# Dead Time of Non-Paralyzable Data-Acquisition Systems

The amount of recorded data of a triggered data acquisition system depends on the rate of triggers delivered to the system and on the time it takes to processs one event. In the case of non-paralyzable detectors and electronics the ratio between the number of delivered events D and recorded events R can be calculated for random time distributions of the events for a given dead time T as:

R = D / (1 + D*T)

Example:

Let the time to process one event be T=120 micro-secs and incident count rate is 5000/s.
Then, the dead time fraction R/D = 62.5%.

R = D exp (-D*T) The above figure shows the number of accepted events as a function of the number of incident events for a non-paralyzable data acquisition system. The listmode readout of the cluster detector has a typical dead time of 120 micro-secs. The above figure shows the number of accepted events as a function of the number of incident events for a paralyzable data acquisition.

Reference: W.R.Leo: Techniques for Nuclear and Particle Physics Experiments, Springer-Verlag Berlin, 2nd edition, page 122ff