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Generalities. Once more excellent preparation and dry runs both allow a quick start and a very efficient beam test period Very good beam availability from the injectors All systems and applications fully operational Most of the tests done with LHCPROBE, intensity of 6e9 protons
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Generalities • Once more excellent preparation and dry runs both allow a quick start and a very efficient beam test period • Very good beam availability from the injectors • All systems and applications fully operational • Most of the tests done with LHCPROBE, intensity of 6e9 protons • 12 bunch extraction done as well, all BI checked and O.K. • Particles sent within estimated budget : • Protons: <1014 per line • Ions: <1011 per line
TI 2 and TI 8 trajectory studies • TI 2: • RBIH.610104 (MDLH): consistent changes with requested trims • RBIB.610405 (5 MBE): w28: found ~+30 mrad / MBE vs. model and had to add a bump to restore needed aperture. w39: Switched MBE to MBB CC (JW) and removed the additional bump -> small trajectory excursion. • MBIAV.20637 (17 B340): w28~-10 mrad/magnets vs model. Not observed this time, tbc with model analysis. • TI 2 and TI 8: • Bare trajectory: traj. excursion within aperture (with no corrector powered); beams reach downstream TED • Each TL trajectory corrected with few correctors with strength below 20 mrad • Nothing pathological found in the steering optimisation.
Switch MBE.610405 to MBB calibration curve -still with artificial aperture bump in (otherwise bare trajectory)
New MBE calibration with artificial aperture bump removed. See improved (bare) trajectory
TI 2 and TI 8 trajectory studies TI 2: RBIH.610104 (MDLH): consistent changes with requested trims RBIB.610405 (5 MBE): w28: found ~+30 mrad / MBE vs. model and had to add a bump to restore needed aperture. w39: Switched MBE to MBB CC (JW) and removed the additional bump -> small trajectory excursion. MBIAV.20637 (17 B340): w28~-10 mrad/magnets vs model. Not observed this time, tbc with model analysis. TI 2 and TI 8: Bare trajectory: traj. excursion within aperture (with no corrector powered); beams reach downstream TED Each TL trajectory corrected with few correctors with strength below 20 mrad Nothing pathological found in the steering optimisation.
Bare TI 2 trajectory (all corrector kicks removed at the exception of the ones linked to extraction bump)
Bare TI 8 traj (all corrector kicks removed at the exception of the ones linked to extraction bump)
TI 8 trajectory after MICADO optimisation Using few correctors per plane (typically 3, about 20 mm kick)…
TI 2 trajectory after MICADO optimisation Using few correctors per plane (typically 3, about 20 mm kick)…
Comparison with TI 2 proton trajectory:Difference is very small –when SPS proton beam tunes are used.
Comparison with TI 8 proton trajectory:Difference is very small, mostly dp/p in H plane.
TI 2 and TI 8 Optics studies • Dispersion measurements taken with: • Bare trajectory • Corrected trajectory with minimum small kicks • Fine dispersion (high statistics) measurements taken (OP team) over dp/p=-/+ 0.2% using corrected trajectory • Kick response measurements done in TI 8 (KF) • To be analysed in details – compare with updated model • Screen matching measurements done (VK). H and V emittances measured. Tbc.
TI 2 and TI 8 Optics studies - cont’d • w25 and w28 data analysis vs. model (KF et al.) indicate a possible • DK/K = ~1.006 for MQIs • MBI b3 component of ~ -4.5e-4 @ r=25mm • MBI b2 component of ~1.35e-4 @ r=25mm • Continued checks of theoretical model: • Changed Ks of main MQIs in TI 8 by -0.6% (KF) • Took kick response measurements • To be analysed and checked vs. b3 and b2 components
Outcome (preliminary) Measurements are best reproduced with model included: • TI 8: • H : b2+b3 • V : DK/k +b2 + b3 + Initial cdts Dy Dpy • TI 2 : • H : Dk/k + b2 +b3 • V : Dk/k + b2 +b3
BPM calibration(JJG, LJ, RJ et BI team- BG) • TI 2: • Earlier measurements indicated 10% BPM scale factor error • w28: BPM calibration done with BTVs • Scale factor error confirmed • Calibration left in • TI 8: • Trajectory bumps prepared to provide large excursion at BPMI.844 and BTVI.844 (BG) • BPM calibration performed with BTVs • Same scale factor confirmed • Calibration left in
TI 2 and TI 8 aperture studies • Aperture explored in both lines in H and V, using one-line model and dedicated knobs (BG et al.) • To be analysed in details – Preliminary results indicate no bottlenecks and a symmetric aperture. –tbc. • Momentum aperture: prelim. results: +/- 0.035 to 0.4%, as expected.