Alpha Response of Microchannels in a Diamond Detector

Diamond-based alpha detectors are highly effective for detecting alpha particles due to their exceptional properties, including a wide bandgap, high radiation hardness, and fast charge carrier mobility. These characteristics contribute to excellent energy resolution, low noise, and reliable operation in harsh environments, making them suitable for applications in nuclear research and security. This study presents the fabrication and preliminary testing of a diamond-based detector with integrated microchannels (MCs) designed to enhance geometric efficiency by minimizing alpha particle displacement prior to detection. The detector was fabricated using femtosecond laser processing and reactive ion etching on a diamond substrate, followed by chromium/gold metallization for signal collection. A low-activity uranium source was electroplated onto a tungsten probe and aligned into one of the MCs. Monte Carlo simulations using MCNP were used to estimate expected alpha counts, which showed reasonable agreement with measured spectra, validating the detector design and demonstrating its feasibility for low-activity alpha spectrometry.