Some Observations on Bunch Lengthening
نویسنده
چکیده
The phenomenon of current dependent bunch lengthening discovered at AC0 and ADONE about seven years ago can be used as an engineering diagnostic tool to examine how the longitudinal electromagnetic field of a beam couples to its surroundings. 1 The importance of isolating such coupling factors is that they may give rise to damaging instabilities. Another practical reason for studying the effect is that if bunch lengths grow anomalously beyond those calculated on the basis of classical theory, 2 the effective luminosity of storage rings, particularly those employing low beta insertions, may be reduced. 3 As in most other electron storage rings, the effect at SPEAR is observed to be large and may play a role in proton rings if the beam is highly bunched.
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