Neutron Lifetime Experiments Using Magnetically Trapped Neutrons: Optimal Background Correction Strategies

Published

August 1, 2001

Author(s)

Kevin J. Coakley

Abstract

In the first stage of each run of a neutron lifetime experiment, a magnetic trap is filled with neutrons. In the second stage of each run, decay events plus background events are observed. In a separate experiment, background ismeasured. The mean lifetime is estimated by fitting a two parameter exponential model to the background-corrected data. For two models of the background signal, I determine the optimal ratio of the number of background-only measurements to the number of primary neutron decay plus background measurements. Further, for each run, I determine the optimal allocation of time for filling and for observing decay events. For the case where the background consists of an activated material (aluminum) plus a stationary Poisson process, the asymptotic standard error of the lifetime estimate computed from the background-corrected data is lower than the asymptotic standard error computed from the uncorrected data. For the case where the background is a stationary Poisson process, background correction is desirable provided that the background intensit is sufficiently small compared to the rate at which neutrons enter the trap.

Citation

Nuclear Instruments & Methods in Physics Research Section A-Accelerators Spectrometers Detectors and Associated Equipment

Volume

469

Issue

No. 3

Pub Type

Journals

Keywords

Experiments, magnetically trapped neutrons

Citation

Coakley, K. (2001), Neutron Lifetime Experiments Using Magnetically Trapped Neutrons: Optimal Background Correction Strategies, Nuclear Instruments & Methods in Physics Research Section A-Accelerators Spectrometers Detectors and Associated Equipment (Accessed October 10, 2025)