Progress on the Absorber Focus Coil Module for the MICE Channel

M. Green, Y, Ivanyushenkov, W. Lau, S. Senannayake, S. Yang

for the

MICE Collaboration

Abstract

This report describes the progress on the absorber focus coil module for the international Muon Ionization Cooling Experiment (MICE). The MICE absorber focus coil module consists of a pair of superconducting solenoids, mounted on an aluminum mandrel. The coil package that is in its own vacuum vessel surrounds an absorber, which does the ionization cooling of the muons. The absorber is within a separate vacuum vessel that is within the warm bore of the superconducting magnet may be either a liquid or solid absorber. The liquid absorber will be filled with either liquid hydrogen or liquid helium. The solid absorbers used in MICE will be made from a low z material such as lithium, lithium hydride, beryllium, or a plastic (C_NH_2N+2). The superconducting focus coils may either be run in the solenoid mode (with the two coils at the same polarity) or in the flip mode (with the coil at opposite polarity causing the field direction to flip within the magnet bore). The superconducting coils will be cooled using a pair of small 4 K coolers. Because the intensity of the muon beam in MICE is low, the liquid absorber will be cooled using a single small 4 K cooler. The solid absorbers will be radiation cooled.