A pulsed detection system developed for the study of photoexcited carriers in insulating crystals is described. Positive and negative voltages are repetitively applied to the specimen placed between blocking electrodes. Transient photocurrents are then excited by repeated xenon flash illumination and detected by a transistorized charge-sensitive preamplifier. The pulses are amplified by a linear pulse-amplifier and averaged by a two-channel boxcar integrator. Photocurrents may be directly plotted as a function of some external parameter, such as temperature or magnetic field. The rms noise of the input stage is equivalent to a single charge pulse of 450 electrons but repeated pulses of 5 electrons each can be detected by averaging over a period of 90 sec. A differential technique used in cyclotron resonance experiments is described.
No takes yet. Share an insight, caveat, or question.
Borders et al. (1968) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: