The Electronic System Of Space Radiation Detector Of SiPM Device

With the development of space activities,higher requirements for space environment detection are proposed.The space radiation environment is the core element in the space environment.The radiation environment destroys the electronic system of the spacecraft and the intense radiation can endanger the safety of the astronauts.Detection of space radiation environment,is to observe space radiation environment and establish radiation environment model.It also ensure the normal work of the spacecraft in orbit and the safety of the astronaut.Space radiation detection not only provides technical support for the normal space activities,but also provides important means for the deep space observation of the universe.The analysis of space radiation environment includes modeling analysis and detection analysis,and the latter is a direct and reliable means to detect and analyze the radiation..Scintillator detector is one of the space radiation detectors.The electronic system of scintillator detector mainly completes the acquisition,transformation,amplification,conduction,recording and analysis of the signal.The main function of the front electronics is to complete the transformation of the optical signal to the electrical signal,and non-distortion amplification to improve the signal to noise ratio.The signal has better anti-interference ability in transmission,and the signal amplitude is matched with the back digital system.The paper designs the front electronics system of plastic scintillator detector.Based on the SiPM,a photoelectric conversion unit was designed and the working point of the photoelectric conversion unit was tested.According to the characteristics of the output signal of the photoelectric conversion unit,select the current feedback amplification and design the cross-resistance amplification.The bandwidth is about 100 MHz,enough to satisfy the need of the signal frequency with low power consumption about 18 mW.According to the power demand of the photoelectric conversion unit and the preamplifier unit,the power supply conversion scheme of LDO and dc-dc is selected and the power supply management unit is designed and constructed.The stable output ripple noise of the power management unit is about 6mV,and the positive and negative power has about 4mV ripple noise,and the static power consumption is about 328 mW.The front electronics system is composed of photoelectric conversion unit,preamplifier unit and power supply management unit.In this paper,the fraction charge reading detection technology is also studied.Fraction charge reading detection technology improves the photoelectric conversion unit,and the fast signal from SiPM is readout for detection.The photoelectric conversion unit and the scintillator form the detector probe.Compared with the standard signal,the timing precision of the fast signal is higher,and the constant fraction timing accuracy is increased from 2.91 ns of the standard signal to 1.45 ns of the fast signal.The peak timing was increased from 8.96 ns to 2.66 ns.At the same time,the fast signal retains the capacity of n/? discrimination.Based on the signal characteristics of fast signal,four kinds of signal analysis methods are studied,and two analytical methods can be used to identify PSD.The energy calibration and discrimination ability calculation are carried out for fraction charge reading detection technology.With the energy threshold of 1MeVee,the FOM was 0.61.