K. Andert

Timing system for Ge(Li) detectors

Abstract A timing system for coincidence and nuclear lifetime measurements with Ge(Li) detectors is described. The timing discriminator, based on the ARC-principle, is designed using integrated circuits. Uncompensated pulses from low energy events near the threshold of the timing discriminator are eliminated by a special internal coincidence circuit. Output pulses caused by noise, are excluded by duration discrimination. The detector signals are amplified by a preamplifier and a fast amplifier with 2.5 and 3.5 ns risetimes, respectively. The time resolution has been obtained 15.6, 2.7 and 1.1 ns fwhm for energies 50, 511 and 1330 keV, respectively, by using a planar detector (1.9 cm 3 ) with a collection time of 40 ns. The differential peak shift in the range from 10 to 1330 keV was 1.2 ns.

Timing System for Ge(Li)-Detectors

A timing system for coincidence and nuclear lifetime measurements with Ge(Li)-detectors is described. The timing discriminator, based on the ARC-principle, is designed using integrated circuits. Uncompensated pulses from low energy events near the threshold of the timing discriminator are eliminated by a special internal coincidence circuit. Output pulses caused by noise, are excluded by duration discrimination. The detector signals are amplified by a preamplifier and a fast amplifier with 2.5 and 3.5 nsec risetimes,respectively. The time resolution has been obtained 15.6 , 2.7 and 1.1 nsec FWHM for energies 50, 511 and 1330 keV, respectively, by using of a planar detector (1.9 cm3) with a charge collection time of 40 nsec. The differential peak shift in a range from 10 to 1330 keV was 1.2 nsec.

A CAMAC-matrix for distributing fast logic signals

Abstract Construction and parameters of a CAMAC-module for fast logic signals are described. This unit allows a computer-controlled connection of its eight inputs with its eight outputs in any possible combination. Examples of application of the CAMAC-matrix in the field of high energy and nuclear physics are given.

Logarithmic digital-analog conversion for varying parameters in Camac devices

Abstract Some methods of digital-analog conversion, necessary for a series of devices in the Camac system with analog functions, are discussed. A logarithmic method which allows to perform conversion in a very large range (1:10 4 and larger) with a high stability (about 10 −4 /°C) is considered.

A universal CAMAC coincidence circuit

Abstract A universal CAMAC-coincidence circuit is described. All basic parameters are controlled in a wide range from the CAMAC- dataway: the coincidence resolving time (2τ) from 1 ns to 10 μs and the anticoincidence resolving time from 10 ns to 10 μs.

A universal CAMAC pulse shaper

Abstract A highly stable CAMAC pulse shaper is described. The pulse length is controlled from the CAMAC-dataway and can be changed in steps of about 3.5% from 20 ns to 150 μs. This single-width module operators in two modes: the “normal” mode and the “updating” one. The double pulse resolution of the “updating” mode is 20 ns.

Timing in fission fragment detection at high alpha-background

Abstract The ionisation multiplate fission chamber working together with a fast low-noise level preamplifier, is described. Fission fragments were registered with an efficiency of about 50% at a background of 10 8 α/s. The timing characteristics are illustrated by the time distributions of fission events measured at the μ − beam of 680 MeV synchrocyclotron, JINR Dubna.