Influence of Synchrobetatron Resonance on Low-Energy Injection Beam with a Compact Storage Ring

Abstract

The effects of synchrobetatron resonance on a low-energy beam were studied using a compact storage ring. The beam profile and lifetime were measured on and off the resonance line. Although the first and second resonances were dangerous, the beam lifetime became long on the third and fourth resonances due to the vertical beam size enlargement. Through DC ion clearing, it was also found that the betatron tune shift and spread, which are caused by trapped ions, were reduced with a decrease in beam energy, contrary to expectations. These results indicate that the operating point for injection is not particularly limited in narrow regions. Moreover, the possibility of high current beam storage at low energy is suggested by making full use of the third and fourth resonances.