Using carbon film for generating secondary particle beams at proton synchrotrons

To determine applicability of carbon films for the generation of ultrarelative positron beams using high energy accelerators a possibility of micron films work at pulse heating characteristic for proton synchrotrons and mechanical loadings appearing when the film is introduced into the beam is investigated. The processes of carbon film obtaining are considered and the results of experiments, conducted on the films which have been introduced into the chamber of 70 GeV IHEP proton synchrotron are discussed. The experiments conducted have shown that carbon films approximately 1 μm thick are efficient targets for positron beam generation using high energy accelerator. The films stand pulse heating up to 2000 K. Application of film targets with the efficiency of 10-20 % produces inconsiderable disturbance in a beam and gives a possibility to ensure simultaneous work of slow output and channels of secondary particles working with the film targets. In the process of the film target operation amplitude of secondary particles current modulation working together with the film target decreases considerably