Understanding Neutron Radiography Post Exam Reading VIII-Part 2a of 2A

Radiation Detection Systems
Some forms of radiation, such as light and heat, can be detected by human
sense organs; ionizing radiation, however, can be detected only by the after
effect of itsionizing properties. If ionizing radiation does not interact with
matter, its detection and measurement is impossible. For this reason, the
detection process uses substances that respond to radiation, as part of a
system for measuring the extent of that response. The ionization process
isused by a large class of detection systems, including:
■ ion chambers,
■ proportional chambers,
■ geiger-müller counters and
■ semiconductor devices (Table 1).
■ Some systems depend on the excitation and molecular dissociation
( 分 子 离 解 ) that occur with ionization. These processes are useful in (1)
scintillation counters and (2) chemical dosimeters. Although other types of
detection systems exist, they are not generally used in radiation survey
instruments.
Charlie Chong/ Fion Zhang