Title: Tune shift of coherent beam-beam oscillations
Abstract:The coherent beam-beam oscillation is a good probe to the beam-beam interaction in storage rings. It can artificially be excited by a frequency-changeable kicker. The amplitude of the coherent oscilla...The coherent beam-beam oscillation is a good probe to the beam-beam interaction in storage rings. It can artificially be excited by a frequency-changeable kicker. The amplitude of the coherent oscillation can be very small, as long as it is above the sensitivity level of the detector, so that it does not disturb the beam-beam phenomena. The beam emittance can then be estimated by the observed tune shift of the coherent oscillation. However, in order to make use of this, we need a relation between the tune shift of the coherent {pi}-mode oscillation, {Delta}{nu}{sub {pi}}, and the so-called beam-beam parameter {xi}. When there is one bunch per beam and there is only one collision point in the ring, the {pi}-mode tune shift has been given by {Delta}{nu}{sub {pi}}={lambda}{xi} with {lambda}=2 and 1 by Piwinski and by Hirata, respectively. (In this paper we discuss only the linear term in {xi}.) An intensive analysis has been done in the TRISTAN Accumulation Ring at KEK using Hirata's formula, which seems to be the better among the two. However, the value of the horizontal emittance estimated in this way has always been smaller by some 30 percent than the value computed from the design optics. The purpose of the present paper is to solve this discrepancy by reconsidering the theory of the coherent beam-beam interaction. (author) 6 refs., 3 figs.Read More
Publication Year: 1990
Publication Date: 1990-04-01
Language: en
Type: article
Access and Citation
Cited By Count: 37
AI Researcher Chatbot
Get quick answers to your questions about the article from our AI researcher chatbot