Soviet Research on the Transport of Intense Relativistic Electron Beams through Low-Pressure Air
RAND CORP SANTA MONICA CA
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Soviet research on the propagation of intense relativistic electron beams IREB through air and gases has demonstrated the existence of several pressure ranges for possible efficient IREB propagation. The Soviets have recently paid specific attention to the low-pressure range from .000001 to .001 Torr. Theoretical analysis concentrated on the formation of a quasi-equilibrium beam and the derivation of an expression for its propagation through low- pressure gas, taking into account space-charge forces, self-focusing of the beam, and the effect of the beams own magnetic field on its focusing properties. The analysis involved the determination of equilibrium-beam formation time, relaxation length, density distribution of plasma formed by the passage of the beam, and the effects of beam parameters upon this background plasma. Experimental investigation of the quasi-equilibrium beam demonstrated that it has a Bennett profile, determined the beam formation time, and showed that formation time decreases with increasing pressure and propagation length. For a 300 keV, 100 A beam, transverse beam temperature was found to be 0.5 keV near the beam focus, and 2 keV downstream of the focus. No dependence of beam front velocity upon propagation length had been observed.
- Nuclear Physics and Elementary Particle Physics