Lead performance throughout the injector chain with focus on LEIR M. Bodendorfer, D. Manglunki MSWG June 4th, 2013 With the help of (in alphabetical order): M.E. Angoletta, G. Arduini, C. Carli, A. Findlay, S. Hancock, S. Jackson, D. Küchler, S. Pasinelli, R. Scrivens, G. Tranquille and the PS & SPS operators

Overview LINAC3 & LEIR

Overall performance

LEIR – Low Energy Ion Ring From LINAC3 & to PS Extr. Septum Injection RF Extr. Kicker Beam Ecooler

LEIR Overview Machine Output Energy Charge state ECR ion source 2.5 keV/n …,29+,… LINAC3 4.2 MeV/n 29+/54+ LEIR 72 MeV/n 54+ PS 5.9 GeV/n 54+/82+ SPS 176.5 GeV/n 82+ LEIR Design Parameter Value Length 78m brel.(Inj. & Ej.) 0.095 0.392 grel. (Inj. & Ej.) 1.0045 1.087 gtransition 2.84 ε*transv. (inj & Ej.) 0.65 μm 0.7μm εlong. (Inj. & Ej.) 0.015eVs/u 0.1eVs/u Tune (Hor. & Vert.) 1.82 2.72 LEIR

Method: Clone copy of operational user NOMINAL -> MDOPTICS Measurements, corrections, and optimization on MDOPTICS Clone copy: MDOPTICS  NOMINAL Goto 2 Milestones: Extensive RF MD LINAC3 Tank 2 phase shift  Intensity goal achieved. frevcorr routinely applied by SPS operators RF Bucket Voltage decrease  lower εlong

Time line 23.11.2012: Goal achieved Pb54+/bunch Goal (4.5E8/bunch)

Time line Pb54+/bunch Goal (4.5E8/bunch) 22.1.2013: S. Hancock lover εlong 29.11.2012 A. Findlay: Frevcorr Pb54+/bunch Goal (4.5E8/bunch) 23.11.2012: R. Scrivens discovers T2-phase effect Extensive RF MD by M.E. Angoletta CVORB change SPS Ops use Frevcorr Xmas Tech stop LEIR stand-by

While LINAC3 intensity remains the “same” Xmas 23.11.2012 While LINAC3 intensity remains the “same” Tank2 phase 65°71°

LEIR Schottky Where and what is Tank 2 and what has changed? Xmas 23.11.2012 Use the LEIR Schottky system as a spectrometer to determine the change in momentum distribution from LINAC3. Where and what is Tank 2 and what has changed? LEIR Schottky Ion Source Tank2 LINAC3

65° 71° LEIR Schottky system vs. FWHM = 15kHz FWHM = 27kHz 23.11.2012 Xmas 23.11.2012 65° 71° FWHM = 27kHz FWHM = 15kHz LEIR Schottky system vs.

More injected beam -> 100% beam loss at RF capture Xmas 29.11.2013 More injected beam -> 100% beam loss at RF capture

Electron beam positions ion beam in energy space Xmas 29.11.2013 Electron beam positions ion beam in energy space Cold electrons Hot electrons 0V Uc Less hot Ions Hot Ions Electron cooling Ekin=e-(Uc+Ue+Ui) vele Δveli Cooling RF adjust Frevcorr necessary

Xmas Solved. 29.11.2013 Different LEIR ion beam intensities results in different acceleration loss (20% to 100%). Correcting Frevcorr brings back the beam. Trev. Tomoscope @ RF capture before Tomoscope @ RF capture after

Frevcorr routinely applied by SPS operators Pb54+/bunch Goal (4.5E8/bunch) SPS ops use Frevcorr Xmas Tech stop

Time line Pb54+/bunch Goal (4.5E8/bunch) 22.1.2013: S. Hancock helps develop lover εlong Pb54+/bunch Goal (4.5E8/bunch) Xmas Tech stop

Xmas 21.1.2013 S. Hancock, 21.2.2013: ”What matters is not how intense your beam is at extraction but also its size.” εlong = 10.8eVs Pb54+/bunch = 5.1E8 εlong = 8.1eVs Pb54+/bunch = 5.0E8

A LEIR NOMINAL cycle (Qh=1.82; Qv=2.72) Continuous electron cooling RF capture @ 1780ms Up to 50% loss Extraction @ 2880ms (Master timer) Magnetic ramp start @ 1823ms 7 injections. First at 215ms, then spaced 200ms. 200μs long. B-field Intensity in 1010 charges vs. cycle time: 0 to 3.6s

Positive vertical chromaticity in LEIR

Outlook LINAC3 & LEIR instrumentation and controls wish list presented at LIU Ion meeting, May 29th, 2013: Power supply checking (By SPS ctrl. Software) Automated Q’ measurement (By PS Software) LINAC3 and LEIR Pepper pots Schottky measurement from CCC Consolidate Ionization Beam Profile Monitors Restart after LS1 with Ar: First beam mid-June 2014 Fixed target Ar run in January 2015 Xe in 2016-2017 Pb Intensity doubling to 9.0*108 Pb54+/bunch for HL-LHC (If low-energy-loss during acceleration can be cured) MD note(s)

Thank you for your attention (spoiler: spare slides ahead)

Restricted maxima search LEIR horizontal tune NOMINAL (6 injections) Cycle time [ms] Fractional tune

Difference of Horizontal tune to reference tune (@ 0mm beam offset) ΔQ for programmed radial offset from -20mm to +20mm -20mm -15mm -10mm -5mm 5mm 10mm 15mm 20mm 1 time step: 20ms Cycle time [ms] Difference of Horizontal tune to reference tune (@ 0mm beam offset)

YASP output

Linear extrapolation of Δp/p Measurement from +10mm programmed radial offset Linear extrapolation: -20mm to +20mm radial offset Cycle time [ms] Measurement from -10mm programmed radial offset Δp/p

Dispersion YASP MADX Dx/beta_rel Element delta DX_madx -108.6467794 UEH11 0.05 -108.594631 UEV11 0.06 -108.5916379 UEH12 0.19 -108.4540057 UEV12 0.20 -108.4510126 -29.7103708 UEV13 -29.51327851 -27.03419573 UEH13 0.21 -26.82629815 -3.659102848 UEH14 0.24 -3.414974121 -2.648617378 UEV14 -2.409566799 2.74087E-12 UEV21 0.01 0.008607013 2.74027E-12 UEH21 0.007818831 2.72836E-12 UEH22 -0.01 -0.00782268 2.72776E-12 UEV22 -0.008611838 UEV23 -0.25 -2.901496482 UEH23 -0.26 -3.92239623 UEH24 -0.35 -27.38481892 UEV24 -30.06436595 UEH31 -0.17 -108.8144791 UEV31 -0.16 -108.8103844 UEH32 -0.02 -108.6660674 UEV32 0.03 -108.6164755 UEV33 0.23 -29.48507857 UEH33 0.25 -26.78910043 UEH34 0.37 -3.286295971 UEV34 -2.27545835 2.69117E-12 UEH41 0.26 0.263626809 2.69184E-12 UEV41 0.260649994 2.72887E-12 UEV42 0.10 0.095436791 2.72953E-12 UEH42 0.09 0.092459977 UEV43 -2.804066827 UEH43 -3.825424558 UEH44 -0.28 -27.31623092 UEV44 -0.29 -29.99979657