A5059283390- Particle accelerators and beam dynamics
- Particle Accelerators and Free-Electron Lasers
- Gyrotron and Vacuum Electronics Research
- Pulsed Power Technology Applications
- Superconducting Materials and Applications
- Photocathodes and Microchannel Plates
- Microwave Engineering and Waveguides
- Advanced X-ray Imaging Techniques
- Laser Design and Applications
- Laser-Plasma Interactions and Diagnostics
- Ionosphere and magnetosphere dynamics
- Particle Detector Development and Performance
- Magnetic confinement fusion research
- Photonic and Optical Devices
- Plasma Diagnostics and Applications
- Terahertz technology and applications
- Superconducting and THz Device Technology
- Acoustic Wave Resonator Technologies
- Solar and Space Plasma Dynamics
- Berry genetics and cultivation research
- Nuclear Physics and Applications
- Earthquake Detection and Analysis
- Electron and X-Ray Spectroscopy Techniques
- Laser-Matter Interactions and Applications
- Photonic Crystals and Applications
Los Alamos National Laboratory
2015-2024
Los Alamos Medical Center
1994-2021
Fermi National Accelerator Laboratory
2018
Thomas Jefferson National Accelerator Facility
2015
Los Alamos National Security (United States)
2002
Office of Scientific and Technical Information
1998
In the field of beam physics, two frontier topics have taken center stage due to their potential enable new approaches discovery in a wide swath science. These areas are: advanced, high gradient acceleration techniques, and x-ray free electron lasers (XFELs). Further, there is intense interest marriage these fields, with goal producing very compact XFEL. this context, recent advances radio-frequency cryogenic copper structure research opened door use surface electric fields between 250 500...
A sheet-beam traveling-wave amplifier has been proposed as a high-power generator of radio frequency (RF) from 95 to 300 GHz, using microfabricated RF slow-wave structure (Carlsten, 2002). The planar geometry microfabrication technologies matches well with the nearly sheet beam, and greater allowable beam current leads high-peak power, high-average wide bandwidths. Simulations nominal designs vane-loaded waveguide have indicated gains in excess 1 dB/mm, extraction efficiencies than 20% at...
Talman [Phys. Rev. Lett. 56, 1429 (1986)] has proposed a novel relativistic effect that occurs when charged particle beam is bent in the magnetic field from an external dipole. The consequence of this space-charge forces particles do not exhibit usual inverse-square energy dependence and some part them are, fact, independent energy. This led to speculation could introduce significant emittance growth for bending electron beam. Subsequently, it was shown effect's influence on beam's...
A mode analysis is presented for the case of a planar electron beam in ridged waveguide slow-wave structure. By matching boundary conditions between Fourier expansion ridges with space-harmonic region below ridges, dispersion relation traveling-wave interaction found. The numerically solved both and without beam. For nominal geometry, gains as high 30 dB/cm at 300 GHz are found 15 A, 155 keV
Energetic electrons can be trapped in Earth's magnetic field, forming the radiation belts (also known as Van Allen Belts). These electrons, which originate from solar wind or a high-altitude nuclear explosion (HANE), have potential to damage satellites low-Earth orbit (LEO). For example, 1962, U.S. detonated device at an altitude of about 400 km Starfish experiment. The resulting enhancement disabled several within few months and energetic remained for up years. In order address this...
This document provides detailed information on the status of Advanced and Novel Accelerators techniques describes steps that need to be envisaged for their implementation in future accelerators, particular high energy physics applications. It complements overview prepared update European Strategy particle physics, a description field. The scientific priorities community are described each technique acceleration able achieve accelerating gradient GeV~range or above. ALEGRO working group...
After compressing electron bunches with a half-meter long, four-dipole chicane at 8 MeV, we have measured full width half maximum (FWHM) bunch lengths of less than 1 ps for charges from 0.1 to 1.1 nC. The uncompressed FWHM varied 10 20 ps, and achieved compression ratios in excess 40 peak currents greater kA. Bunch low were using transversely deflecting rf cavity; high inferred the energy spread induced beam by its longitudinal space-charge force as it drifted end compressor spectrometer.
Currently ongoing at Los Alamos National Laboratory is a program to develop high-power, planar 100--300 GHz traveling-wave tubes. A necessary part of this effort sheet electron beam source. Previously, we have described novel asymmetric solenoid lens concept for transforming the circular from high-perveance gun configuration. The standard electromagnetic with elliptical, instead circular, pole apertures. elliptical openings result in focusing, which turn forms an suitable our structures....
Dielectric materials are foundational to our modern-day communications, defense, and commerce needs. Although dielectric breakdown is a primary cause of failure these systems, we do not fully understand this process. We analyzed the channel propagation dynamics two distinct types electrical trees. One type trees has been formally classified. observed speed tree exceed 10 million meters per second. These results identify substantial gaps in understanding breakdown, filling paramount design...
The Dual-Axis Radiographic Hydrodynamics Test (DARHT) facility will use two perpendicular electron linear induction accelerators to produce intense, bremsstrahlung X-ray pulses for flash radiography. We intend measurements containing 3D information with sub-millimeter spatial of the interior features very dense explosively driven objects. be completed in phases first operational by June 1999 utilizing a single-pulse, 19.8-MeV, 2 4-kA, 60-ns accelerator (activated March 1999), high-resolution...
Recent investigations of RF copper structures operated at cryogenic temperatures performed by a SLAC-UCLA collaboration have shown dramatic increase in the maximum surface electric field, to 500 MV/m. We examine use these fields enable very high field photoinjectors that can attain over an order magnitude peak electron beam brightness. present dynamics studies relevant X-ray FEL injectors, using start-to-end simulations show brightness and low emittance this source enables operation compact...
The 1970s and 1980s were heydays for using active electron beam experiments to probe some of the fundamental physical processes that occur throughout heliosphere in astrophysical contexts. Electron used study spacecraft charging spacecraft-plasma coupling; beam-plasma interaction physics; magnetic bounce drift auroral wave generation; military applications. While these enormously successful, they also limited by technologies available at time. New advances space instrumentation, data...
The authors report some initial measurements of electron beam properties from the new photoinjector installed as front end on Los Alamos free-electron laser (FEL). FEL is being rebuilt with photoinjector, added acceleration to 40 MeV, diagnostics, and a line designed minimize emittance growth. measured spatial temporal at energies about 15 MeV function several parameters results have been compared simulations. operational characteristics important elements system theoretical comparisons are...
Two-plane focusing of sheet electron beams will be an essential technology for emerging class high-power, 100 to 300 GHz rf sources [Carlsten et al., IEEE Trans. Plasma Sci. 33, 85 (2005)]. In these devices, the beam has a unique asymmetry in which transport is emittance dominated sheet's thin dimension and space-charge wide dimension. Previous work studied stability emittance-dominated regime both wiggler periodic permanent magnet (PPM) configurations with single-plane focusing, found that...
The flat-beam transform (FBT) for round symmetric beams can be extended using the concept of eigenemittances. By tailoring initial beam conditions at cathode, including adding arbitrary correlations between any two dimensions, this extension used to provide greater freedom in controlling beam's final emittances. In principle, technique generate extraordinarily transversely bright electron beams. Examples are provided where an equivalent FBT is established horizontal and longitudinal dimensions.
The transport of planar electron beams is a topic increasing interest for applications to high-power, high-frequency microwave devices. This paper describes two- and three-dimensional simulations electron-beam in notched wiggler magnet array. calculations include self-consistent effects beam-generated fields. simple configuration can provide vertical horizontal confinement high-perveance sheet with small transverse dimensions. feasibility address beam system drive 95-GHz traveling-wave tube...
A sheet-beam traveling-wave amplifier has been proposed as a high-power generator of rf from 95 to 300 GHz, using microfabricated slow-wave structure [Carlsten et al., IEEE Trans. Plasma Sci. 33, 85 (2005)], for emerging radar and communications applications. The planar geometry microfabrication technologies matches well with the nearly sheet beam, greater allowable beam current leads high-peak power, high-average wide bandwidths. Simulations nominal designs vane-loaded waveguide have...
A general architecture of an emittance exchanger (EEX) is considered, where the horizontal and longitudinal phase spaces are exchanged. family designs described which can lead to extremely short final lengths, even subfemtosecond. Using higher-order particle simulations, a preferred configuration found, has better compression capability less growth than standard EEX design at high beam energy. An alternative also found eliminates any energy-phase coupling. Features using significantly...
In this paper, we examine intense space-charge beam physics that is relevant to bunching and extraction in a mildly relativistic klystron amplifier, give numerical examples for 5 kA, 500 keV electron 1.3 GHz structure. Much of the peculiar these types devices results from partitioning energy into kinetic potential parts. Both tenuous-nonrelativistic intense-relativistic beams produce effects different nature those produced by intense, because requirements are either negligible or fixed....
This paper describes the experimental development of a long pulse high current relativistic klystron amplifier (RKA). The desired performance parameters are 1 GW output power and /spl mu/s length with an operating frequency 1.3 GHz. Peak powers approaching 500 MW have been achieved in pulses nominal baseline-to-baseline duration. half width is 0.5 mu/s. These contain energy about 160 J. RF rises linearly concert beam pulse, terminates abruptly just before highest part pulsed voltage curve...