5. 1 GENERAL DESCRIPTION

The counting channel electronic subsystem is composed of the following parts: a remotely — mounted pulse amplifier, a locally-mounted monitor, a cable to connect the remote amplifier to the detector assembly (or the detector, in the case of the out-of-core system), and a set of three cables — one each for chamber polarizing voltage, signal, and power connections to the remote amplifier from the monitor.

6. 1. 1 Remote Amplifier ‘

The remote amplifier is a radio frequency pulse amplifier operating in the current ampli­fication mode. The amplifier contains the following stages: an input common base stage, a low level doublet amplifier, an attenuator, a buffer stage, a common collector amplifier stage, and. a high gain stage. These stages function in the following manner: The input common base stage provides a low input impedance for cable termination; the low level complementary doublet amplifier stage provides a current gain of approximately 40; the attenuator network provides attenuation of 1:1, 2:1, 4.1, and 8:1; the common base buffer stage acts as a buffer between low and high level stages; the common collector stage provides current gain of approximately 40 without phase inversion; and the high-gain complementary doublet provides a current gain of approximately 100. In addition to the amplification stages, the remote amplifier includes filters for the chamber polarizing voltage from the monitor and the power voltage from the monitor.