Liquid Xe homogeneous electro-magnetic calorimeter

We constructed a liquid xenon calorimeter with electrodes of multi-parallel plates. This calorimeter is regarded as homogeneous because of thin electrodes and is expected to have an excellent energy resolution of 0.34% for 70 GeV electrons by EGS4 simulation. We tested it for 10–70 GeV electrons at CERN. The measurements were made without signals from a readout channel at about 4 radiation length lost by failure. By simply summing other signals the energy resolution of 2% (r.m.s.), which includes the beam momentum spread of 0.65%, was obtained for 70 GeV electrons. The signal from the lost channel can be estimated by fitting a build-up curve to the obtained signals for each event. If the correction for the contribution from the lost channel is made by the fitting method, the energy resolution is 0.9%, which is close to the resolution of 0.71% obtained by the simulation.