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