MCC meeting, 2 May 03W. Kozanecki Current-dependence of PEP-II beam sizes Current-dependence of PEP-II beam sizes as measured on 30 Apr 03, after moving the LER to the ½ integer LEB onlyLEB only procedure: –at each LEB current, optimize LER tunes on lifetime –record beam sizes, tune tracker, tune knobs In collision: vary eitherIn collision: vary either –I constant I (HER) or I constant I (LER) procedure: –at each current setting, »top-off the beam whose current is kept constant »optimize (all 4) tunes on luminosity –record currents, lifetimes, luminosity, L SP, beam sizes, tune tracker, tune knobs –HER tune: as left. after HER nu scan, i.e. nu_x ~.546 (as per UW’s calibration of HER tune MKB using tune-scan spectra)

MCC meeting, 2 May 03W. Kozanecki The tune? which one do you mean? LER x-tune This expt. Tune tracker disfunctional at this time Tunes actually comparable

MCC meeting, 2 May 03W. Kozanecki LER y-tune Tune readback ~ correct at these times

MCC meeting, 2 May 03W. Kozanecki HER x-tune Actual value ~.546 (UW’s calibration of tune knobs) Actual value est. ~.52 at this time Tune tracker disfunctional

MCC meeting, 2 May 03W. Kozanecki HER y-tune Tune readback ~ correct at these times

MCC meeting, 2 May 03W. Kozanecki LER beam size in single-ring mode LER current LER x-sizeLER y-size  x ~ 1.5 mm: no variation from 200 to 1350 mA Perhaps very small (3%) increase in  y over the same current range transversely unstable

MCC meeting, 2 May 03W. Kozanecki Vacuum pump readings in LER straights: any e - cloud? above 2 pumps are the ‘worst’ No significant electron/pressure activity up to 1350 mA

MCC meeting, 2 May 03W. Kozanecki LER current HER current L SP LER current L SP in collision: vary I(e + I HER = 0.2, 0.6 A

MCC meeting, 2 May 03W. Kozanecki LEB size in collision: vary I(e + I HER = 0.2, 0.6 A LER current LER y-size LER x-size LER y-size

MCC meeting, 2 May 03W. Kozanecki Beam sizes in collision: vary I(e + I HER = 0.2, 0.6 A LER x-size HER x-size L SP 4 % 18 % HER y-size 12 % 30 %

MCC meeting, 2 May 03W. Kozanecki HER current HER lifetime LER lifetime LER inverse lifetime Beam lifetimes in collision: vary I(e + I HER = 0.2, 0.6 A

MCC meeting, 2 May 03W. Kozanecki LER current HER current I-I- I - (mA) LER current L SP in collision: vary I(e - I LER = 0.6, 1.3 A L SP

MCC meeting, 2 May 03W. Kozanecki LEB size in collision: vary I(e - I LER = 0.6, 1.3 A LER x-sizeLER y-size LER current I - (mA)

MCC meeting, 2 May 03W. Kozanecki Beam sizes in collision: vary I(e - I LER = 0.6, 1.3 A HER x-size LER x-size 16 % HER y-size 33 % L SP 12 % 23 %

MCC meeting, 2 May 03W. Kozanecki I - (mA) LER current Beam lifetimes in collision: vary I(e - I LER = 0.6, 1.3 A LER lifetime HER inverse lifetime

MCC meeting, 2 May 03W. Kozanecki Summary LER beam size in single-ring modeLER beam size in single-ring mode –No variation in  x from 200 to 1350 mA (  y : + 3 % ?) –no indication of e - cloud activity suggested by beam-size data In collision, varying the LER current only (0.2  1.3 A)In collision, varying the LER current only (0.2  1.3 A) (LER y size not usable) –LER x-size independent of LER current (LER y size not usable) –HER x-size independent of LER current –For 0.6 < I + < 1.3 A (I - ~ 0.6 A) HER y-size increases by ~ 30 % L SP drops by 18 % –Lifetimes 1/  + linear with I +, independent of I -  - drops ~smoothly with increasing I +

MCC meeting, 2 May 03W. Kozanecki Summary Summary (continued) In collision, varying the HER current only (0.2  0.8 A)In collision, varying the HER current only (0.2  0.8 A) –HER x, y-size independent of HER current –For 0.2 < I - < 0.6 A (I + ~ 0.6 A) LER x-size increases by ~ 16 % L SP drops by 12 % –LER x-size (overall) independent of LER current increases by 27 % (1.65  2.1 mm) for 0.2 < I - < 0.8 A –Lifetimes  - independent of I -, drops with increasing I +  + independent of I -

MCC meeting, 2 May 03W. Kozanecki Appendix: data files HER tune scanHER tune scan (not discussed here) PHYSICS3_DATA:[pep2.coll.apr2903md] –hnuxyscan_T_1_30Apr –hnuyscan_T_1_30Apr LEB onlyLEB only PHYSICS3_DATA:[pep2.ler.apr2903md] –lumb_noHER_T_1_30Apr »eliminate points 1-52, 70-89, , , , –lervass_T_1_30Apr In collisionIn collision PHYSICS3_DATA:[pep2.coll.apr2903md] –lumb_T_2_30Apr »Varying LER current, I(HER) = 0.2, 0.6 A: eliminate points , , »Varying HER current, I(LER) = 0.6, 1.3 A: eliminate points 1-75, , , –lervass_T_2_30Apr

MCC meeting, 2 May 03W. Kozanecki Spare slides

MCC meeting, 2 May 03W. Kozanecki LER tunes in collision: vary I(e + I HER = 0.2, 0.6 A LER x-tuneLER y-tune LER_nux.MKBLER_nuy.MKB

MCC meeting, 2 May 03W. Kozanecki HER tunes in collision: vary I(e + I HER = 0.2, 0.6 A HER x-tuneHER y-tune HER_nux.MKB HER_nuy.MKB

MCC meeting, 2 May 03W. Kozanecki LER tune tracker suspect? LER tunes in collision: vary I(e - I LER = 0.6, 1.3 A LER x-tuneLER y-tune LER_nux.MKBLER_nuy.MKB

MCC meeting, 2 May 03W. Kozanecki HER tunes in collision: vary I(e - I LER = 0.6, 1.3 A HER x-tuneHER y-tune HER_nux.MKBHER_nuy.MKB