Calibration of dose response of radiochromic film to protons

The calibration of radiochromic films (HD-810) irradiated by protons with different energies has been carried out on the tandem electrostatic accelerator. The optical densities of the irradiated films were obtained using spectrophotometer and commercial flatbed scanner, and the curves of the net optical densities versus dose were acquired. The results of calibration corroborate that, in a certain range of absorbed dose, the net optical densities vary linearly with absorbed doses of the sensitive layer and are independent on the energy of protons. The wavelength of light used to measure the optical density has great effect on the linear range, and the linear range of green light (532 nm) is obviously larger than that of red light (670 nm).