Experimental study of positron production from a 2.55-mm-thick silicon crystal target using 8-GeV electron beams with high-bunch charges

[摘要] We have investigated quenching phenomena of channeling radiation through positron production from a silicon crystal hit by a single-bunch electron beam with high-bunch charge at the 8-GeV electron/positron injector linac. The crystal axis, (I 10), was aligned to the electron beam with a precise goniometer, and positrons produced in the forward direction with a momentum of 20 MeV/c were detected with a magnetic spectrometer. Positron yields were measured by varying the charge in a bunch with a typical bunch length of -10 ps from 0.1 nC to 2 nC. The corresponding instantaneous current density ranged from 0. 15 x 10(4) to 1.2 x 10(4) A/cm(2). The results show that, at these current densities, the positron yield is proportional to the bunch charge within the experimental accuracy, which implies that no non-linear phenomena are observed in channeling radiation. (c) 2006 Elsevier B.V. All rights reserved.

[发布日期] 2006-11-01

[效力级别]  Proceedings Paper

[关键词] channeling radiation;coherent bremsstrahlung.;positron source;crystal target;solid-state plasma