Drift-Collection Calorimeter

A new geometry is presented for a gas-sampling calorimeter in which ionization electrons are collected by drifting to a central PWC. The arrangement is applicable to both hadronic and electromagnetic calorimeters. It allows great flexibility in segmentation of readout and in longitudinal segmentation of the radiator, while allowing the number of proportional wires to remain low. With full instrumentation on each sense wire, the calorimeter can provide a three-dimensional image of the cascade, giving maximum information on its development. Tests of the system have been made in an electron bean and with cosmic rays. It has been demonstrated that ionization electrons are collected efficiently and that good resolution and linearity of electron energy measurement are achieved.