IEC 62372-2021 Nuclear instrumentation – Housed scintillators – Test methods of light output and intrinsic resolution.
4 Test methods of basic parameters of housed scintillators
4.1.1 Test conditions
Measurements shall be made under normal conditions, unless otherwise specified in the specifications of the manufacturer of housed scintillators.
Measurements should start at least 0,5 h after the last device has been switched on, unless otherwise specified by the manufacturer specifications.
Before measuring, the housed scintillator and the PMT is kept under high voltage for the time necessary for getting to the operation condition. Before measuring, the PMT is kept under high voltage for the time necessary for getting to the operation condition.
All parameters are measured during the complete blackout of the housed scintillator and PMT.
Optical contact between the housed scintillator and the PMT is provided by the material specified in the manufacturer specifications of the housed scintillator.
For the measuring, the following condition of choosing PMT should be reached: the working part of the photocathode shall overlap the output window of the scintillator.
It is allowed to apply a light guide or an assembly of several PMT, if technical characteristics and use conditions of light guide or assembly are specified in the specifications.
The measured housed scintillator is mounted on the PMT photocathode by optical contact, unless otherwise is specified in the manufacturer’s specifications.
It is allowed to place a source of ionizing radiation inside the light protective chamber.
PMT voltage should correspond to its attached data for operation conditions.
The spectrum of pulse height should be measured to define operation conditions of the assembly.
4.1.2 The sources of ionizing radiation
Enclosed radioactive sources of alpha-, beta-, gamma-, X- and neutron radiation with known energies should be used. The source of radiation shall be selected depending on the application of measured housed scintillator according to Table 1 .
For measurements with the gamma- or X-radiation sources, they should be placed along the scintillator axis at minimum distance of not less than two diameters or a diagonal of the scintillator.IEC 62372 pdf download.