Survey Of Techniques For Longitudinal Emittance Blow-Up In The Kaon Factory Collector Ring

A common method to increase beam stability is to enlarge the longitudinal momentum spread. This paper discusses the efficacy, problems and merits of several blow-up schemes involving modulation of either the main rf system or AM/PM modulations of a dedicated high harmonic cavity. The relative efficiency of each scheme when applied to the KAON Factory Collector storage ring is demonstrated using a particle simulation code. 1 Manipulation of the RF Fundamental Studies of emittance dilution using high harmonic cavities have been reported by Boussard[1], Katz[2], Koscielniak[3], Balandin[4] and Rees[5]. It is worthwhile asking why not use modulation of the rf fundamental to achieve some emittance growth. There are several schemes one might consider: (1a) deliberate phase mismatch at injection to give a dipole-mode oscillation. The beam phase-loop is turned off. (1b) deliberate rf-bucket height mismatch to give a quadrupole mode oscillation. The bunch-length loop is turned off. (2) dipo..