Speaker
Description
A compact beta spectrometer (10×10×12 cm$^3$) has been developed for electron spectrometry in challenging radiation environments, including low Earth orbit and nuclear reactor interiors, where intense gamma backgrounds complicate spectral measurements. The spectrometer uses a telescopic configuration of single-area silicon detectors, allowing the gamma field to be discriminated against while measuring the electron spectrum. A new custom digitization system has been developed to match the instrument's form factor. Additionally, a custom front-end module housing high-voltage supplies and preamplifiers has been developed and integrated into the instrument. The pulse processing system implements online timing coincidence and energy logic, allowing real-time extraction of the beta field spectrum. Geant4 simulations of the instrument are used to determine the spectrometer response function and reconstruct the beta fluence rate spectrum from the pulse height spectra collected. A commercial pulse processing system with offline timing coincidence and energy logic has been assembled and connected to the silicon detector stack to act as a reference system. The instrument is tested using multiple combinations of $^{137}$Cs gamma sources, $^{137}$Cs internal conversion sources, and $^{90}$Sr/$^{90}$Y beta sources. System linearity, noise floor, energy resolution, timing resolution, dead-time characteristics, and accuracy of spectral reconstruction are presented and compared to Geant4 simulations and the commercial pulse processing system.