Results 251 to 260 of about 1,058,891 (298)

Spreading of Intense Laser Beams Due to Filamentation

Physical Review Letters, 1994
Channeling and filamentation of a laser beam is investigated experimentally and via computer simulations. A two-dimensional, fully nonlinear, fluid code has been developed and used to simulate the propagation of a laser pulse through an underdense plasma when [ital v][sub osc]/[ital v][sub [ital e]][similar to]1.
, Wilks, , Young, , Hammer, , Tabak, , Kruer   +4 more
openaire   +2 more sources

The spreading of a proton beam by the atmosphere

Planetary and Space Science, 1972
A simplified approximate expression is analytically derived for the spreading by charge exchange of a fine proton beam precipitating into the atmosphere. It shows in a simple way the dependence of proton beam spreading on atmospheric structure, collision data, primary particle energy, and pitch angle.
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Beam Spreading Devices

2011
Effective use of a particle beam for radiotherapy necessitates delivery of that beam in such a way that it covers the target volume with a prescribed dose distribution. The particle beam extracted from an accelerator normally has beam dimensions smaller than that of a typical target. Therefore, that beam has to be spread out to match the target volume.
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Beam Spread with the Princeton FM Cyclotron

Review of Scientific Instruments, 1964
Two methods have been employed on the Princeton 18-meV FM cyclotron to increase the duty cycle of the proton beam. In the first method, the dee oscillator was cut off just before normal beam extraction and turned on again about 50 μsec later. A moderate beam spread is produced. In the second method, an auxiliary accelerating electrode, in the form of a
H. O. Funsten, N. R. Roberson, A. Lieber, R. Sherr   +3 more
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Beam Spreading of Partially Coherent Beams Propagating through Turbulence Atmospheric in Boundary Layer

Advanced Materials Research, 2011
The cross-spectral density function of the partially coherent beam on 1.06μm is extended based on the generalized Huygens-Fresnel principle by using the Gaussian Schell-mode(GSM) and the modified Frehlich spectrum. And on the analysis of variation of the
Ming Gao, Hong Lv
exaly   +2 more sources

Beam spreading of truncated Gaussian beams in Kolmogorov turbulence

Optics Communications, 2010
Abstract Based on the extended Huygens–Fresnel principle and the hard-edge aperture function expanded as the sum of finite-term complex Gaussian function, analytical expression for average intensity of truncated Gaussian beam in Kolmogorov turbulence is derived, and some limiting cases are discussed.
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Anomalous Energy Spreads in Electron Beams

Journal of Applied Physics, 1966
Energy distributions of 2- to 10-eV electron beams were measured in a deflection analyzer. The performance of the analyzer was monitored by use of a second one in tandem. In agreement with earlier measurements in high-energy beams the energy distribution varied with current.
J. Arol Simpson, C. E. Kuyatt
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Study on the Flange Spread of H-Beam

Advanced Materials Research, 2014
According to the production data of a rolling H-beam factory, the FE model of hot continuous rolling process of H-beam is built. The rolling process of H-beams is simulated by explicit dynamic FEM, and the influence of deformation parameters on the spread of rolling piece is analyzed.
Jin Hong Ma, Xiao Han Yao, Bin Tao
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An electron gun and beam spreading.

1956
Wagner, S. (Supervisor)
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An Asymptotic Model for the Spreading of a Collimated Beam

Nuclear Science and Engineering, 1992
In this paper, the authors show, using asymptotics, that under conditions when the angular distribution is forward peaked, the transport equation can be reduced to an advection-diffusion equation for the scalar flux. This equation describes lateral diffusive spreading with depth of an initially collimated beam of arbitrary spatial cross section and is ...
G. C. Pomraning, A. K. Prinja, J. W. VanDenburg   +2 more
openaire   +1 more source