SINGLE-BUNCHTUNE AND BEAM SIZEMEASUREMENTS ALONG BUNCH TRAINSINPEP-II*

By scanning gatedcameras andgated tunemonitors across thebunchpattern during normal colliding-bunch operation ofPEP-II, thetunesandbeamsizesof individual bunches weremeasured simultaneously inthe highandlowenergystorage ringsofPEP-II. The measurements weremadewith1561colliding bunches in PEP-II, arranged intrains of66bunches, witheachbunch inthetrain separated by4.2ns.Thetuneandbeamsize measurements were correlated withthe current, luminosity, andspecific luminosity ofthebunch. The results showavertical tuneshift atthestart andendofthe mini-trains, aluminosity droopalong themini-train, and specific luminosity dropinthefirst andlast bunches of thetrain, sincetheyexperience a different parasitic crossing oneither side oftheinteraction point (IP).