Unusual fourth order deformation of beam due to space charge

Dong-o Jeon
PACS2001. Proceedings of the 2001 Particle Accelerator Conference (Cat. No.01CH37268)  
Unusual fourth order core deformation in y-phase space is observed in the simulation of SNS ring without lattice imperfections. The fourth order core deformation happens for a wide range of tunes, whereas an asymmetric deformation takes place when bare tune ν y is 5.53 to 5.74. When ν y is close to 6, 2:1 resonance appears in both planes. Extensive numerical simulation indicates that the difference resonance 2ν x -2ν y =0 from space charge potential and dispersion effect are playing a crucial
more » ... playing a crucial role. Similar effect is expected near the resonance 2ν x -2ν y =P with a superperiod P. This is unusual because the SNS ring under model has a perfect four-fold symmetry and operating points are far from structural resonances. Also an interesting observation on equipartitioning is presented in section 4.
doi:10.1109/pac.2001.988052 fatcat:zjkhzedsxvddrfinfhvqtz7jja