Using the quadrupole moment frequency response of bunched beam to measure its transverse emittance

Tan, Cheng-Yang

Fermi National Accelerator Laboratory

关键词: Quadrupole Moments;    43 Particle Accelerators;    Synchrotrons Accelerators;    Quadrupoles;    Accelerators;   

DOI  :  10.2172/919077
RP-ID  :  FERMILAB-TM-2397-AD
RP-ID  :  AC02-07CH11359
RP-ID  :  919077

美国|英语

来源: UNT Digital Library

【 摘 要 】

The quadrupole moment measured with a quadrupole pickup has been used to measure the transverse emittance of the beam. Unfortunately, the poor S/N ratio in the measurement makes it difficult to produce good and consistent emittance results. One way to enhance the S/N is to kick the beam with a quadrupole kicker and then measure its quadrupole frequency response (QFR) with a quadrupole pickup. This paper will show that if the bunched beam is extremely short, the quadrupole tunes are well decoupled and far apart, and the quadrupole tune spread is smaller than the synchrotron tune, then the emittance can be extracted from the QFR.