The VXI electronics of the DIAMANT particle detector array

A VXI card designed for the processing of signals from the particle detector array DIAMANT, a CsI(Tl) light charged particle ancillary detector system to the EUROBALL and the EXOGAM gamma-spectrometers, is described. The card provides particle energy, particle-type and time-reference information and is compatible with the existing signal-processing system of EUROBALL/EXOGAM. In order to have full compatibility with the electronics of these spectrometers without sacrificing the performance of the card, some new solutions are used in the signal processing. For particle discrimination three methods can be selected; the ballistic deficit method, the zero-crossing method and a combination of these two methods. The figure of merit of the particle discrimination using the combined method is better than that of the zero crossing or the ballistic deficit method individually. Timing signals for particle–gamma coincidence are derived by a specially designed non-delay-line constant fraction discriminator, which exhibits low rise-time-dependent walk. The card has been tested with EUROBALL. The results of these tests are presented.