Hand-held Spectrometer based on High-Purity Germanium Coaxial Detector

NitroSPEC

1. APLICATION

The NitroSPEC is intended for Gamma and X-radiation registration and analysis used in the radiological control of environmental objects, materials and products of industry and farming, ob-jects of nuclear industry enterprises dealing with storage and processing of radioactive wastes.

The NitroSPEC is the world's smallest liquid nitrogen cooled Spectrometer which consists of HPGe detector, Dewar vessel for liquid nitrogen, MCA with software package and visualization monitor integrated in one miniature monounit to provide easy and comfortable use.

2. FEATURES

All in one solution; Minimal sizes and weight; Ready for operation in short time; Long autonomous operational time; Simple and cheap in maintenance and service.

3. COMPLETE SET

HPGe coaxial detector GCD-10180 with preamplifier and Dewar vessel; Built-in Digital 16K Multi Channel Analyzer; Analytical software package; Touch screen display; Built-in GPS module; Communication interface (USB, wireless); Removable Tungsten alloy collimators. Documentation set in English; Accessories:

Head Management:Dr. Gostilo VladimirDr. Sokolov AlexanderMr. Moshak Vladimir

Bank details:Nordea Bank Finland PLC Latvia branchBank code: NDEALV2XIBAN account: LV13 NDEA00000802 26011

Commercial registration number: 40003176361VAT Registration No. LV40003176361Place of registration: Riga, Latvia

o Spare battery;o Adaptor for charging;o Funnel for liquid nitrogen filling;o Hard-sided transport case;

4. TECHNICAL CHARACTERISTICS

4.1 Technical characteristics of spectrometer

№ Parameters name Value

1.Detector dimensions:

diameter, mm thickness, mm

5025

2.Relative efficiency (with respect to 3 x 3 NaI detector and Co-60 source mounted 25 cm above the detector) at 1.33 MeV g-photon

≥ 10%

3.

Energy resolution* for energy 122 keV, eV for energy 1.33 MeV, eV

*shaping time constant τ= 6 s, measurements with MCA 527 at input count rate 1000 cps

≤ 825≤ 1800

4.Peak shape

FWTM/FWHM FW.02M/FWHM

≤ 1.9≤ 2.65

5. Energy range of detector operation 40 keV – 3 MeV6. Cooling time ≤ 1.5 hours7. Dewar vessel volume 0.6 l8. Battery operation time ~ 8 hours9. Autonomous operation time at filled Dewar ≥ 20 hours

10.Touch screen

Resolution, pixels Diagonal, cm

800x40010.8

11. Overall dimensions, mm 154 × 324 × 21712. Weight ~ 5 kg13. The range of the operating temperatures ,° С from 0 to +4014. Preamplifier with resistive feed back with cooled FET.15. Preamplifier power ±12V with 9 pin connectors compatible with NIM standards.

16.Alarm signal to shut down the HV:

detector warm -0V; detector cold +5V.

4.2 Built-in digital spectrometric device technical characteristics

Amplifier Coarse amplifier pre-filter with amplification in steps of 2-5-10-20-50, corresponding to a

full scale; ADC input range from 12V to 500mV; Input DC coupled, offset adjustable and depending on polarity of input signal; Linearity is better than 0.1 %.

ADC 14bit, 10 MSps;

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Integral nonlinearity is better than 0.05 %; Temperature stability TK 50.

Digital signal processing Double differential trigger filter, or single differential low energy low count rate trigger filter; Pile-up-suppression, pulse pair resolution ~ 400 ns, depending on trigger filter; Automatic and manual adjustment of trigger threshold; Shaping time (Integration time / rise time of filter divided by 2) adjustable in the range 0.1 –

25 µs; Flat top adjustable 0 – 5 µs; Fine adjustment of amplification in steps of ≤ 0.05 %; Channel splitting 128, 256, 512, 1k, 2k, 4k, 8k and16k; Differential non-linearity ≤ 1% for 4k channels and 1 µs shaping time; Base Line restorer with adjustable averaging; Optimum spectroscopic performance for 50 µs preamp decay time constant; PZC adjustment, detector decay time constants from 40µs to 1 ms can be compensated.

4.3 Basic Spectrometry software

In search mode of operation a measurement of continuous spectrum is happening upon push-ing a single button, information is updated every second. Dose rate is calculated from integral spec-trum and is visualized on a display in μSv/h. In case of excess of dose rate over user defined thresh-old instrument produce visual and acoustic alarm. Energy calibration is available from a touch screen. Identification of radionuclides is performed according to library of radionuclides automati-cally. List of identified radionuclides and corresponding count rates with background deduction ap-pears on the screen. Depending on the categories each identified radionuclide is marked by different index and color:

Natural radionuclides are marked by N index, for example Th-232…N, and have green color; Industrial radionuclides are marked by I index, for example Co-60…I, and have blue color; Radionuclides used in medicine are marked by M index, for example F-18…M, and have red

color; Illicit trafficking radionuclides are marked by UPu index, for example Am-241…UPu, and

have black color; Other radionuclides are not marked, for example Eu-152, and have grey-50% color.

In advanced mode of operation user can select regions of interest in the spectrum or ratios of regions of interests and could calculate corresponding areas or ratios of areas.

Energy calibration of NitroSPEC spectrometer, automatic radionuclides identification with corresponding count rates and ROIs selection could be performed using touch screen.

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Fig.1. Operating window screen shot.

4.4 SpectraLineGP analytical gamma spectrometry software

The NitroSPEC could be easily connected to Laptop via wireless or wired communication for operation with SpectaLineGP software for analysis of spectra, identification of radionuclides and determination of their activities by commonly used methods.

Software functions:

Automatic peaks search with the required sensitivity level; Energy, and peak shape calibration; Peaks parameters determination — position, FWHM, area; Automatic radionuclides identification; Registration efficiency curves creation and radionuclides activities calculation; Saving of the measured spectra and processing results to database; Repeated measurements analysis; Simultaneous processing of several spectra, using several spectrum peaks from different

energy intervals for the calibration by peaks shape; Calibration control by values and visually; User processing scenarios; Interactive processing of spectra intervals; Library of radionuclides; User-friendly interface.

4.5 Tungsten alloy collimators

Tungsten alloy is the composite of tungsten (90%), nickel (6%) and copper (4%). Collimation set represents a cup made from Tungsten alloy lined with 1.5 mm Cu mounted on the detection unit end cup. Internal diameter of cup is 64 mm. Cup has front window with diameter of 40 mm. Four re-movable collimators of same composition and thickness as a cup could be easily screwed up into cup. Collimators have windows with diameters of 5, 10, 15 and 25 mm. Thickness of cup walls is 7 mm.

Collimators are used for U enrichment measurements in UF6 cylinders.

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