The Dynamics Investigation And Simulation For Laser Cooling Of Relativistic Heavy Ion Beams At The CSRe

Obtaining high quality ion beams by cooling technology is the basis of precision physics experiments in heavy-ion storage rings.Compared with other cooling schemes,the cooling rate for laser cooling of relativistic heavy ion beams is expected to be much higher and the laser-cooled ion beams could reach ultra-low temperatures.Laser cooling is regarded as one of the most promising techniques to reach high phase-space densities,achieve ordering beam and even crystalline beam for relativistic heavy ion beams at storage rings.In the storage ring CSRe in IMP,Lanzhou,we used a pulsed laser to cool the 12C3+ ion beams.The experimental and simulation results were presented as fellows.In the experiment,a pulsed laser with the wavelength of 257 nm was used to cool the 12C3+ ion beams at an energy of 122 Me V/u.The longitudinal dynamics of the electron-cooled and RF-bunched 12C3+ and 12C6+ ion beams were investigated systematically.The applications of the RF-buncher in the electron cooling and dielectronic recombination experiments in the storage rings were summarized in the paper.The individual lifetimes of the 12C3+ and 16O4+ ions and the proportion of 12C3+ ions in the stored ion beam were measured.The storage lifetimes of these two kinds of ions were calculated theoretically,and the calculated results were in good agreement with the measured results.In the experiment,a number of important prerequisites have been successfully tested for future laser cooling experiments.Based on the experiments on the CSRe,I participated in the laser cooling experiment on the ESR,and observed the interaction between the pulsed laser and the ion beams,which laid the foundation for the realization of the pulsed laser cooling.By considering the laser force and the RF-buncher force,a single particle tracking method was used to simulate the laser cooling process for bunched ion beams,the longitudinal dynamics and the Schottky spectrum to help understanding the experimental results.The calculation of the force and acceptance for both pulsed laser and CW laser provides the reference for the future experiment of combining pulsed laser and CW laser to achieve laser cooing.A new laser cooling experiment for 16O5+ ions with a CW laser is currently been prepared at the CSRe by the Laser-cooling Collaboration,and will be carried out in 2017.16O5+ ions will be the highest charged ions which have been successfully lasercooled in heavy-ion storage rings.The future large-scale facility HIAF(High Intensity Heavy-ion Accelerator Facility)is in construction in Huizhou.In the new facility,we prepare to carry out laser cooling experiment and precision laser spectroscopy experiment for relativistic highly charged ion beams,and also the precision measurement of QED effect.