Energy spectra of high-power ion beams measured with a pile of thin films on FLASH II

The preliminary experimental results obtained for the energy spectra of high-power ion beam(HPIB) with a pile of thin films on FLASH II accelerator are reported. Code was developed to calculate the theoretical energy-loss of proton and C ion beams transmitted through the Mylar films with different thickness. The apertures of Faraday Cups are covered with Mylar films of different thickness, and then the signal attenuations can be recorded with oscilloscope. The energy spectra of HPIB and the diode voltage are obtained according to the signal allenuations. The diode voltage measured with a pile of thin films agrees with the voltage measured with a differential ring. And the ion number versus time curve was given. In addition, the ion energy of HPIB is also measured with Thomson spectrometer and time of flight method and the results agree with those measured with a pile of thin films.