Beam-based alignment in RHIC

Abstract

A new measurement procedure and a new data analysis algorithm have been introduced to alleviate the difficulties faced by beam-based alignment (BBA) tasks in RHIC. New codes were also developed to implement the new methods in measurements and analysis correspondingly. These improvements have enabled us to successfully perform BBA during the RHIC 2012 and 2013 runs. The BPM offset corrections calculated from the BBA results were implemented and significant improvements were seen in most of the before-and-after comparisons. Here we discuss the measurability and other important BBA issues in RHIC. We present the new measurement procedure, new data analysis algorithm and the new codes that have been developed. We summarize the BBA measurements, analysis, and corrections in RHIC to date. The BBA accuracy limitations are also discussed. As a continuing effort, we also present application code that is under development for future BBA operations in RHIC.