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W. Kozanecki & M. Weaver. Luminosity-monitor locator scans. Beam conditions (same as 18 Sep 03) LER: by-4, 300 mA, buckets 400-3400. BPM measdef @ bucket 3200 HER: by-4, 300 mA, buckets 0-3000. BPM measdef @ bucket 200 monitor angles both with ST BPMs & LIPP/HIPP monitoring fbks
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W. Kozanecki & M. Weaver Luminosity-monitor locator scans • Beam conditions (same as 18 Sep 03) • LER: by-4, 300 mA, buckets 400-3400. BPM measdef @ bucket 3200 • HER: by-4, 300 mA, buckets 0-3000. BPM measdef @ bucket 200 • monitor angles both with ST BPMs & LIPP/HIPP monitoring fbks • monitor temps & vacuum throughout the scan • Procedure (same as 18 Sep 03, exc. for *) • optimize lumi on tunes; trickle* throughout • scan HER-LER YP manually (Multiknob fbk *) • IPXY stays on faster stabilisation • still need some settle time @ each step • set YP to optimum; scan LER XP manually (Multiknob fbk *) • reset YP to optimum @ each step* • optimize tunes @ each step • increase currents* ahap to check for systematic biases in LIPP/HIPP @ high I (thermal effects)
9 May 05 LSP vs. YP+ (ST) opt = -1.12 mrad 3.34 mrad 3.70 mrad LSP vs. YP- (ST) opt = +2.23 mrad 18 Sep 03 9 May 05 LSP vs. YP- (ST) opt = +1.09 mrad 4.0 mrad 3.68 mrad Luminosity monitor locator scans (YP): 18 Sep 03 vs 9 May 05 LSP vs. YP+ (ST) opt = -1.76 mrad 18 Sep 03
Luminosity monitor locator scans (YP): 18 Sep 03 vs. 9 May 05 YP+ (LIPP) vs. YP+ (ST) YP+(LIPP) opt = -5.3 mrad YP+ (LIPP) vs. YP+ (ST) YP+(LIPP) opt = +6350 mrad 18 Sep 03 9 May 05 YP- (HIPP) vs. YP- (ST) YP-(HIPP) opt = -0.48 mrad YP- (HIPP) vs. YP- (ST) YP-(HIPP) opt = -565 mrad 18 Sep 03 9 May 05
Luminosity monitor locator scans (XP): 18 Sep 03 vs. 9 May 05 18 Sep 03 9 May 05 LSP vs. XP+ (ST) opt ~ 9.6 mrad LSP vs. XP+ (ST) opt ~ 9.25 mrad 18 Sep 03 9 May 05 LSP vs. XP+ (LIPP) opt ~ 1250 mrad
High current scan (I) 400:3400:2 HER ST BPMs no longer meaningful YP+ (ST) vs time LIPP BPMs saturate 0:3400:2 YP+ (ST) vs LER current 0:3000:2 throughout HER ST BPMs saturate
High current scan (II) YP+ (ST) vs LER current YP (LIPP) vs YP+ (ST) YP (LIPP) vs YP+ (HIPP) YP (HIPP) vs YP+ (ST)
High current scan (III) LER current vs time YP+ (LIPP) - YP+ (ST): 0.053 mrad/mA YP- (HIPP) + YP+ (LIPP) YP- (HIPP) + YP+ (ST): 0.067 mrad/mA
Summary • The optimum LER YP, as measured by any 4 • LER or HER ST BPMs • LIPP or HIPP BPMs has shifted by a few hundred mrad compared to Sep 03. The present optimum settings are • LER ST = - 1.12 mrad LIPP = 6350 (+117)mrad • HER ST = + 1.09 mrad HIPP = - 565 (+ 145)mrad corrected to a LER beam current of 2.5 A • The optimum LER XP has not changed much: • LER ST = 925 mrad LIPP = 1250 mrad • The LER & HER ST BPM are now consistent • in y-scale • in optimum YP
Appendix: documentation & data sets • PEP-II e-log: 9 May 05 day shift • All data in PHYSICS4_DATA:[pep2.ip.witold.spr05] • LER YP scan • LERYP_LERBPM_M1_9MAY • LERYP_HERBPM_2_9MAY • LER XP scan • LERXP_LERBPM_M1_9MAY • High-current scan • LERI_LERBPM_M3_9MAY • Temperature & IR2 vacuum througout the experiment • LERYPXPI_TEMPS_1_9MAY.DAT & .MAT