Logarithmic charge amplifier for scintillation detectors

Journal Article · Mon Jan 01 04:00:00 EST 1973 · Nucl. Instrum. Methods, v. 113, no. 3, pp. 401-412

DOI:https://doi.org/10.1016/0029-554X(73)90506-5· OSTI ID:4394699

Radeka, V

A logarithmic system is described in which a new fast logarithmic converter is employed. An accurate logarithmic response over five decades has been achieved with this system. Operating conditions of the photomultiplier are optimized so as to achieve a large dynamic range with linear response. The fast logarithmic converter is a current-to-voltage converter based on the exponertial dependence of the collector current on the base-emitter voltage of the bipolar transistor. High speed is achieved by a circuit configuration which employs a transconductance amplifier instead of a conventional operational amplifier. The signal charge is measured indirectly by measuring the current discharged from the capacitance of the anode of the photomultiplier into the logarithmic current amplifier. The rise time is standardized for the whole dynamic range to about 0.3 mu -sec by using an R-C-R-Tnetwork between the anode of the photomultiplier and the input of the logarithmic amplifier. The recovery time is determined by this network, and it is 2.4 mu sec per decade. The charge range of the amplifier is from 10/sup -14/to 3 x 10/sup -9/ C. The equivalent noise of the amplifier is less than 10/sup -15/ C. (auth)

• Research Organization: Brookhaven National Lab., Upton, NY
• Sponsoring Organization: USDOE
• NSA Number: NSA-29-010181
• OSTI ID: 4394699
• Journal Information: Nucl. Instrum. Methods, v. 113, no. 3, pp. 401-412, Journal Name: Nucl. Instrum. Methods, v. 113, no. 3, pp. 401-412; ISSN NUIMA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

*AMPLIFIERS-- ELECTRONIC CIRCUITS
*SCINTILLATION COUNTERS-- AMPLIFIERS
N46110* --Instrumentation--Radiation Detection Instruments-- General Detectors & Monitors
NOISE
PERFORMANCE
PHOTOMULTIPLIERS
PULSE CONVERTERS
SENSITIVITY