文档介绍：A HEAT EXCHANGER BETWEEN FORCED FLOW HELIUM
GAS AT 14 TO 18 K AND LIQUID HYDROGEN AT 20 K
CIRCULATED BY NATURAL CONVECTION
M. A. Green1, S. Ishimoto2, W. Lau3, and S. Yang3
1Lawrence Berkeley National Laboratory, Berkeley CA 94720, USA
2KEK, 1-1 Oho, Tsukuba, 305-0801, Japan,
3Oxford University, OX1, 2JD, Oxford UK
ABSTRACT
The Muon Ionization Cooling Experiment (MICE) has three 350-mm long liquid
hydrogen absorbers to reduce the momentum of 200 MeV muons in all directions. The muons
are then re-accelerated in the longitudinal direction by 200 MHz RF cavities. The result is
cooled muons with a reduced emittance. The energy from the muons is taken up by the liquid
hydrogen in the absorber. The hydrogen in the MICE absorbers is cooled by natural
convection to the walls of the absorber that are in turn cooled by helium gas that enters at 14 K.
This report describes the MICE liquid hydrogen absorber and the heat exchanger between the
liquid hydrogen and the helium gas that flows through passages in the absorber wall.
INTRODUCTION
The muon ionization cooling experiment (MICE) uses liquid hydrogen absorbers to
absorb energy from a beam of 200 MeV/c muons. This energy absorbed is in both the
longitudinal and the transverse directions. Energy is put back into the muons in the
longitudinal direction. If the heating due to scattering is less than the cooling thr