Study on temperature rising of stripping foil and stripped electron of China Spallation Neutron Source
Negative hydrogen stripping injection is the only feasible scheme for accumulating beam in high current proton synchrotrons.Currently,the China Spallation Neutron Source(CSNS)employs negative hydrogen stripping injection by using a stripping foil.The intense temperature rising of the foil caused by energy deposition from the negative hydrogen beam passing through the foil is a critical issue which affecting the foil's lifetime and the stable operation of the accelerator.Additionally,the residual high power electron beam generated during the stripping process may have severe consequences,including electron ionization within the foil causing further temperature increase,thermal damage to the vacuum box from electron impacts,e-p instability from electrons captured by the proton beam in the vacuum tube,and significant electron cloud effects from secondary electrons.This paper focuses on two main topics:first,comprehensive simulations of the foil's temperature rise have been conducted using finite element analysis software,taking into account various parameters,including the average number of particle crossings.Simulation results under various software conditions are compared to obtain the temperature field distribution on the stripping foil and predict surface temperature increases for future higher beam power.Secondly,the electron distribution following the stripping process is analyzed based on theoretical calculations and Geant4 simulations.The 3D computational model is refined by considering the electromagnetic field and beam conditions in the CSNS injection area,and a scheme for capturing stripping electrons is proposed by determining the optimal position for the electron collection device.
China Spallation Neutron Sourcenegative hydrogen stripping injectionstripping foiltemperature risingelectron collection
万方数据
维普
