A new four channel pulse shape discriminator

A renewed interest in neutron - gamma discrimination and the need to process rates up to several MHz per channel led to the development of a new, four channel pulse shape discriminator (PSD) in 1/12 NIM format. By revisiting old techniques and running simulations of new ideas, it was determined that the best PSD performance is obtained by measuring the time between the rising edge of the pulse and the intersection point of the curves of the integrated short component with the trailing edge of the pulse. Pulse shape discrimination can be performed at up to 4 MHz detector rate. The module was tested with different neutron and gamma sources as well as at high neutron flux and was found to provide good energy independent neutron / gamma discrimination in a wide energy range with low dead time. A 96-channel system using 24 of these modules is now being operated.