EXPERIMENTAL STUDY OF BEAM COLLIMATION IN LOW ENERGY PROTON RINGS ∗

With a maximum level of uncontrolled loss of 10−4 of the total beam, the design of the Spallation Neutron Source (SNS) accumulator ring is severely constrained by loss budget considerations. It is then mandatory to have an accurate prediction of the collimation systems efficiency and uncontrolled loss distribution at low energy (1 GeV). Significant effort is being invested in benchmarking of the codes for collimation simulation at SNS. In particular, we are performing experiments in the U-70 ring at Protvino, Russia. This proton machine can operate at 1.3 GeV, close to the SNS baseline of 1 GeV. In these experiments, we plan to measure the dependence of the collimation efficiency on the impact parameter. We also study the behavior of dif-ferent materials when used as primary scrapers. This paper describes the experimental setup and procedures for the ex-periment and presents the first experimental results.