Boron-10 lined proportional counter development for thermal neutron detection

Purpose Neutrons detection is of paramount importance in nuclear physics experiments, reactor physics, monitoring and control of nuclear reactors and in radiation protection. Among the neutron detectors used are Proportional Counters (PC to BF₃, boron deposition, ³He), Our Detection and Measurements laboratory has embarked on a project to develop, design and build proportional counters with boron deposition mainly for gas filling, several prototypes of which have been produced.
Method This work presents the Boron-10 Lined Proportional Counters (PC), developed and produced in the Detection and Measurements Department (DDM19). The PC was designed by adopting, for the electrodes, a stainless steel cathode 0.5 mm thick and a gold-plated tungsten anode with diameter of 25 µm. The detectors are filled with an Ar-CH₄ mixture (10%) at a pressure of 20 cmHg. The boron deposition is performed by the technique of electrophoresis.
Result The results obtained using the DDM19 prototype PC (Detector produced in our Detection and Measurement laboratory, 2019), show the advantage of electrophoresis as a better boron deposition technique, and the limitation of the surface mass of ¹⁰B to optimal values is around 0.5 at 0.6 mg/cm².
Conclusions The characteristics of the gas amplification in the mixture (Ar-CH₄ (CH₄ 10%)), were measured by different methods and compared with the values of the proportional reference counter LND232. The counting plates for the two reference meters LND232 and our DDM19 prototype from 200 to 300 V have slopes ranging from 6.5 to 10%/100 V, and gas amplification factors from 1436 to 1380, respectively.