Thick Silicon Detectors Research Articles

A Thick and Large Active Area Si(Li) Detector

A 5 inch diameter, 3mm thick silicon detector has been fabricated using a nondetector grade crystal. The detector characteristics of the silicon detector were examined with infrared light as well as a hadron beam.

The Development and Testing of a Silicon Trigger Detector with 400 Elements for the Helios (NA 34) Experiment

A 30 mm diameter, 300 μm thick silicon detector has been constructed for the basic trigger element in the NA34 (HELIOS) experiment at CERN. It contains 400 discrete active junction detectors ("pads") which are connected to 400 low-noise hybrid preamplifiers giving 500 - 700 rms electrons noise level. Results of tests in spatially well-defined particle beams will be presented which verify the efficiency of each pad and its effective charge collection area.

Differences in the energy responses of thick silicon detectors for protons and alpha-particles

A systematic deviation of 0.68±0.13% has been observed between the known energy of incident protons and the value measured in a thick Si(Li) detector calibrated with γ-particles, the measured value being too low. For a secomd detector, a triple peaking effect has been observed in the detection of mono-energetic protons, while the response is normal for incident α-particles.

A technique for correction of pulse heights from thick silicon particle detectors

When detecting protons with thick silicon detectors, it is sometimes desirable to use short pulse-shaping time constants in the associated amplifier. As the charge collection time varies for electrons and holes along the proton track, an energy dependent signal loss is observed when pulse shaping and charge collection times are comparable. A method for calculating the resulting nonlinearities in the proton energy scale is presented and corrections applied to the energy calibration are compared with experiment.

The manufacture of thick lithium-drifted silicon detectors

A method is described which is used in the manufacture of thick lithium-drifted silicon radiation detectors for use in nuclear physics experiments at the University of Colorado cyclotron laboratory. An effort has been made to simplify and reduce in number the usual procedures of detector manufacture. The counters which are produced by this method are operated either at room temperature or at dry ice temperature and are of a quality comparable to that of the best detectors available.

Effective Charge Carrier Lifetime in Silicon p-i-n Junction Detectors

An estimate of the effective charge carrier lifetime can be obtained from a determination of the collection efficiency as a function of the transit time for charge carriers produced by incident short-range radiation in a p-i-n junction detector. The results of this method have the advantage of being independent of both the charge carrier mobility and the depletion depth of the detector. Effective lifetimes as low as a few microseconds (?e) for electrons produced by natural alpha particles have been observed in several 2 mm thick lithium-compensated silicon detectors operating at room temperature. No significant bias dependent windows which might cause misleading interpretation of the results were observed. Window effects were investigated by measuring the changes in pulse height of detector output signals initiated by natural alpha particles incident on the detectors at angles up to 45 degrees. The electron lifetimes were observed to decrease when the detector was operated at liquid nitrogen temperature. The short effective lifetimes that can occur in lithium-compensated silicon set a lower limit on the field strengths that must be maintained for efficient charge collection in thick p-i-n junction detectors. Effective hole lifetimes can also be obtained using this technique but with the present geometry of lithium-compensated silicon detectors this measurement is more difficult if short-range particles are used. The effects of charge carrier lifetime and amplifier pulse rise and fall times on the observed radiation-induced pulse shapes are discussed.