Self-Adjusting Bias-Resistor Unit for a Semiconductor Detector

A self-adjusting resistor unit is described that stabilizes the bias voltage of a semiconductor detector, while always keeping the parallel thermal noise of the bias resistor significantly below the detector shot noise. The user is exempted from adjusting the bias resistor to the detector leakage current for achieving optimum operating conditions. Moreover, the unit avoids the drop of the operation voltage on the detector when the reverse current increases up to several orders of magnitude without any further intervention. The self-adjusting unit can lead to a significant extension of the time of operation of the detector under stable conditions.