Study Of Far-ultraviolet Photon Counting Imaging Detector Based On Induced Charge Position Sensitive Anode

Aurora is generated by high-energy particles from the solar wind along theearth s magnetic field lines injecting into the high latitudes of the earth andinteracting with the main components of the atmosphere. Aurora spectral radiation infar-ultraviolet (FUV) includes HI121.6nm (Lyman-), OI130.4nm, OI135.6nm andthe LBH (Lyman-Birge-Hopfield) of N2from140nm to180nm. The intensitydistribution of N2LBH radiation can show the shape of aural ellipse area, determinethe boundary of aural ellipse area, occurrence time and location of the magneticsub-storms, also obtain radiation characteristics of solar EUV spectra through theinversion of the image. Therefore, a wide field aurora imager is developed forimaging and observing N2molecule LBH radiation intensity distribution(140nm~180nm) to obtain the relevant information of solar activity. Far-ultravioletphoton counting imaging detector is the core of the wide field aurora imager, so thispaper mainly researches on the optimization design, imaging performance test andthe calibration of the Far-ultraviolet photon counting imaging detector. The maincontents are concluded as follows:(1) Study on the components of the FUV photon counting imaging detector andtheir working principle. Analysis of the influence for the semiconductor thin film tothe performance of the photon counting imaging detector based on induced chargereadout and optimization of parameters of the semiconductor thin films. The relationship of sheet resistance of the semiconductor and the electron diffusion timewas derived according to FIck s second law and the range of the sheet resistance(30MΩ/□~2700MΩ/□) was also obtained and vertified by experiment.(2) Performance measurement and evaluation was implemented to meet theimaging requirements and optimize the performance of the detector. The gain wasalso obtained at different voltage.The resolution test, dark counts and dynamic rangewere also measured.(3) The radiation calibration of the photon counting detector was studied. Thequantum efficiency at different wavelength, different incident angle was analyzedand measured. A stable deuterium lamp was used to calibration the photon detectorto determine the relationship between the gray scale of the image and the incidentnumber of the photons changing with wavelength.(4) The image processing algorithm can improve the imaging quality of theimage. Using the blind deconvolution algorithm based on L-R to process theobtained images, the resolution was improved from0.5mm to0.4mm.