An attempt to build a statistical model for a PIPS detector operated in a real-time mode

Basic approaches by K.-H.Schmidt and V.B.Zlokazov to estimate the probability of registered multichain event to be explained by random coincidences are considered. A specific feature of the long-term experiments aimed at the synthesis of superheavy nuclei with the Dubna Gas-Filled Recoil Separator is usage of a real-time mode for radical suppression of background products. In fact, this assumes that the first correlation group, namely, recoil-alpha correlation, stops target irradiation for a short time and the forthcoming signals are detected in more favourable background conditions. Due to the application of this detection mode the first recoil-alpha chain can be considered as a 'starter' for the detection of the forthcoming alpha-particle signals with high background suppression. This fact is taken into account in the given PIPS detector statistical model