Design parameters and technology optimization of 3He-filled proportional counters for thermal neutron detection and spectrometry applications

Technological aspects and key features related to the development and design optimization of 3He-filled proportional counters for thermal neutron detection and neutron spectrometry applications are presented in this article. Basic operation features are reviewed in details by focusing on their determinant impact upon the definition of the consistent design parameters. Previous Monte Carlo simulations, where both wall effect and electron attachment effects due to occlusive electronegative impurities were taken in consideration, were carried out in 3He-filled proportional counters for the study of the pulse height distribution and gamma rays influence. From interpretation of the main quantitative results, basic parameters for design optimization requirements were drawn-up. Some laboratory developed 3He-based proportional counter prototypes are then described. The characteristics of a set of gas composition fillings that were experimentally investigated are then compared to those obtained with a commercial specimen that was taken as a reference standard. Finally, a brief conclusion underlines some consistent insights toward the improvement of quality performances during future development tasks of helium-filled proportional counters intended for thermal neutron detection and neutron spectrometry applications.

► Technological aspects and design of 3He neutron proportional counters are reviewed.
► Pulse height distribution of the counters were simulated by Monte Carlo code.
► Some laboratory developed 3He-based proportional counter prototypes are described.
► A set of gas composition fillings were experimentally investigated.