System for measuring the 14 MeV neutron flux by activation method
Purpose
The system is designed ti perform high precision measurements of pulse or continuous 14 MeV neutron flux from the target of neutron generators under conditions identical to those of calibration.
Features: high precision and no additional errors resulted from an effect of concomitant gamma-, X-ray, scattered and electromagnetic radiation.
Components:
- Scintillator-based detection unit;
- Measurement control;
- Set of large and small activation detectors;
- Cables;
- Clamp stands;
- Cadmium jacket;
- Software for measuring the 14 MeV neutron flux applying an activation method.
Description
The neutron flux is measured in three stages. At first stage a copper activation detector is neutron-irradiated inducing the 63Cu(n,2n)62Cu reaction. The second stage starts when the detection units and the measurement control register an induced activity from the copper detector resulted in a positron decay of 62Cu, whereupon a collected hardware spectrum is transmitted to the software on the PC. During the third stage the software on the PC calculates an average value of neutron flux for the irradiation time based on and area of the total absorption peak of annihilation 511 KeV gamma quanta on the hardware spectrum from the registered induced activity, calibration coefficient, irradiation time, exposure time and measurement time.
Metrological and Technical Characteristics
The activation system by its metrological characteristics relates to the working standard of Category 2 according to GOST 8.031
Basic metrological characteristics
| Characteristics | Value |
| Measurement range of the 14 MeV neutron flux at the solid angle of 4π sr for neutron generators using a large activation detector 64.5 mm in diameter and 10 mm thick, s-1 | from 1х107 to 1х109 |
| Measurement range of the 14 MeV neutron flux at the solid angle of 4π sr for neutron generators using a large activation detector 24.5 mm in diameter and 5 mm thick, s-1 | from 1х108 to 1х1010 |
| Limit of permissible basic relative error for measurements of the neutron flux (P=0,95), % | ±7 |
System for measurements of the 14 MeV neutron flux by activation method is include in the National Register of Measurement Equipment. Pattern Approval Certificate for Measurement Equipment OC.C.38.046.A No.75691, Reg.No.76737-19.
The measurement control is connectd to the PC via USB 2.0
The software functions in Windows XP or higher