The TOT Method with a Pulse Shaper Based on a Raised-Cosine Filter

The time over threshold (TOT) method that uses a pulse sine shaper, which is based on the mathematical function of the raised cosine (FRC), is described. The FRC has an important property for the TOT method—the formation of a smooth pulse with the variability of both the smoothing coefficient and the response time. In this case, the shape of the FRC pulse is independent of the input pulse action within a given time range. Thus, on the basis of the FRC, it was possible to create a pulse sine shaper with a preset time response, which provided an unambiguous dependence of the TOT-pulse duration on the input charge, and to improve the accuracy characteristics due to optimal spectral filtering in the FRC. A pulse sine shaper based on the FRC was successfully used in the reading systems of the HADES (GSI, Darmstadt, Germany) and BM&N (JINR, Dubna) experiments. The total number of reading channels was more than 5000; the method has an error of ~0.3%.