Initial nonintercepting measurements of subpicosecond bunches using coherent diffraction radiation.

Lumpkin, A. H. ; Sereno, N. S. ; Decker, G. A. ; Rule, D. W.

Technical Information Center Oak Ridge Tennessee

关键词: Diffraction;    Beam bunching;    Beams;    Measuring instruments;    Beam monitoring;   

RP-ID  :  DE2001757526

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

We report initial measurements of the subpicosecond (sub-ps) bunch structure in a 40-MeV linac beam using the autocorrelation of far infrared (FIR) coherent diffraction radiation (CDR). Since the radiation was generated as the charged particles passed through a slit or aperture in a metal screen oriented at 45 degrees to the beam direction, this is a nonintercepting technique. A compact Michelson interferometer was used to obtain the autocorrelation of the backward CDR with a Golay cell used as the FIR-mm wave detector. The longitudinal shape was calculated from the autocorrelation using the minimal phase approximation. A model as developed and used to calculate the CDR spectral emissions. The experimental results, analysis, and model are presented. Complimentary measurements were also made with coherent transition radiation (CTR).