac is being constructed that will generate 4 GeV electron bunches high repetition rate to drive x-ray free lasers. The LCLS-II source, which comprises first three meters of injector, includes two normal-conducting, continuous-wave cavities: one-cell, 185.7 MHz gun and two-cell, buncher. It also load-lock system allows photocathodes be changed under vacuum. components in this beam-line...
We present a new method to generate steady and tunable, coherent, broadband terahertz radiation from relativistic electron beam modulated by femtosecond laser. have demonstrated this in the storage ring at Advanced Light Source. Interaction of an with laser pulse copropagating through wiggler modulates energies within short slice bunch about same duration pulse. The develops longitudinal density perturbation due dispersion trajectories, resulting hole emits pulses temporally spatially...
The very-high-frequency gun (VHF-Gun) is a new concept photo-injector developed and built at the Lawrence Berkeley National Laboratory (LBNL) for generating high-brightness electron beams capable of driving X-ray free lasers (FELs) MHz-class repetition rates. that purposely uses established mature radiofrequency mechanical technologies has demonstrated over last many years capability reliably operating in continuous wave mode design accelerating fields required vacuum performance. results...
We report on the performances of a Cs2Te photocathode under extreme conditions high peak time-dependent accelerating fields, continuous wave operations, and MHz pulse extraction with up to 0.3 mA average current. The measurements, performed in normal conducting cavity, show extended lifetime robustness, elucidate main mechanisms for cathode degradation, set required system vacuum performance compatibility operations power X-ray free electron laser user facility, opening doors next generation...
K-Cs-Sb bialkali antimonide photocathodes grown by a triple-element codeposition method have been found to excellent quantum efficiency (QE) and outstanding near-atomic surface smoothness employed in the VHF gun Advanced Photoinjector Experiment (APEX), however, their robustness terms of lifetime at elevated photocathode temperature has not yet investigated. In this paper, relationship between The origin significant QE degradation temperatures over $70\text{...
The generation of brilliant, stable, and broadband coherent synchrotron radiation (CSR) in electron storage rings depends strongly on ring rf system properties such as frequency gap voltage. We have observed intense at frequencies approaching the THz regime produced by MIT-Bates South Hall Ring, which employs a high-frequency $S$-band system. measured CSR spectral intensity enhancement with 2 mA stored current was up to 10 000 times above background for wave numbers near $3\text{ }\text{...
A high repetition rate, MHz-class, high-brightness electron source is a key element in future high-repetition-rate x-ray free laser-based light sources. The VHF-gun, novel low frequency radio-frequency gun, the Lawrence Berkeley National Laboratory (LBNL) response to that need. gun design based on normal conducting, single cell cavity resonating at 186 MHz VHF band and capable of continuous wave operation while still delivering accelerating fields cathode required for brightness performance....
By analyzing the pulse to intensity fluctuations of radiation emitted by a charge particle in incoherent part spectrum, it is possible extract information about spatial distribution beam. At Advanced Light Source Lawrence Berkeley National Laboratory, we have developed and successfully tested simple scheme based on this principle that allows for absolute measurement rms bunch length. A description method experimental results are presented.
We report the first observation of laser seeding storage-ring microbunching instability. Above a threshold bunch current, interaction beam and its radiation results in coherent instability, observed as series stochastic bursts synchrotron (CSR) at terahertz frequencies initiated by fluctuations density. have that this effect can be seeded imprinting an initial density modulation on means "slicing." In such situation, most CSR become synchronous with pulses modulating their average intensity...
The traditional process of designing and tuning the magnetic lattice a particle storage ring to produce certain desired properties is not straightforward. Often solutions are found through trial error it clear that close optimal. This can be very unsatisfying process. In this paper we take step back look at general stability limits lattice. We employ technique call GLASS (GLobal scan All Stable Settings) allows us rapidly find all possible stable modes then characterize their associated...
BIW08, the 13th edition of Beam Instrumentation Workshop (BIW), took place at Lake Tahoe, California, on May 4–7, 2008. It was jointly sponsored by three divisions Berkeley Lab: Accelerator and Fusion Research, Advanced Light Source (ALS), Engineering. BIW is a biannual international conference beam diagnostics instrumentation for accelerators probably most important in field together with its European counterpart, DIPAC, which alternates odd years.
Abstract Several recent reports have identified the scientific requirements for a future soft X-ray light source [Citation1, Citation2, Citation3, Citation4, Citation5], and high-repetition-rate free-electron laser (FEL) facility responsive to them is being studied at Lawrence Berkeley National Laboratory (LBNL) [Citation6]. The based on continuous-wave (CW) superconducting linear accelerator with beam supplied by high-brightness, photocathode electron gun operating in CW mode, an array of...
The past decade was characterized by an increasing scientific demand for extending towards higher repetition rates (MHz class and beyond) the performance of already operating lower rate accelerator-based instruments such as x-ray free electron lasers (FELs) ultrafast diffraction (UED) microscopy (UEM) instruments. Such a need stimulated worldwide spread vibrant R activity targeting development high-brightness sources capable at these challenging rates. Among different technologies pursued,...