A field-based technique for the longitudinal profiling of ultrarelativistic electron or positron bunches down to lengths of /spl les/10 microns

摘要

Present and future generations of particle accelerating and storage machines are expected to develop ever-decreasing electron/positron bunch lengths, down to 100 /spl mu/ and beyond. In this paper a method for measuring the longitudinal profiles of ultrashort (1000 /spl muspl ap/10 /spl mu/) bunches, based on: 1) the extreme field compaction attained by ultrarelativistic particles, and 2) the reduction of the group velocity of a visible light pulse in a suitably-chosen dielectric medium, is outlined.