A high rate preamplifier for use with a gas proportional counter
- Daresbury Laboratory, Warrington, Cheshire WA4 4AD (United Kingdom)
In the development of detectors for use with synchrotron radiation, a serious limit to the maximum counting rate is frequently determined by the signal processing speed of the general purpose commercial electronic units that are often used. Therefore, in developing a high speed gas proportional counter for soft x-ray spectroscopy measurements, a major requirement has been for a high rate, low noise preamplifier. A crucial factor in meeting the required processing speed is the ability to separate out the fast electron pulse from the much slower, induced ion afterpulse and to reject the latter. In addition, all gas proportional counters suffer from occasional high voltage breakdown and so the circuit design must provide the sensitive front end of the preamplifier with sufficient transient protection. We present a design for a preamplifier circuit which offers a 30 MHz bandwidth and better than 2500 electrons rms noise. It features pulse shaping which permits the complete rejection of the ion afterpulse and an input protection circuit which has enabled the preamplifier to survive detector breakdown. The preamplifier has a measured gain of 0.6 {mu}V per electron. The fast rise time of the preamplifier has allowed us to investigate the speed of the detector, a primary limitation of which is due to the electron diffusion rate within the counter. We describe an experiment conducted using this preamplifier to reduce the electron drift speed to {lt}100 ns.
- OSTI ID:
- 5519506
- Journal Information:
- Review of Scientific Instruments; (United States), Vol. 63:1; ISSN 0034-6748
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
PROPORTIONAL COUNTERS
PREAMPLIFIERS
COUNTING RATES
GAIN
PERFORMANCE
SIGNAL-TO-NOISE RATIO
SYNCHROTRON RADIATION
AMPLIFICATION
AMPLIFIERS
BREMSSTRAHLUNG
ELECTROMAGNETIC RADIATION
ELECTRONIC EQUIPMENT
EQUIPMENT
MEASURING INSTRUMENTS
RADIATION DETECTORS
RADIATIONS
440104* - Radiation Instrumentation- High Energy Physics Instrumentation