1. 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

2. Overview
LINAC3 & LEIR

3. Overall performance

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

5. 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

6. 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

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

8. Time line Pb54+/bunch Goal (4.5E8/bunch)
: S. Hancock lover εlong
A. Findlay: Frevcorr
Pb54+/bunch
Goal (4.5E8/bunch)
: 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

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

10. LEIR Schottky Where and what is Tank 2 and what has changed?
Xmas
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

11. 65° 71° LEIR Schottky system vs. FWHM = 15kHz FWHM = 27kHz 23.11.2012
Xmas
65°
71°
FWHM = 27kHz
FWHM = 15kHz
LEIR Schottky system
vs.

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

13. Electron beam positions ion beam in energy space
Xmas
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

14. Xmas
Solved.
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

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

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

17. Xmas
S. Hancock, : ”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

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

19. Positive vertical chromaticity in LEIR

20. 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
Pb Intensity doubling to 9.0*108 Pb54+/bunch for HL-LHC (If low-energy-loss during acceleration can be cured)
MD note(s)

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

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

25. 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)

26. YASP output

27. 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

28. Dispersion YASP MADX Dx/beta_rel Element delta DX_madx -108.6467794
UEH11
0.05
UEV11
0.06
UEH12
0.19
UEV12
0.20
UEV13
UEH13
0.21
UEH14
0.24
UEV14
E-12
UEV21
0.01
E-12
UEH21
E-12
UEH22
-0.01
E-12
UEV22
UEV23
-0.25
UEH23
-0.26
UEH24
-0.35
UEV24
UEH31
-0.17
UEV31
-0.16
UEH32
-0.02
UEV32
0.03
UEV33
0.23
UEH33
0.25
UEH34
0.37
UEV34
E-12
UEH41
0.26
E-12
UEV41
E-12
UEV42
0.10
E-12
UEH42
0.09
UEV43
UEH43
UEH44
-0.28
UEV44
-0.29