The Research Of Electronic System Of Key Parameters Measurement For BNCT Physical Dosimetry

Cancer is a serious threat to people’s health,and the number of cases is showing a rising trend.Effective cancer treatment plan is very important.At present,radiotherapy occupies a large proportion of the common methods of cancer treatment.Boron Neutron Capture Therapy(BNCT)is a type of radiotherapy.It can selectively kill cancer cells while retaining normal cells,which has advantages in the principle of treatment.As one of the main research contents of BNCT,dose measurement plays a vital role in the specific implementation of the treatment plan,which involves dosimetry-related knowledge.In BNCT dosimetry,there are many parameters that need to be measured,so as to provide’ the necessary basic data for clinical treatment.The key parameters include:neutron energy spectrum,gamma energy spectrum,neutron and gamma fluence spatial distribution,neutron and gamma absorbed dose rate.Regarding the measurement of these key parameters in the BNCT radiation field,there is currently no international standard method,and only specific selections can be made according to the actual situation.On the basis of investigating the measurement methods of various parameters,this paper further introduces the key parameter measurement devices used in this subject,and according to the characteristics and measurement requirements of these measuring devices,a series of requirements are put forward for the development of electronic systems.After analysis and research,this paper divides the functional modules of the electronic system into:data acquisition module,power supply module,electrometer module and diamond detector preamplifier module.Among them,the diamond detector pre-amplification module is responsible for proportionally converting the charge signal output by the diamond detector into a voltage pulse signal,which is convenient for subsequent measurement.The data acquisition module is responsible for analog conditioning of the input signal and acquisition and acquisition through analog to digital converter(ADC),and then the data is processed and read out through the algorithm logic in the Field Programmable Gate Array(FPGA).The power module is responsible for providing the necessary working voltage for the detector and its preamplifier.The electrometer module is responsible for reading the weak current signal.In order to derive the design requirements of each functional module and guide the development of electronic systems,this thesis conducts a detailed analysis and research on the signal characteristics and measurement requirements of the measurement electronics system for the key parameters of BNCT physical dosimetry,and proposed the electronic system design scheme based on PXI Express(PXIe)platform.Except for the preamplifier module placed near the detector,the other modules are all designed in the form of PXIe plug-in cards,which greatly improves the integration,scalability,availability and maintainability of the system.Based on the overall scheme of the modular electronics system,this article further introduces the detailed design of each electronics module.In order to verify the performance of the electronics module and the performance of the entire electronics system,the paper tested and verified each module under laboratory conditions,and the results showed that each module can work normally and perform well.