Research On Two-Phase Argon TPC Detector Applied To Detect Coherent Scattering Of Reactor Neutrino

The reaction cross-section of the neutrino-nucleon elastic coherent scattering process is directly proportional to the square of the number of neutrons in a nucleus.For heavy nuclear target material,neutrino-nucleon coherent scattering has a larger reaction cross-section,so it is possible to obtain more efficient neutrino detection by using coherent scattering.The process of detecting neutrino-nucleon coherent scattering is of great scientific significance in nuclear physics,astrophysics,cosmology,and so on.Additionally,the process of detecting neutrino-nucleon coherent scattering has its application value in nuclear reactor monitoring and opens a channel for the engineering application of reactor neutrinos.The two-phase argon time projection chamber detector is an important hardware alternative for this detection technology due to its excellent spatial resolution,low detection threshold,and easy expansion of liquid volume.Therefore,relying on the subject objectives,this paper mainly completes the research and development of the prototype of the two-phase argon TPC detector which can be applied to the near point neutrino-nucleon coherent scattering detection of the reactor,debugging the stable operation of the detector,calibrating the prototype detector and conducting experimental rehearsal by using radioactive sources.Based on the working mechanism of the two-phase argon TPC detector,the design and manufacturing process of the prototype of the two-phase argon TPC detector,as well as the optimization results of the related technology of the detector are introduced.First,the effects of the thickness of TPB film on the light transmittance and reflectivity of the coated fused quartz glass were studied,and the optimal coating thickness of 105μg/cm2 was obtained.Second,according to the principle of the two-phase argon TPC detector,the electric field of the detector was simulated,and the suitable design scheme of the spindle-like field cage electrode and the reasonable electrostatic field distribution of the detector were obtained.Combined with the electric field simulation results,experimental experience,and optimization ideas,the overall structural design of the new two-phase argon TPC detector is completed.Third,the calibration of different concentrations of xenon and argon doped gas mixture components was completed,and the linear relationship of the calibration method for the content of xenon in the xenon and argon doped gas was obtained,with a linear correlation coefficient R2=0.9998.This paper introduces the process of setting up the operating platform of the detector and completes the calibration of the new two-phase argon TPC detector.The operation platform of the two-phase argon TPC detector and the filling process of liquid argon are described in detail.A total of 3 1.8kg of liquid argon was injected into the system and the system runs stably at 89.7±0.3K.In terms of detector calibration,the single photoelectron calibration of the Hamamatsu R11065 photomultiplier tube used in the experiment wass completed,and the waveform peak searching method of the detector was studied.The calibration process of the detector with 241 Am and 22Na radiation sources is introduced.The light yield of the detector is 7.43 pE/keV,and the energy resolution of the detector is 7.80%.In addition,the S2 signal amplification ratio of the detector is studied under different electric field configurations,and the S2 signal amplification ratio of the argon layer is 19.92.Finally,the effects of electric field configuration respectively on the light yield of liquid argon luminescence(Ly)and the corresponding electricity yield of gas-phase luminescence(Qy)are calibrated.