A Novel Method for Simulating Transient Signals in Diamond Thermal Neutron Detectors

Abstract

Neutrons have extensive applications across a wide range of fields. Diamond, with its excellent physical properties, holds great promise for neutron detection. However, the probability of thermal neutron interaction with diamond is relatively low, leading to the common use of ⁶LiF as a conversion layer. Beyond the inherent properties of the conversion layer, the detection efficiency of a detector is influenced not only by the spatial collection of secondary particles but also by the electrical characteristics of the device. Theoretical simulations can extract important parameters of the device and reveal significant physical processes. This article establishes a simulation framework using technology computer-aided design (TCAD), stopping and range of ions in matter (SRIM), and Garfield++. The simulation process involves using Sentaurus TCAD software to model the electrical characteristics of diamond detectors, employing SRIM to accurately simulate the deposition energy interaction of charged secondary particles with diamonds, and leveraging Garfield++ to generate detector signals accurately using electrical characteristics and nuclear reaction data. By simulating the signals of both planar and trench-type microstructure detectors, the research explores the impacts of various factors, including the applied voltage, the energy of secondary particles, and the angle of incidence on the dynamic response process. The proposed coupled simulation method plays a key role in the fabrication and experimental design of thermal neutron detectors, providing crucial insights and guidance to optimize detector performance and design readout circuits.