On the possibility of particle identification with different charges in photonuclear reactions

A detector is described which is intented for the detection and identification of particles with charges Z>=1, produced in photonuclear reactions. The detector consists of a wide-gap spark chamber for measuring the residual range, and a multiwire proportional chamber (MPC) for measuring ionization losses. A mixture of He+1.5% CH4 or Ne+1.5%CH4 is pumped through the working volume of the detector. The distinguishing feature of the detector is the possibility to measure the spectral distribution of pulses from the MPC, and to accommodate within its volume four Al targets. The detector allows the detection of particles in the angular range from 60 to 120 deg relative to the direction of a primary photon beam throughout the energy range 1.5 - 30 MeV. Experimental results are given of the amplitude spread of pulses from the MPC, depending on the residual range when the detector is irradiated with a photon beam