The SEG-50(P) metrologically certified gamma-spectrometer which is based on the semiconductor germanium-lithium low-noise drift-diffusion detector DGDK-60V and covered with passive shielding made of 5 cm of lead and 0.5 cm of copper to reduce the natural gamma-radiation background is used in RREPL. The SBS-75 single circuit board analyzer and programs for spectra acquisition and analysis which were made by the RIIE “Green Star Instruments” (Moscow, Russia) are utilized in the spectrometer. The DGDK-60V detector is designed to measure the energy spectra of gamma-radiation in the energy range of 0.05 – 10 MeV.
With the aid of the spectrometer, measurements of the specific and volumetric activities of technogenic and natural radionuclides in different specimens, including:
- air filters;
- construction materials;
- food, etc.,
The energy resolution of the spectrometer at 1332 keV is 2.7 keV. The minimum activity which
can be measured in the geometry of Marinelly using a vessel with volume of 1 l per 1 hour is:
137Cs – 1,2 Bq, 226Ra – 7 Bq, 232Th – 7 Bq, 40K – 27 Bq.
To detect and do spectral analysis of gamma radiation and fluxes of charged particles, the BDBS (BDBSZ-1еМ) detecting modules are used in the laboratory. These modules have the abilities to:
- investigate alpha- and beta-active samples in the case when the sample on a substrate may not be fixed;
- measure beta- and gamma- surface contamination;
- measure weak activities of gamma-radiation emitted by liquid, solid and powdered samples.
|Type of detector||Energy||Sensitivity||Lower limit|
|0,5 – 3 MeV|
|0,5 – 3 MeV|
|1,5 – 10 MeV|
|0,1 – 2 MeV|
|0,1 – 3 MeV|
To measure the spectral content of gamma-radiation behind the shielding of accelerators, a detector based on 150×300 mm NaI(Tl) crystal and the AI-95 pulse analyzer is used. This assembly allows one to detect gamma-radiation in the energy range from 100 keV to 30 MeV with the efficiency close to 100%.