Abstract: The method and device of the instant invention is a detector of pulsed laser radiation which utilizes the electromotive force generated by the plasma formed when such radiation is focused onto a surface (1). Measurements are made with a 10.6 .mu.m CO.sub.2 laser capable of producing peak intensities of 10.sup.13 W/cm.sup.2 when directed through a converging lens (2). Evacuated detector response to such laser intensity is 1 kV signal peak amplitude and subnanosecond risetimes into a 50.OMEGA. load (3). Detector performance is found to be greatly altered with the introduction of a background gas (4). For example, with one atmosphere of air, the detector produces prompt signals of the order of 1 V with subnanosecond response for pulse trains lasting 100 ns. With argon, krypton, or zenon at pressures of the order of 10 torr, the detector generates "trigger pulses" of about 250 V amplitude and 0.2 ns risetimes.

Abstract: A probe for sensing the direction of flow of an injected current pulse along a conductor of a circuit under test. The probe is linked to automatic test equipment (ATE), and is triggered to inject the pulse during a test sequence at a step previously found by the ATE to establish a faulty state in the circuit so that the faulty one of several components connected to a circuit node can be identified. The probe injects an approximately triangular-waveform current pulse which has a steep rising edge and a less steep falling edge, thereby inducing a voltage level and thus permits discrimination of the direction of current flow. To detect low level current pulses in the presence of masking noise, the output of the probe is connected to the series combination of a filter, an integrator and an A/D converter. The circuit under test is set to its faulty state, and then the probe is repeatedly operated, first with the injection of the current pulses inhibited and then with current pulses being injected.