IR correctionsApril 1st 2009

Fulvia Pilat

APEX Meeting, April 3, 2009

APEX Schedule March 31 - April 1 2009

3:30am00:30am8pm 10:30pm

08-27Optics, beta*measurementsBai

Store rot9312x12 rampBBQ

OPERATIONSIR nonlinear corrections Pilat

6am

Store rot936x6 ramp

09-05D0-DX studyMacKay

Test of beta*=0.5mramp Bruno Tepikian

8am

No beampp93lowbeta

AGS OFF

Injection

DrivenTripletOscillationsmeasurementMintyThieberger

09-22Spin tune vs. orbitPtitsyn, Bai

Injection

intro Normal sextupole and skew sextupole in the IR6 and IR8 triplets gets

readjusted during the set-up phase. Blue got adjusted several week ago, yellow slipped during set-up and ramp-up, and was canceled in the last 2 APEX sessions due to down-time

12x12 rotator ramp, no Artus, IPM, BBQ on the ramp, anticogged (blue used by driven triplet oscillation study)

Check/fix orbit, coupling, separate tunes >0.012

Take BBQ tune data as a function of bump amplitude (IR bumps for sextupole correction span both triplets)horizontal bump normal sextupolevertical bump skew sextupole1 normal and 1 skew sextupole per triplet available to correctcorrectors at xmax affect mostly the H-tune, at ymax mostly the V-tune, not quite orthogonal knobs but close

Nice operational instructions by Chris Zimmer:http://www.cadops.bnl.gov/AGS/Operations/docum/NLOCorrection.html Instructions are also in OpsWiki under the name 'IRBump‘

Sev/Chris working on automation of correction

Coupling at yellow rot store

Found large (~0.08) coupling at yellow storeTried Decoupling application (did not come up)BBQ coupling monitor did not work wellEnded up doing manual decoupling (y-sq2 family ~0.9 large)

Beam decay

Successive correction steps

IR8normalsextupole

IR8 skew sextupole

IR6:normalsextupole

IR6:skewsextupole

bumpbump

drift

jumps

BTF measurement

Corrector settings

Effect on tune ripple (Michiko)

Conclusions Blue and yellow IR corrections done BBQ data quality improved by averaging Reduced tune ripple at store Can do better if needed (time went to deal with coupling and BBQ issues) ~2h (Dev or APEX) could get us down to 0.0001 May help on luminosity and polarization Still dreaming to get time to work on octupole and

higher orders…..