Abstract：Calculate the wall correction factor Kwall of spherical graphite cavity chambers by MC (Monte Carlo) method, and study the influence of Kwall about photon energy, wall thickness and graphite density. And the result shows that for the same volume chambers Kwall sharply reduces with energy at the low energy side. As the wall thickness increases, Kwall approximates linearly increase. And when the calculation accuracy is greater than 0.2%, the effect of density can be neglected on the simulation of Kwall. The above results indicate that in order to calculate the wall correction factor of the graphite cavity chamber accurartely, photon energy, wall thickness and graphite density must be considered.The above results indicate that the calculation of wall correction factor needs to consider the influence of photon energy,wall thickness and graphite density.And the calculation of correction factor of the graphite chamber ionization chamber must be high accuracy.
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2019, Vol. 40 
