A   B   C   D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T   U   V   W   X   Y   Z  

Ieiri, T.

Paper Title Page
TUPTPF032 A Gated Beam-Position Monitor and Its Application to Beam Dynamics Measurements at KEKB 181
 
  • T. Ieiri, H. Fukuma, Y. Funakoshi, K. Ohmi, M. Tobiyama
    KEK, Ibaraki
 
 

Recent high-intensity machines with a multi-bunched beam demand bunch-by-bunch beam diagnostics. Especially in a colliding machine such as KEKB, the beam-beam effect is one of the main issues from the viewpoint of beam dynamics. Recently, KEKB achieved an effective head-on collision by using of crab cavities and gained a higher specific luminosity. A gated beam-position monitor, being capable of measuring the beam phase as well as the transverse position of a specific bunch in a bunch train, has been developed and is used to measure a beam-beam kick at KEKB. The monitor detects the beam position with a resolution of a few micrometers. The monitor demonstrated the effect of the crab cavities and estimated the effective horizontal beam size at the interaction point from a linear part of a beam-beam kick. Moreover, the monitor detected a displacement of the horizontal beam position along a bunch train under the crabbing collision. We estimate that the horizontal displacement is caused by an asymmetric kick of the crab cavities, which is based on a bunch-by-bunch phase modulation due to transient beam loading.