Synthesis and evaluation of a charge sensitive amplifier for neutron counters

Abstract

Cosmic-ray fluctuations are monitored by neutron monitors using several different kinds of proportional counter tubes. An important component of these monitors is the electronic subsystem that registers and counts output pulses from these counter tubes. Part of the electronic subsystem is a specific preamplifier. The pulse-height distribution curve of the existing preamplifier used in the neutron monitor system at the Centre for Space Research at the North-West University was found to be incorrect, and therefore the pulse-height information cannot be used for further research on the counter tube characteristics. A correct pulse-height distribution implies that the envelope of the pulse, as generated by an amplifier, has a very specific shape as a result of the physics that governs the generation of pulses in the neutron counter tube. It was therefore proposed that a new charge-sensitive preamplifier be synthesized to provide an output that provides the correct pulse-height distribution graph for a neutron monitor system. The Centre for Space Research at the North-West University is in the process of designing and building a new mini neutron monitor system. The new charge-sensitive preamplifier will be implemented into this updated system. Ultimately, the electronic subsystem must be able to provide a pulse-height distribution graph at the push of a button, thus making the preamplifier a key component in the new design. In this dissertation the theory of charge-sensitive amplifiers is researched following a design science research methodology. The results showed that a charge-sensitive amplifier can be synthesized to address both the real-world requirements and the theoretical requirements of this research.