CIRCUITRY AND CIRCUIT ELEMENTS
Radiation Detectors
where
SUR = startup rate in decades per minute
26.06 = constant
t
= reactor period in seconds
The reactor operator adjusts control rods so that an upper limit, such as 1 DPM, is not
exceeded. This allows an orderly increase in reactor power.
Summary
The source range uses a proportional counter. The intermediate range uses a compensated ion
chamber. The power range uses an uncompensated ion chamber. Terms used to describe the
electrical circuits are summarized below.
Circuit Terminology Summary
Signal-to-noise ratio is the ratio of the electrical output signal to the electrical
noise generated.
A discriminator selects the minimum pulse height to be counted.
Analog is a mechanism in which data is represented by continuously variable
physical quantities.
Logarithm is the exponent that indicates the power to which a number is raised
to produce a given number.
Reactor period is that amount of time required for neutron flux to change by a
factor of e.
Decades per minute is the rate at which neutron flux is changing by a power of
10 in each minute.
Scalar is a measurement or quantity which is capable of being represented on a
scale.
Startup rate is the rate at which neutron flux is changing measured in decades per
minute.
IC-06
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