Counting anticoincidences to reduce statistical uncertainty in the calibration of a multiplicity detector

Abstract The observation of anticoincidences reduced statistical uncertainties as well as pileup corrections in the efficiency calibration of a multiplicity detector. The efficiency of the 4 π gadolinium-loaded organic scintillation detector was measured for detecting capture of neutrons scattered by the hydrogen in a second detector. In such situations the effect of background upon the counting fluctuations is reduced below the value that would occur if the average counting rate during coincidence gates were utilized. The applicable formulae were obtained by elementary methods and were verified with experimental data and with computer simulations for a broad range of detector efficiencies and background intensities. The general requirements for use of the technique are indicated.