Bolometer for Detecting Heat Pulses in a Magnetic Field

The bolometer depends on the rapid temperature variation of the current in an avalanching semiconductor. Typically, at 1.7°K, it has a sensitivity of 0.05 V W−1, a response time of 2×10−7 sec, and a noise equivalent power of 10−7 W Hz−1/2. The rapid response is possible because only a thin damaged layer at the surface of the semiconductor is involved in the detection process. We have used the device to detect heat pulses in magnetic fields up to 30 kOe.