A novel radiation imaging sensor based on self-activated pixels

A new position sensitive detector for charged particles and X-rays is proposed based on pixels containing MOS transistors as preamplifiers. The output of the preamplifiers is shorted to strip buses to obtain two-dimensional information with readout requirements similar to a strip detector. The total pixel capacitance is low enough (20-40 fF) to allow a large potential increase at the pixel that collected the charge. The nonlinearity introduced by the large voltage rise effectively switches on the transistors of this pixel and leaves all the other pixels of the same line at a low transconductance state, resulting in an excellent noise performance.< >