Indirect method to estimate the deadtime of a data acquisition system as a function of the data size.

An indirect method based on timestamp analysis is developed to estimate the deadtime of a data acquisition (DAQ) system as a function of data size (deadtime function). The performance of two types of time-to-digital converter (TDC) modules, the CAEN V1190 and the AMSC AMT-TDC, are studied by applying the proposed method to a test DAQ system built with the TDC modules. With the aid of this method, the DAQ system of the SAMURAI spectrometer at the RIKEN radioactive isotope beam factory (RIBF) is optimized. Through the optimization, the minimum deadtime of one event decreases from about 170 μ s to about 45 μ s. • Deadtime is represented as a function of data size (deadtime function). • A method is developed to evaluate the deadtime function from experimental data. • Deadtime functions of subsystems of a compound DAQ system can be extracted. • Deadtime of SAMURAI DAQ is shortened with the aid of the proposed method. [ABSTRACT FROM AUTHOR]