A5103114111- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Gyrotron and Vacuum Electronics Research
- Photocathodes and Microchannel Plates
- Superconducting Materials and Applications
- Advanced X-ray Imaging Techniques
- Particle Detector Development and Performance
- Laser-Plasma Interactions and Diagnostics
- Pulsed Power Technology Applications
- Nuclear Physics and Applications
- Ferroelectric and Piezoelectric Materials
- Radio Frequency Integrated Circuit Design
- Microwave Engineering and Waveguides
- Advanced ceramic materials synthesis
- Scientific Computing and Data Management
- Laser Design and Applications
- Microwave Dielectric Ceramics Synthesis
- HIV/AIDS Impact and Responses
- Research Data Management Practices
- Laser-Matter Interactions and Applications
- Energetic Materials and Combustion
- Electromagnetic Launch and Propulsion Technology
- Photonic and Optical Devices
- Plasma Diagnostics and Applications
- Agricultural Innovations and Practices
Los Alamos National Laboratory
2005-2024
Los Alamos Medical Center
2012
Los Alamos National Security (United States)
2002
This paper presents evaluations of government policies by poor residents Colombo who were active participants in initiatives to improve housing and basic services. Their testimony tells the radical break from conventional, top-down approaches within government’s Million Houses Programme during late 1980s early 1990s. Community development councils a participatory methodology known as community action planning meant that leaders worked with officers identify problems, set priorities develop...
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...
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.
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.
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...
The generation and transport of planar electron beams is a topic increasing interest for applications to high-power, high-frequency microwave devices. This paper describes the use solenoid lenses with elliptical pole apertures transform circular high-perveance beam configuration. resulting transformation system has short axial length easily fabricated. Furthermore, approach allows conventional gun. We designed simulated dynamics drive 95 GHz, traveling-wave tube experiment at Los Alamos...
A gain experiment was performed at Los Alamos using a 120-keV 2-A cylindrical electron beam with ridged waveguide slow-wave structure 94 GHz, demonstrating 22 dB of amplification through traveling-wave interaction. The planar gap 0.75 mm and length 5 cm. confined in 3.2-kG axial magnetic field, roughly 0.5-mm diameter. aligned along the axis solenoid by scribing out its cyclotron motion on novel optical diagnostic procedure that depends varying solenoidal field strength. transport verified...
A Ba 0.75 Sr 0.25 Ti 0.95 Zr 0.05 O 3 ceramic was developed for use in nonlinear transmission line (NLTL) applications. The sol–gel process used to synthesize nanoparticles achieve a uniform composition and high surface area. Simultaneous thermal gravimetric analysis differential ( TGA/DTA ) identify the decomposition sequence as function of temperature as‐synthesized powders. phase transformation confirmed by X‐ray diffraction XRD ). calcined were hot‐pressed at 1300°C density....
Materials science needs to study dynamic properties of high-Z materials lead a unique and challenging set requirements for future X-ray free-electron lasers (XFELs), with single-pulse fluxes up 1012 50 keV X-rays that are both transversely longitudinally coherent. These parameters cannot be met through an extension the beam FEL technologies used at existing currently planned facilities. We describe novel technique achieve higher by reducing transverse emittance high bunch charges another...
The Los Alamos Advanced Free-Electron Laser uses a high charge (greater than 1 nC), low-emittance (normalized rms emittance less 5/spl pi/ mm mrad), photoinjector-driven accelerator. brightness achieved is due, in large part, to the rapid acceleration of electrons relativistic velocities. As result, beam does not have time thermalize its distribution, and transverse profile is, general, non-Gaussian, This, coupled with very-high brightness, makes it difficult measure emittance. Techniques...
In general, the spatial distributions of electron beams from photoinjectors are unknown and not well approximated by a Gaussian. Therefore, when measuring emittance, it is important to make no assumptions about beam’s distribution. A diagnostic that fulfills this requirement uses beam position monitors measure second moment image charge. This information, coupled with line’s transfer matrix, can be used as an unambiguous root mean square emittance independent Presented here results first...
We report on recent experiments using a magnetic chicane compressor at 8 MeV. Electron bunches both low (0.1 nC) and high (1 charges were compressed from 10–15 ps to less than 1 (FWHM). A transverse deflecting rf cavity was used measure the bunch length charge; charge inferred induced energy spread of beam. The longitudinal centrifugal space‐charge force [Phys. Rev. E 51, 1453 (1995)] is calculated point‐to‐point numerical simulation shown not influence energy‐spread measurement.
A key technology issue of energy recovery linac (ERL) devices for high-power free-electron laser (FEL) and fourth generation light sources is the demonstration reliable, high-brightness, injector operation. Three ongoing programs that target up to 0.5 Ampere photocathode performance with required ERL brightness, are described. The first a DC gun superconducting RF (SRF) booster cryomodule. Such 748.5 MHz device being assembled will be tested 100 mA at Thomas Jefferson National Accelerator...