Deconvolution of the Bremsstrahlung Spectrum at the Superconducting TESLA Accelerator Module using Inverse Calculation Method

The bremsstrahlung spectrum generated by the accelerated field emission electrons at the Is' of five superconducting TESLA accelerator modules driving the FLASH (Free Electron Laser in Hamburg) was analyzed using a batch of radiochromic (Gaf-EBT) films sandwiched between lead plates of different thicknesses. The photon doses transmitted through the lead plates were evaluated from the optical density of the Gaf-EBT films. An inverse calculation method based on a genetic algorithm (GA) was used to deconvolute the bremsstrahlung spectrum by utilizing the gamma dose data. The peak and average bremsstrahlung energy were calculated to be 0.50 and 0.65 MeV respectively.