APEX Report:March 31 – April 1, 2009

Fulvia Pilat

Time Meeting, April 7, 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

Driven triplet oscillations Thieberger, Minty, +team

Summary: Measurement log of driven triplet oscillation measurements in the blue ring for offline analysis given in table above. Triplet quadrupole Q2 in sector 6 was modulated using 2 actuators driven in phase with variable frequency and amplitude. The triplet positions (8 detectors in all), the beam positions at the IP’s, and the betatron tunes were recorded. Complete data sets were acquired for three driving frequencies. -Thieberger, Montag, Fischer, Michnoff, Minty

Horizontal beam position Horizontal tune

Example of data for actuator drive frequency of 10.30 Hz with successively decreasing drive amplitude

IR corrections (yellow) Pilat, Zimmer

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‘

Binello, Zimmer working on automation of correction for 100 GeV PP run

IR8normalsextupole

IR6:normalsextupole

Effect of IR correction on tune ripple ( from Michiko)

Spin tune study Ptitsyn, Bai

APEX: ramp 2

APEX: ramp 1

operation

300 murad angle -> 0.046 spin tune shift at 250 GeVOrbit angle in snakes

Snake angle in present operation

At 9 o’clock the zero orbit angle at snake location leads to few mm excursion at a neighboring location.In both rings.

Indication of Blue spin tune at injection is further away from 1/2 with no change of snake orbital angle

-0.3mrad snake angle at injection in Blue seems to push the spin tune either close or further away from 1/2

+-0.3mrad snake orbital angle change along the ramp:

Yellow shows difference in polarization transmission Difference in Blue is not so clear . Spin tune close to ½

(?).

Conclusions

APEX Schedule April 8, 2009

4pm

109 bunches

2pm7am 9:30am

Pp93109 bunchesRegular intensity

07-19, 07-20Noise from Main PSSchultheissMinty

6pm

09-05D0-DX studyMacKaySatogata

08-17Tuning ofpp93lowbetaramp Bruno

7pm11:00am

08-17Commissioningpp93lowbetaramp SatogataTepikianPtitsynMarusic, etc.(commissioning team)

pp93lowbetaRampsNo beam

pp93lowbetaRamps w/beamBBQFEEDBACK

Back to physics

pp9312x12 rampBBQ

Injection

08-29, 08-10Polarimeter:rate dependenceHuang,ZelenskiPol team

CONTINGENT:OPERATIONSHigh intensitystudyBai