A Dual Threshold Method to Independently Control Spatial Resolution and Sensitivity in β Imaging

A wide variety of digital alternatives have been presented to replace traditional film emulsion as detection medium in βAutoradiography. The main claim of most of the alternatives is higher sensitivity. On the other hand, spatial resolution remains the main problem to solve to be able to offer a sensible alternative to film. Solid state detectors, mainly made of silicon, are being used very actively in many disciplines in Medicine and Biology. Spatial resolution is significantly dependant on the pixel size for digital detectors. If charge deposition from impinging βparticles causes cross-talk between neighbour pixels, and accurate charge deposited is measured, sub-pixel resolution can be obtained, therefore potentially obtaining spatial resolution comparable to traditional film. In order to investigate this, a dual threshold approach is presented here, validated with Monte Carlo simulations. Using this approach better charge measurement is obtained, and even some background events are discarded, reducing the global noise level of the detector.