Design and Construction of a Multi-Channel Logarithmic Analyzer for Extending Energy Measurement Range in Radioactive Radiation Spectroscopy

Abstract

In this research, we designed and constructed a multi-channel logarithmic analyzer capable of simultaneously measuring nuclear events in mixed fields with both high and low energies. This analyzer is essential for microdosimetry, where continuous spectra in the range of \(\varvec{10^{-2}}\) keV to \(\varvec{10^3}\) keV must be observed. As the energy measurement range increases, the pulse height analysis range also expands, necessitating improvements in the analyzer’s performance for pulse height analysis. The use of high-voltage amplifiers and block sampling in this multi-channel logarithmic analyzer enables pulse height analysis up to \(\varvec{10^5}\) mV. We validated the analyzer using a signal generator, observing spectra corresponding to pulse heights of \(\varvec{3\times 10^0}\), \(\varvec{3\times 10^1}\), \(\varvec{3\times 10^2}\), \(\varvec{3\times 10^3}\), and \(\varvec{3\times 10^4}\) mV in channels 394, 1208, 2030, 2849, and 3666, respectively. In simultaneous gamma-ray spectroscopy using Am-241 and Co-60 sources and pulses from a pulse generator with an amplitude of 32,000 mV, the designed logarithmic analyzer detected all energy peaks, whereas the linear MCA detected only some peaks. The logarithmic analyzer, with a 16-bit conversion gain in the \(\varvec{10^5}\) keV energy range, provides optimal energy resolution compared to lower conversion gains and linear MCA.