/ Nuclear radiation spectrometers

PURPOSE                     The spectrometer is intended to determine the isotope composition of radioactive materials, activity of bare sources and radionuclides in packing sets, enrichment of uranium compounds in transport containers, gamma dose rate, as well as to carry out qualitative and quantitative analysis of various items for presence of gamma-emitting radionuclides under both laboratory and harsh field conditions. APPLICATION By customs offices to control legally transported radioactive and fissionable materials (RFM) with the known isotope composition or illegally transported RFM with the unknown isotope composition, which may be done without opening the shipping containers; By external radiation dosimetry services to carry out radiation control of territories adjacent to radiation-hazardous installations, such as NPPs, nuclear cycle facilities, military installations, etc; By environmental services of various ministries and departments to test various items for contamination with gamma-emitting radionuclides, also on the mobile basis (mobile radiological laboratories); By radio chemical laboratories for monitoring of technological processes; In other areas of science and technology where nuclear-physics methods of analysis are used. DESIGN MODIFICATIONS The spectrometer can come in two design modifications: Gamma-1S/NB1-01 uses a NaI(Tl) crystal based detector; Gamma-1S/NB1-02 uses a LaBr3(Ce) crystal based detector.           Gamma-1S/NB1-01 uses the UDS-GCA-40x40-RS (or UDS-GCA-40x40-RS-ВТ1*) stand-alone gamma scintillation digital detecting device, which is based on a Ø40x40 mm NaI(Tl) crystal.           Gamma-1S/NB1-02 uses the UDS-GCA-B380-38x38-RS (or UDS-GCA-B380-38x38-RS-ВТ1* gamma scintillation digital detectingdevice, which is based on a Ø38x38 mm LaBr3(Ce) crystal.           LaBr3(Ce) crystal based detecting devices feature better resolution when compared with NaI(Tl) based devices. Application of such devices in the spectrometer make it possible to identify radionuclides at less statistics.           LaBr3(Ce) crystals exhibit higher density than NaI(Tl) crystals, which leads to a better efficiency of LaBr3(Ce)-based devices when compared with NaI(Tl)-based devices. For low energies (~100 keV) the devices exhibit similar efficiency, yet for higher energies (~2.5 MeV) LaBr3(Ce) based devices provide a one and a half times better efficiency.           Application of LaBr3(Ce)-based detecting devices decreases time for measurement of samples and increases accuracy of determination of their activity.           * Note: "BT1" in the detecting device name indicates a feature allowing a possibility of Bluetooth connection with a computer. COMPONENTS Major components: Stand-alone gamma scintillation digital detecting device; Portable computer; SpectraLineHandy software; Additional components: Collimator with a device to carry the detector; Holder to position the detecting device in relation to the measured object; Calibration source with the holder and storage container; Carrying box. FEATURES System for stabilization of the measuring path on the basis of a special LED with amplification temperature correction feature; Digital processing of signal; Connection of the detecting device with a computer via RS, USB or Bluetooth interfaces; Power supply from AC or embedded batteries; Extended temperature range; The detecting device diameter allows application of a standard Marinelli vessel as a measurement geometry. FUNCTIONS Software allows the spectrometer to operate in the following modes: Management of the measuring path parameters; Management of information accumulation with exposure by time; Visualization of acquired information on a computer display; Energy, half-width, peak shape calibration; Efficiency calibration and generation of approximating curves; Calculation of activity by different methods; Performance of multiple measurements and their analysis; Determination of isotope composition of gamma-emitting radionuclides; Determination of bare sources activities in the given geometries; Determination of sources activity in package sets [containers); Determination of specific activity in long objects; Determination of degree of uranium enrichment; Determination of gamma radiation dose rate; Storage of spectra and processing results in the database. SPECIFICATIONS Parameters Gamma-1S/NB1-01 Gamma-1S/NB1-02 Range of detected gamma energies, MeV 0.05 to 3.0 or 0.05 to 2.0 Energy resolution of the spectrometer for the 662-keV gamma line (137Cs), %, not exceeding 8 3.5 (typical value is — 2.8…2.9) Efficiency of registration of gamma quanta with energy 662 keV (137Cs), at the source-detector distance of 25 cm, %, not less than 0.03 0.035 Number of channels used by the spectrometer 1024 Limits of integral non-linearity within the range of detected energies, % ±1 (typical value is  ±0.3) Time instability for 24 h of continuous operation, %, not exceeding 1 Maximum input statistic intensity of the spectrometer, cps, not less than 1.5•105 2.5•105 Period of operating mode setup, min, not exceeding 20 Period of continuous operation on battery, h, not less than 10 Period of continuous operation from 220V AC line not limited Range of activity measurement for Cesium-137 (137Cs), radionuclide, Bq 8* to 1•105 Limits of tolerable basic relative error of activity measurement (P=0.95), % ±(10—50) Gamma dose rate measurement range, μSv/h, at basic relative error of 20% 0,1 to 100 Range of operating temperatures, оС –20 to +50 * Note: Lower limit  of measured activity range (i.e. minimum measured activity) is given for measurement time of 1 hour with application of a collimator. OVERALL DIMENSIONS AND WEIGHT OF THE MAIN COMPONENTS Name Overall dimensions, mm, not exceeding Weight, kg, not exceeding Stand-alone gamma scintillation digital detecting device Ø79x376 1.6 Collimator in assembly 146x250x215 12 Holder Height is 1.3 m 2 Carrying case 470x355x170 1

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