Implementation of x-ray energy detection and photon counting using a silicon field-emission imaging array

A silicon field-emission array (FEA) was proposed for the implementation of x-ray energy detection and photon counting. The response of single X-ray photon events of differing X-ray energies is modeled showing two pulses with different widths and amplitudes. To verify the theory, a 2cm x 2cm silicon field emission array has been fabricated by subtractive etching and oxidation sharpening techniques. At 450 mum cathode to anode distance and at a vacuum level of 5x107 Torr, the device was biased at 1400V, field emitting at an integrated current of 32pA. When the device was excited by a 100muCi Fe55 X-ray source, an average increase of 24pA was observed.