Methodology for the use of proportional counters in pulsed fast neutron yield measurements

TL;DR

This paper presents a detailed methodology for measuring neutron yield using proportional counters, including calibration, statistical analysis, and application to low emission neutron sources, relevant for fusion and accelerator research.

Contribution

It introduces a comprehensive calibration and analysis method for neutron yield measurement with proportional counters, applicable to various neutron sources and pulse durations.

Findings

Effective efficiency calibration using isotopic neutron sources.

Enhanced detection limits for low emission neutron pulses.

Application to D-D fusion neutron detection systems.

Abstract

This paper introduces in full detail a methodology for the measurement of neutron yield and the necessary efficiency calibration, to be applied to the intensity measurement of neutron bursts where individual neutrons are not resolved in time, for any given moderated neutron proportional counter array. The method allows efficiency calibration employing the detection neutrons arising from an isotopic neutron source. Full statistical study of the procedure is descripted, taking into account contributions arising from counting statistics, piling-up statistics of real detector pulse-height spectra and background fluctuations. The useful information is extracted from the net waveform area of the signal arising from the electric charge accumulated inside the detector tube. Improvement of detection limit is gained, therefore this detection system can be used in detection of low emission neutron pulsed sources with pulses of duration from nanoseconds to up. The application of the methodology to detection systems to be applied for D-D fusion neutrons from plasma focus devices is described. The present work is also of interest to the nuclear community working on fusion by magnetic confinement and lasers, and working on neutron production by accelerators or similar devices.