1,893 research outputs found
Concerning a new classification of tricyanides
A new classification series of tricyanides is presented. Several tricyanides are synthesized by a simple method from aluminum chloride, benzonitrile, and a respective alkyl or phenyl chloride, purified by recrystallization and distillation, and then analyzed. Structural formulae are suggested, and molecular weights, melting points, and boiling points are determined for each
Combining Harmonic Generation and Laser Chirping to Achieve High Spectral Density in Compton Sources
Recently various laser-chirping schemes have been investigated with the goal
of reducing or eliminating ponderomotive line broadening in Compton or Thomson
scattering occurring at high laser intensities. As a next level of detail in
the spectrum calculations, we have calculated the line smoothing and broadening
expected due to incident beam energy spread within a one-dimensional plane wave
model for the incident laser pulse, both for compensated (chirped) and
unchirped cases. The scattered compensated distributions are treatable
analytically within three models for the envelope of the incident laser pulses:
Gaussian, Lorentzian, or hyperbolic secant. We use the new results to
demonstrate that the laser chirping in Compton sources at high laser
intensities: (i) enables the use of higher order harmonics, thereby reducing
the required electron beam energies; and (ii) increases the photon yield in a
small frequency band beyond that possible with the fundamental without
chirping. This combination of chirping and higher harmonics can lead to
substantial savings in the design, construction and operational costs of the
new Compton sources. This is of particular importance to the the widely popular
laser-plasma accelerator based Compton sources, as the improvement in their
beam quality enters the regime where chirping is most effective.Comment: 5 pages, 4 figure
Regional And Global Energy Transfer Via Passive Power Relay Satellites
The movement of energy is a basic requirement of our industrial civilization. Therefore, power transmission is a component of the energy confrontation concerning this country. It is an even more important aspect of mankind\u27s global energy future.
The reason for this is that the development of new power sources and improvements in the distribution of conventional sources depend on the extent to which energy can be moved freely from its primary source to the load centers. There is no lack of energy in this country or on this planet, if nuclear, solar, geothermal and other primary sources are taken into consideration.
But it becomes increasingly desirable to remove nuclear and fossil power plants from heavily populated or biologically sensitive areas and to utilize geographically less conveniently located solar or geothermal energy sources. Such developments require, or at least are facilitated by, the ability to transfer energy economically and reliably over large distances, including wilderness areas, large bodies of water or mountain ranges, at little or no interference in, or threat to the regional ecology
Multiple Scattering of Electromagnetic Waves by an Array of Parallel Gyrotropic Rods
We study multiple scattering of electromagnetic waves by an array of parallel
gyrotropic circular rods and show that such an array can exhibit fairly unusual
scattering properties and provide, under certain conditions, a giant
enhancement of the scattered field. Among the scattering patterns of such an
array at its resonant frequencies, the most amazing is the distribution of the
total field in the form of a perfect self-similar structure of chessboard type.
The scattering characteristics of the array are found to be essentially
determined by the resonant properties of its gyrotropic elements and cannot be
realized for arrays of nongyrotropic rods. It is expected that the results
obtained can lead to a wide variety of practical applications.Comment: 5 pages, 6 figure
Longitudinal phase space manipulation in energy recovering linac-driven free-electron lasers
Energy recovering an electron beam after it has participated in a
free-electron laser (FEL) interaction can be quite challenging because of the
substantial FEL-induced energy spread and the energy anti-damping that occurs
during deceleration. In the Jefferson Lab infrared FEL driver-accelerator, such
an energy recovery scheme was implemented by properly matching the longitudinal
phase space throughout the recirculation transport by employing the so-called
energy compression scheme. In the present paper,after presenting a
single-particle dynamics approach of the method used to energy-recover the
electron beam, we report on experimental validation of the method obtained by
measurements of the so-called "compression efficiency" and "momentum
compaction" lattice transfer maps at different locations in the recirculation
transport line. We also compare these measurements with numerical tracking
simulations.Comment: 31 pages, 13 figures, submitted to Phys. Rev. Special Topics A&
Comment on Controlling the Spectral Shape of Nonlinear Thomson Scattering With Proper Laser Chirping
Rykovanov, Geddes, Schroeder, Esarey and Leemans [Phys. Rev. Accel. Beams 19, 030701 (2016); hereafter RGSEL] have recently reported on the analytic derivation for the laser pulse frequency modulation (chirping) which controls spectrum broadening for high laser pulse intensities. We demonstrate here that their results are the same as the exact solutions reported in Terzic, Deitrick, Hofler and Krafft [Phys. Rev. Lett. 112, 074801 (2014); hereafter TDHK]. While the two papers deal with circularly and linearly polarized laser pulses, respectively, the difference in expressions for the two is just the usual factor of 1/2 present from going from circular to linear polarization. In addition, we note the authors used an approximation to the number of subsidiary peaks in the unchirped spectrum when a better solution is given in TDHK
Driver Accelerator Design for the 10 kW Upgrade of the Jefferson Lab IR FEL
An upgrade of the Jefferson Lab IR FEL is now under construction. It will
provide 10 kW output light power in a wavelength range of 2-10 microns. The FEL
will be driven by a modest-sized 80-210 MeV, 10 mA energy-recovering
superconducting RF (SRF) linac. Stringent phase space requirements at the
wiggler, low beam energy, and high beam current subject the design to numerous
constraints. These are imposed by the need for both transverse and longitudinal
phase space management, the potential impact of collective phenomena (space
charge, wakefields, beam break-up (BBU), and coherent synchrotron radiation
(CSR)), and interactions between the FEL and the accelerator RF system. This
report addresses these issues and presents an accelerator design solution
meeting the requirements imposed by physical phenomena and operational
necessities.Comment: submission THC03 for LINAC200
Design of Electron and Ion Crabbing Cavities For an Electron-Ion Collider
Beyond the 12 GeV upgrade at the Jefferson Lab a Medium Energy Electron-Ion Collider (MEIC) is being considered. In order to achieve the desired high luminosities at the Interaction Points (IP), the use of crabbing cavities is under study. In this work, we will present up to date designs of superconducting cavities, considered for crabbing both ion and electron bunches. A discussion of properties such as peak surface fields and Higher Order Modes (HOMs) separation will be presented
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