The Simulation Of Beam Loss In CSRm And The Dynamic Vacuum Study

High intensity heavy ion beams are taken as a research in this paper, the background to high intensity heavy ion beams and its significance are also described in this paper. Moreover, the principle of heavy ion beams collimator is studied in this paper. The tracking of one electron-loss 238U33+ with the reference charge state of 238U33+at the energy of 1.237Mev/u, due to the interaction between the ions and the residual gas will be focused in CSRm ring. With the loss profile, the calculation of the collimation efficiency of CSRm ring and the dynamic vacuum caused by the associated produced desorption gases are presented in this paper. A prototype collimator has been designed and Heavy ion induced desorption measurement will be tested in the CSRm. It makes sense of the project of the collimation of CSRm in future.Firstly, the background to high intensity heavy ion beams and its significance are investigated. In addition, the principle of heavy ion beams collimator is studied. Due to the charge change-generated beam losses and the associated produced desorption gases, a simulative study of 238U32+beam loss due to charge changing processes to compute and track the loss profile is achieved in the CSRm in this paper. Most charge changing particles likely are lost in the second dipole of the four super-period structures in the simulation. Therefore, the collimation efficiency of CSRm ring with the collimator installed at those positions are calculated.Secondly, the factors which affect the collimation efficiency is displayed in this paper. By ignoring the lattice factor, the collimation efficiency of CSRm ring is optimized with different locations of the same collimators and different collimators of the same locations.Finally, the mechanical design of the prototype collimator is given by compare the existing international collimators and our actual situations. Based on the intentional experimental studies on the heavy-ion induced molecular desorption, the prototype chamber consisting of two transversally movable copper beam absorbers, one coated with a few 20 nm Gold and an underlying diffusion barrier made of Nickel and one without coated material, will be used to measure the desorption of heavy ion on HIRFL-CSR. And the dynamic vacuum of the prototype chamber is also simulated.