[en] The paper describes the operating principles of the electronic readout system as used on the Mk II R.A.L. positron camera. The individual modules are described in detail, and the specifications and the performance figures for the individual units, and of the complete system are given. Some early results obtained with the full system are presented. (author)

[en] A combination of radiofrequency heater adapted to receive thermoluminescent dosimetry discs, equipment for counting light emission from the discs, and a digital timer controlling both the heating time of the heater and the counting time of the counting equipment, is described. The heater includes a pair of power amplifiers arranged in push-pull configuration. A stabilised power supply is provided, with overload protection for the amplifiers, together with a control circuit arranged to maintain the power outputs of the amplifiers at a predetermined adjustable level. A variable frequency oscillator may be provided, together with driver stages for the amplifiers. (U.K.)

[en] The report describes the preamplifiers which have been developed specifically to process the signals from the vacuum photo-triodes used on the OPAL experiment at CERN. It outlines the design philosophy, describes the chosen circuit arrangement and includes performance test data. It includes details of the surface mount manufacturing process used for the 2264 production amplifiers, and describes the automated acceptance testing system used to individually check their performance. (author)

[en] The amplifier described consists of a charge sensitive pre-amplifier optimised for low noise with low values of input shunt capacitance, and a shaping amplifier providing both differentiation and integration. Amplifier gain is adjustable up to a maximum of approximately 100 μV/electron with a rise time of 2 μS to the peak of the output voltage, and with an open circuit input noise level of 150 electrons RMS. (author)

[en] A gamma-ray detector comprises a scintillation crystal (e.g. BaF₂), a gas for converting u.v. radiation generated by the crystal into electric charge carriers and a detector to detect the charge carriers, a gap being provided between the scintillation means and the detector which contains a gate electrode to inhibit the passage of charge carriers. There are also a pair of amplifying gaps to enhance the electron yield of the gas. A further reverse-biased gap may be positioned adjacent to the crystal to prevent charge build-up thereon. Shield electrodes prevent gate switching signals causing spurious responses in the detector circuit. (author)

[en] Using the fast neutron flux available from the beam collector on the RAL spallation neutron source (ISIS) we have irradiated the two types of avalanche photodiodes (APD) {Hamamatsu S5345 (high capacitance) and the EG and G C30626E} up to a maximum fluence of 2 x 10¹³ neutrons per cm². We report the recovery behaviour of the device dark currents and noise characteristics following exposure to the neutron flux. Using the parameters derived from these observations we model the evolution of the dark current and noise through likely CMS activity schedules. (author)

[en] Using the fast neutron flux available from the beam collector on the RAL spallation neutron source (ISIS) we have irradiated two types of avalanche photoiodes (APD) {Hamamatsu S5345 (high capacitance) and the EG and G C30626E} up to a maximum fluence of 2x10¹³ neutrons per cm². We report the behaviour of the device dark currents and noise characteristics through the course of the exposure to the neutron flux. (Author)

[en] The PAG 438 charge sensitive anode signal pre-amplifier which is specifically designed for use in imaging MWPC applications is described. It provides a fast trigger with a sensitivity of 5 x 10⁴ e^- and a double pulse capability of 40 ns, along with a baseline restored analogue output suitable for pulse height selection at rates approaching 1 MHz. (author)

[en] In the course of calibrating a large number of avalanche photodiodes for the 1995 ECAL beam tests we noted a surprising spread in the apparent gains of the devices. We report that this effect seems to be due to charge storage in the devices causing a variable ballistic deficit in our pulse-shaping circuit. (author)

[en] This report describes a pre-amplifier specifically designed for use with artificial delay lines in positional readout systems for multiwire proportional detectors. The pre-amplifier provides an active delay line termination which gives reduced noise compared with simple resistive termination whilst maintaining the signal rise-time to allow optimum timing discriminator performance. Test results show a significant improvement in resolution compared with resistive terminated systems