Abstract :
A practical technique to correct the dead time effect in the variance-to-mean ratio measurement is proposed. A correction formula used in the technique is derived based on a simple mechanism of count loss due to a non-extending dead time. The technique was verified with a Monte Carlo simulation and an experiment in Deuterium Critical Assembly. It was confirmed that the formula can make a reasonable correction to the case that the count loss is as large as 50%. This correction technique is extremely simple and can make the correction only with data obtained in the original measurement.