Beam Quality Measurements for Low Energy Antiproton Machines

Abstract

From 2016 the Extra Low Energy Antiproton (ELENA) ring will allow better quality, higher intensity antiproton beams to reach the experiments at the antimatter facility at CERN. Also currently in development is the Ultra-low energy Storage Ring (USR) at the Facility for Low-energy Antiproton and Ion Research (FLAIR). In order to ensure the experiments receive the best quality beams possible, unique diagnostics systems for these machines must be developed. In this contribution, a system using a scraper for measuring the emittance of beams in next generation low energy antiproton machines is investigated. After developing a working theory, particle tracking using multiple codes is performed to establish a reliable simulation of the scraper in operation. The working scraper model is used to determine how accurately the emittance of the beam can be reconstructed from scraper position and beam intensity measurements. As there is no point of zero dispersion around the ELENA ring, several complications are considered. These include difficulties determining the closed orbit and the effects of a correlation between the emittance and momentum offset. An algorithm employing the best possible method of reconstruction is developed and offered for practical application. Additional effects such as a diffusion process and intrabeam scattering may further complicate the measurement and possible future studies are discussed. Challenges arising from the adaption of the device from ELENA to the USR are considered.