Development of self-powered neutron detectors used in nuclear medicine for the measurement of neutron flows during treatment of boron neutron therapy

Purpose The Self Powered Neutrons Detectors(SPND)have the advantage of not requiring a high voltage power supply for their operation and are small in size,enhancing the interest of these detectors in medicine.Methods In this context,we have developed a thermal neutron detection system based on SPND.This detector was placed in the thermal channel of our nuclear research reactor;where the values of the current for each detector have been recorded as a function of time,with a chain in a current mode where electrometers without HV were used.Results We performed the real-time measurement of neutron flux during boron neutron capture therapy or boron neutron therapy,the different materials constituting the SPND detectors have been carefully chosen for this application.These detectors were tested at a power of four MW corresponding to a neutron flux of 10^(9) n cm^(−2) s^(−1).Conclusions The usefulness of 103Rh-SPND is for online measurement of thermal neutron flux on BNCT patients has been demonstrated based on an appropriate calibration of the thermal neutron spectrum.

^(3)He proportional counter development for thermal neutron detection

Neutron detection is used in a wide range of applications in nuclear physics,radiation protection,nuclear fuel cycle,reactor instrumentation,security and industrial measurement.Among the detectors used in this field,we notice the gas-filled 3He proportional counters which have been one of the main detecting tools for thermal and cold neutron detection for many years.This last characteristic has ensured that this detector is one of the best tools for thermal neutron flux measurements in a nuclear reactor control.In the instrumentation and detection laboratory of the Nuclear Research Center,of Birine,we are working toward the design and the development of this type of detectors,indeed,several prototypes of neutron detectors have been realized including the 3He proportional counters.Through this paper,we will present the experimental steps and the obtained results to carry out a 3He proportional counter prototype that was fully developed and tested in our laboratory.A comparison study was made between our detector and a commercial cylindrical 3He neutron detector which was considered in this work as a reference detector:LND252(3He)-PC.The results showed that the characteristics of the gas amplification and the counting plateau for the two counters reference LND 252(3He)-PC and our prototype was of the same order of scale.The experimental tests show that our developed prototype perfect fit with the standard International Electrotechnical Commission(IEC,www.iec.ch)in the operating principle,the technology adopted and obtained technical specifications.

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 25μm.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(CH410%)),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.