Proton-sensitive custom SRAM detector

A custom 4k-bit static RAM (SRAM) chip was tested with protons. The SRAM was developed to determine the single event upset hardness of hardness of CMOS latches using alpha particle measurements and can also function as a proton detector. The authors describe a calibration procedure for the SRAM detector, allowing spectrometers to be designed for measuring proton, helium, and heavier ion environments inside spacecraft computers. The detector was calibrated for protons using the Caltech Tandem Van de Graaff. The SPICE circuit simulation program was used to compute an effective calibration curve and this curve was then used, with the proton data, to compute an effective charge collection depth, allowing calibration