Beam Size Flip-Flop Measurements R. Holtzapple, M. Billing, B. Cerio In CESR-c conditions with 26 bunches in the CESR, single bunch tune, vertical beam size and luminosity were measured parasitically. The BSM was used to measure the vertical beam size of e+ and e-. Tune was measured with the BPM while pinging vertically. Luminosity was measured with the FLM. These quantities were measured in a stable colliding beam state and in an induced “flip-flopped” state where the vertical beam size changed and luminosity was reduced. 9-06-07

Preliminary Flip Flop Measurement (tunes not measured) Stable Colliding Beams Flip-Flopped State FLIP FLOP

Flip Flop BSM Measurement: end of fill Flip-Flopped State Stable Colliding Beams Pretzing-13 from 7 to 64cu Xtuning 4 from 48 to 5cu Flip-Flopped State

Change in Beam Size: end of fill

Change in Tune: end of fill, pretzing

Change in Tune: end of fill, xtuning

Change in Luminosity: end of fill pretzing xtuning

Flip Flop Measurement: top of fill Stable Colliding Beams Flip-Flopped State FLIP FLOP

Change in Tune: top of fill

Change in Luminosity: top of fill