Detection device UDPN-03 is intended for monitoring of thermal neutron flux density in the channels of ionization chambers at reactor plant operation in the source range or during refueling.
UDPN-03 ensures the monitoring of thermal neutron flux density within the range from 4.0·10-2 to 4.0·103 cm-2·s-1 (neutr.·(cm2·s)-1) at the dose rate of background gamma-radiation absorbed in the air equal to 1.0 Gy·h-1 (1.0·102 R·h-1).
UDPN-03 sensitivity for thermal neutrons is (5.0 ± 0.5) cm2 (pulses during 1 s at the flux density of 1 neutron via 1 cm2 during 1 s).
Detection device UDPN-03 consists of:
- Detection unit BDPN-03, implemented in the form of casing (thin-wall cylinder). BDPN-03 converts neutron radiation into current pulses.
- Conversion unit BPH-03, implemented in the form of flat housing, inside of which the electromagnetic shield with electronic modules is located. BPH-03 performs the following:
- amplification of current pulses from BDPN-03;
- discrimination of noise pulses;
- generation of output pulses which frequency is proportional to neutron flux density.
UDPN-03 is built-up on the basis of proportional neutron counters SNM11 with radiofrequency flexible cable KAGE-HF. Length of BDPN-03 cable is 14 meters.