Study On Temperature Dependence Of Dark Matter Particles Explorer Plastic Scintillator Detector

Research topics on the dark matter and dark energy have become one of the most popular topics in today world.The Dark Matter Particles Explorer(DAMPE),which belongs to the Chinese Academic of Science,has launched already.Related data acquired from the orbit detection have been being transmitted to the earth.The scientific goals of DAMPE is to detect the high energetic electrons and gamma rays with energy ranging from 5Ge V to 10 Te V.Through this trying to find out the signs of dark matter particles.When the payloads of DAMPE working in the orbital environment,they are acquired to operate effectively at the temperature between-10? to 30?,so it is necessary to study the temperature dependence of each payload belonging to the DAMPE.The Plastic Scintillator Detector Array(PSD)is one of the payloads of DAMPE,which is developed by the Institute of Modern Physics,Chinese Academy of Science.This thesis mainly described the study on the temperature dependence of PSD.The detective modules of PSD are composed of 82 plastic scintillator bars,each bar is coupled with one photomultiplier tube(PMT)on both tips.The signals from PMT will be fed into Front End Electronics(FEE).By studying the temperature dependence of plastic scintillator bars,PMTs and FEE,the temperature coefficient of PSD could,thus,be obtained.In chapter four of this thesis,the experiment for studying the temperature dependence of the plastic scintillator bar,the PMT and the FEE respectively were carried out.The temperature coefficient of the PMT obtained in this experiment is-0.320(±0.032)%/?,compared with the scintillator bar with the coefficient of-0.037(±0.042)%/?.The temperature coefficient of FEE,which could be tested aparted from PMT and scintillator system is-0.385(±0.013)/?.According to the results above,we can see that the contribution of PMT is dominated in the temperature coefficient of PMT-scintillator bar system.Since the contribution of each part to total temperature coefficient of scintillator-PMT-FEE system has been figured out,the correction works,thus,could be finished.However,because of the difference of each single PMT,in order to obtain the coefficient that could be use directly to correct the data from PSD,in chapter five,the experiment on studying the temperature dependence of PSD was carried out.Then we used the coefficients obtained by the experiment to correct the PSD data collected when the operating temperature is various.The correction results turn out to be ideal.There is little discrepancy when comparing the corrected data with the data collected at stable temperature environment.The study on the temperature dependence of PSD make us acquire the temperature coefficient of every channel in PSD which is basis for correcting the orbital data to erase temperature effect and thus obtain a better energetic spectra resolution.