Proposed Interim Improvement to the Tevatron Beam Position Monitors with Narrow Band Crystal Filters

摘要

Since the start of Run II, we have found that we are unable to reliably and accurately measure the beam position with the present BPM system during high energy physics (HEP). This problem can be traced back to the analogue front-end called the AM/PM module which has trouble handling coalesced beam, but works well with uncoalesced beam. In this paper, we propose a simple fix to the AM/PM module so that we can measure the beam position during HEP. The idea is to use narrow band crystal filters which ring when pinged by coalesced beam so that the AM/PM module is tricked into thinking that it is measuring uncoalesced beam.