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LHC progress with beam & plans. Of note since last time. Transverse damper Beta beating in the ramp Collimation set-up at 450 GeV & validation LBDS – systematic checks for higher intensity BPMs – variation with intensity RF, full buckets and phase control - PowerPoint PPT Presentation
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LHC progress with beam & plans
LHC planning
Of note since last time
Transverse damper Beta beating in the ramp Collimation set-up at 450 GeV & validation LBDS – systematic checks for higher intensity BPMs – variation with intensity RF, full buckets and phase control And some physics – 2 x 1028 cm-2s-1
11-05-10
LHC planning11-05-10
LHC planning
LBDS – machine protection checks
11-05-10
LHC planning
beta beating in ramp
11-05-10
LHC planning
beating in ramp
11-05-10
Largest -beating at 1.1 TeV
• IR7 seems to be the dominant source
• P. Hagen just finished the MQW measurement campaign
• At 450 GeV P. Hagen’s data agree with the beating corrections
• Remove correction – go with updated calibration curves – test today
BPM versus intensity
Orbit shift when going from low to high bunch intensity gain: 9 109 9 1010 systematic shift of ca. 300 mm; shift seems to be
mainly systematic into one direction; gain switch @ 2 1010
7
LHC planning
Collimation
Summary of Collimation studies (1011 / bunch): collimation settings at 450 GeV for nominal bunch intensity
established (improved beam-based calibration method higher accuracy with increased intensity and correction for halo cuts during setup).
We provoked stored beam losses in H, V and off-momentum (positive and negative) for beam 1 and beam 2. Separate loss maps recorded.
Results looked fully OK in preliminary visual inspection, but further detailed analysis required. Much lower (invisible) losses in tertiary collimators. Like expected in simulations.
All collimators set back to previous settings in the end (low bunch intensity).
11-05-10
LHC planning
Collimators in ramp
11-05-10
Stefano Redaelii
LHC planning
ADT commissioning with beam
11-05-10
LHC planning
ADT
11-05-10
LHC planning
ADT – to do list
11-05-10
LHC planning
Immediate goals 1/3 : 8e10 per beam (S2)
Intensity step 2 to do: BPM intensity calibration Collimation & OFB in ramp LBDS checks – mostly done
check on the RF <-> LBDS synchronisation for B1/B2 Make the 'power off' test of the LBDS with beam circulating
Machine protection BIS test – MZ
the SIS interlock on the beam position at the TCDQ
11-05-10
Most preparation done
LHC planning
Immediate goals 2/3: OPs
Nail down the operational sequence & issues: Injection, ramp, squeeze, Feedbacks etc., references Sequences Trims, settings Alarms Orbit correction, reference orbit, variations with intensity SPS cycle changes
11-05-10
Half day review next Tuesday
LHC planning
Immediate goal 3/3: 2 x 1e11 (S3)
Dodge the intermediate intensity issue Commissioning 1e11 through operational cycle
single bunch per beam up the ramp collimators OFB RF
flat-top collimation, separation on check beating
squeeze to 5 m separation beating
collisions
11-05-10
LHC planning
450 GeV – prep for higher intensity
11-05-10
shifts priority
COL Collimator set-up & loss maps 2 min S2 OK
COL Measure n1 1 1
ABP & co Finish aperture measurements off-mom 1 1
RF Transverse damper 2+ 2 wip
RF & co Abort gap cleaning 2 2 wip
LBDS & BIS No beam – BP checksTCDQ tracking
1 S2
LBDS P6 aperture 1 S2 OK
ABT Injection studies (checks for B2 emittance, TDI thresholds for over-injection, TCDI protection validation checks, essential injection region aperture checks, MKI waveform)
1 2
MPS Setup beam flag - 1 OK
LBDS/MPS Full set of checks at 450 GeV including mains off 2 S2 OK
MPS RF frequency interlock - S2 OK
COL/LDBS Calibration of BLMs at TCTs 1 1
LHC planning
Ramp
11-05-10
shifts priority
Snapback update, Q’ measurement & correction
Parasitic 2 Not critical for lower intensities
Beta beating measurements ditto 1 S2 – checks today OK
Collimators and protection devices in ramp
2 1 S2 - today
Synchronization tests of TCDQ positions and interlocks with other collimators during ramp and squeeze
S2 - today
Beam dumps to qualify MSD update
2 1 OK
Orbit feedback & feed-forward
1 2 S2
LHC planning
Squeeze
11-05-10
Priority
Separation on for S3 1
Golden orbit squeezed, separated 1
Golden orbit squeezed, colliding 1
Drive tertiary collimators with functions (or pre-load)
not need for 5 m
OK
OP sequence – into sequencer… in one go 1 OK
Orbit feedback
Tune feedback if required OK
LHC planning
3.5 TeV prerequisites for higher intensity
11-05-10
shifts priority
COL collimation setup at 3.5 TeV 3 1
BLM BLM thresholds for losses in SC area 2 1
LBDS LBDS MPS checks (3.5 TeV) Calibration of beam loss at TCDQ, response of direct BLM
1 1
LBDS Setup of TCDQ/TCSG to measured beam sizes at 3.5 TeV (through squeeze - interpolated betas)
done 1
LBDS Test of asynchronous dump protection at 3.5 TeV (through squeeze, needs several fills if optics varies)
4 1
SIS SIS TCDQ position interlock checks 0.5 1
LHC planning
Schedule
11-05-10
S2
LHC planning
Conclusions
Stable beams at around the safe beam limit now routine Good progress in ticking off required commissioning
steps for higher intensity MPS, LBDS, Collimation
Should be ready this weekend for first step up 8 – 12 e10 total, 4-6 bunches of 2 e10
1 e11 good at 450 GeV, will now start pushing into ramp and finish required commissioning at 3.5 TeV with higher single beam intensity Pull back to beta* = 5 m.
11-05-10