Low Energy X-ray Silicon Absorbed Dose Measuring Method

With the research progress of China's manned spacecraft and the research progress of atomic energy development technology,higher requirements are put forward for the stable operation of semiconductor components in complex radiation environments.Accurate measurement of X-ray silicon absorbed dose is the basis for studying the radiation effect of components and developing anti-radiation reinforcement technology for electronic devices.Since it is difficult to directly measure the absorbed dose of silicon materials,this paper obtains low-energy continuous by referring to the method of measuring water absorption dose in medicine.X-rays are commonly used to absorb the dose of radioactive water,and then combined with the Monte-Carlo method to construct the water phantom and silicon model using the Geant4 bionic kit.The simulation calculates the absorbed dose conversion factor of silicon and water.We only need to pass the measured water.The absorbed dose can be converted to the absorbed dose of silicon.The main research contents of this paper are as follows:(1)Firstly,the radiation quality that meets the measurement requirements is established for the X-ray machine used,wherein the first half-value layer and the second half-value layer of the X-ray radiation quality of the 40 kV,50kV,60 kV tube voltage are experimentally measured.The homogeneity coefficient is compared with the JJG912-2010 standard.The maximum deviation is not more than 5%.This is in line with the requirements.The X-ray machine has an inherent filtration of0.118 mmAl,which does not exceed the 3.5mmAl specified in the ISO-4037 standard,and 40 kV respectively.The effective energy corresponding to the 50 kV and 60 kV tube voltages is 19.805 keV,24.059 keV,and 31.391 keV,respectively.(2)By introducing the standard methods of measuring X-ray water absorption doses of DIN 6809-4,IAEA TRS277 and IAEA TRS398,it is found that the correction factors used in the DIN 6809-4 standard are numerous,resulting in uncertain measurement results.High degree,so the method of measuring the low energy X-ray water absorption dose is measured by the method of TRS277 based on the calibration of the ionization chamber or the air kerma calibrating ionization chamber,and the ionization chamber is calibrated based on the water absorption dose calibration factor with less correction factor.The TRS398 procedure measures the calculation of low energy X-ray water absorption dose.(3)The energy spectrum distribution of low-energy X-rays at 40 kV,50kV,and60 kV tube voltages is simulated by SpekCalc program.It is used as the basis for simulating dose of simulated X-rays in water phantom and silicon phantom,and is calculated by Geant4 program.The results of the energy absorption conversion factors of low-energy X-ray silicon and water,that is,40 kV,50kV,60 kV tube voltages are6.2676,6.7020,6.9290 compared with the values ??obtained by the mass-energy absorption coefficient method,and the two are in good agreement.Therefore,a new method for measuring the absorbed dose of low energy X-ray silicon is provided.