Detection device UDPN-06 is intended for monitoring of density of thermal neutron flux in the channels of ionization chambers at reactor plant operation in the source range and/or during refueling.
UDPN-06 ensures the monitoring of thermal neutron flux density in IC channels within the range from 5.0·10-2 to 1.0·104 cm-2·s-1 (neutr.·(cm2·s)-1) at the dose rate of background gamma-radiation absorbed in the air at the place of detection unit location of not more than 10 Gy·h-1 (1·103 R·h-1).
UDPN-06 sensitivity for thermal neutrons is (8.0 ± 1.2) cm2 (pulse·cm2/neutr) at discrimination threshold equal to +(600 ± 10) mV, being set in conversion unit.
Detection device UDPN-06 consists of:
- Detection unit CPNB44/S15 (CPNB44/M20), implemented in the form of casing (thin-wall cylinder made of aluminum), inside which a neutron counter is located. Detection unit converts neutron radiation into current pulses.
The appearance of detection unit CPNB44/S15 is presented on the picture:
- Conversion unit BPH-05 implemented in the form of flat housing, inside of which electromagnetic shield with electronic modules is located. BPH-05 is intended for conversion of current pulses from detection unit into succession of voltage pulses which frequency is proportional to density of neutron flux.
The appearance of conversion unit BPH-05 is presented on the picture:
UDPN-06 is built-up on the basis of boron neutron counter (CPNB44/M20) with thermo-radiation stable cable with magnesia insulation. Length of CPNB44/S15 cable depends on design of detection unit.