(1) Ionization Detector
Operating Principle: If nuclear radiation is absorbed by a gas in an ionization chamber, the gas will be ionized. Ionization detectors measure by collecting the ionizing charge generated by the radiation in the gas. Commonly used instruments include ionization chambers, orthogonal counting tubes, Geiger-Miller counting tubes (G-M tubes).
Scope of application: the ionization chamber is to measure the ionization current generated by ionization, suitable for measuring strong radioactivity; positive ratio counting tube and Geiger-Müller counting tube is to measure the ionization caused by each incident particle to generate a pulsed voltage change, so that the incident particles are counted one by one, suitable for the measurement of weak radioactivity.
(2) scintillation detector
Principle of operation: the use of ray irradiation in some scintillator and make it flash principle of measurement. It has a scintillator, when the ray enters it, a flash is generated, and then the photomultiplier tube amplifies the flash signal and records it.
Scope of application: used to measure the intensity of α, β, γ radiation; can be measured through the energy spectrum, identification of radionuclides, and under appropriate conditions, can quantitatively analyze the mixture of several radionuclides. In addition, this instrument can also measure irradiation and absorbed dose.
(3) semiconductor detector principle of operation: radiation can be absorbed in a solid-state semiconductor, when the radiation interacts with the semiconductor crystals will produce an electron-hole pair. Electrons and holes in the electric field under the action of the movement to the poles, generating a pulse current, amplified for recording.
Scope of application: Silicon semiconductor detectors can be used for alpha counting and determination of alpha and beta energy spectra; germanium semiconductor detectors can be used for gamma ray measurements, and have high detection efficiency and good resolution.