Test of the electron hose instability in the E157 experiment

摘要

The E157 experiment is designed to demonstrate high gradientplasma wake field acceleration over a significant length. It has beensuggested that the electron hose instability of the drive beam willdegrade the performance of this experiment because the hosing tailelectrons will not fully sample the highest acceleration field. In thispaper a parasitic experiment designed to test the extent of the hosinginstability is described. In particular, we discuss how the initial beamconditions are determined so that the extent to which any transverseperturbations grow due to hosing can be determined