The Monitor

The monitor consists of a modularized discriminator, logarithmic integrator, level amplifier, period amplifier, and chamber polarizing voltage supply. In addition, there are trip circuits, power supplies, and filters. Modules are mounted in the chassis. These modules function as follows:

a. The discriminator comprises an input common base stage for cable termination, an integral pulse height discriminator, a shaper, a binary, and a driver.

b. The logarithmic-integrator is a passive integrator of the Cooke-Yarborough type. The breakpoints of the networks are spaced one decade apart. The time constant over the range is a function of the point on the range and follows a smooth curve. The analytic

, expression for the analog out is:

Vn (TP1) = — [ Log (count rate) + 1 ]

7 .

6-1

c. The level amplifier is a d-c amplifier which has a current gain of approximately 3. 5 amps/amp.

d. The period amplifier is a d-c amplifier with appropriate feedback components to provide a gain of approximately 200 volt/volt/sec. This corresponds to a full-scale period indication of 10 seconds.

e. The trip circuits are d-c difference amplifiers with two-state outputs.

f. The chamber polarizing voltage supply is a d-c to d-c converter which provides + 100 to +400 volts d-c to polarize the detector.