***** ***** Jan 21 2011 ***** **AGS (Vincent): Fast startup: 60-65% pol for 1.5*10^11 Pol and intens are steady: less orbit drift than in previous runs Emit higher than in previous runs Beta beam is btter than in previous runs: magnet realighnment helped ***** ***** Jan 28 2011 ***** **AGS (Vincent): Try to understand JQ effect on emit (scraping near transition) Intensity scan with scraping at the J10 dump at AGS extraction Planned; pol profile, JQ timing, pol vs long. scrape If scaping late at AGS more effective than Booster scrape? **RHIC (Haixin) *Status: beam loss removed by moving hamma_tr quad off time 10 sec later trans eff on the ramp ~99% failures to increase N of bunches: orbit on the ramp, abort kicjer prefire, collimator positions 9 MHz under commissioning: ramped 10^11 with 111 bunches - no problem pol>40% at store Everything is operational except IPM and jet *Plans: 9 MHz developement: with successful ramp try rebucketing with 28 MHz Chrom feedback developement Rotator ramp developement Push vert tune close to 2/3 (0.675->0.672) and check pol. trans. eff. ** Lum. Mon (Hal) Rel lum measured with BBC and ZDC, but there are discrapancies Suggestion: to add 4 more spin patterns ***** ***** Feb 4 2011 ***** **AGS: Vert profile flat, horiz prof steep Intensity scan with different scraping (at AGS or booster), but all goe to the same pol (0.65) at intensity 1.5; steeper pol vs intensity dependence if scraping at AGS Where steeper prif come from? How is it affected by jump quads? **RHIC: Pol 40-50% at flattop 9 MHz ready for more bunches and intensity Rebucketing with 28 MHz demonstarted Issues: IR steering is necessary in every store for collisions; orbit feedback causes large orbit excursion and beam dump many P/S failures Two measurements of pol at different vert. tunes lies on the last year curve: pol higher for tunes closer to 2/3, but beam starts being lost Indication on pol. profile at RHIC, both injection and store from fixed target and sweep comparisons of pC Goals: continue 9 MHz, move to 109x109 bunches, stabilize collimator setup, orbit correction setup, collisions at IP2 after collisions established at IP6&8 ***** ***** Feb 11 2011 ***** **AGS (Vincent) Goals: put jump quads into operation and minimize emit Need timing setup; emit increased enough to affect AtR eff - should be understood Tuning no-JQ machine for optimal emit and then turning on the JQ doesn't work; The quads are a significantly contarint on the setup **RHIC (Haixin) Noise problems in blue due to dump kicker - effected beam size **AGS-CNI (Andrei) Pol. vs intensity - quite large dependence (12% slope), consistent results with all targets Pol. depends on booster scraping ***** ***** Feb 18 2011 ***** **AGS: Jump quads are on since fill 15190; higher polarization in both AGS and RHIC; horiz pol. profile improved; pol. vs intensity dependence reduced Plans: check more profiles, with quad time shift; which jumps dominate the effect **RHIC: Blue dump kicker noise problem fixed; 9 MHz didn't go well due to LLRF problems Rotator ramp developement planned Emittance out of AGS improved; better orbit on the ramp Blue horiz. tune is touching 0.7 at store - need to lower it 10 Hz orbit feedback tested at end of the store - weak impact; will be tested in the beginning To do: bump closure issues; poor lifetime at beginning of store; injection drift compensation; need snake current scan to set spin tune to 0.5 ***** ***** Feb 25 2011 ***** **AGS (Vincent): Jump gauds are on in all fills since Feb.23 (fill 15190): pol. increased at RHIC inj; emit and intens are improving * Plans Optimize resonance timing empirically; get to the state where we can "turn off" resonance jumping without turning off the quads (timing has to be good that a global shift of times misses all the resonances) **RHIC (Haixin): 9 MHz commissioning successful and now it is in operation more room to push chromaticity (raised set values by 2 units on the ramp) 10Hz orbit feedback in use - reduces the lum. iscillation and improve life time Vert. tune swing moved 30 sec earlier on the ramp to cover strong resonance below 100 GeV - no much change in pol. PHENIX rotators set Bunches look shorter with 9MHz/197MHz than with 28 MHz (why PHENIX doesn't see it?) * Plans: Injection/AtR eff for yell (yellow inj kicker timimg adjustement) Injection drift compensation - need chrom. measurements Increase bunch intens. Snake current scan to set spin tune to 0.5 (after PHENIX rotator setup) Poor life time in the beginning of the store - change working point for blue ***** ***** Mar 4 2011 ***** **RHIC (Haixin): * Status Debunching problems with 9 MHz in blue - glitches in 9 MHz (phase jump) - fixed Measured chrom. with 9 MHz on the ramp - a minor adjustment in vert. chrom. Working point pushed lower for better life time; pol. trans. eff semmes to improve in blue Yell intensity pushed up to 1.3*10^11 * Plans: Increase bunch intens; snake current scan to set tune 0.5; poor life time in the beginning of the store - change working point for blue **STAR (Justin Stevens) Showed Ws from 3.5 pb-1; pi0/etas in FMS - need 20 pb-1 ***** ***** Mar 25 2011 ***** **AGS (Vincent): Jump quad effect: pol. vs intensity - no change up to 1.7*10^11, then drop Without jump quad - drops at > 1.0*10^11; different pC targets show similar results Horiz emit. (with JQ) grows from about 11 to 16 at 2*10^11 Vert emit. (with JQ) behavior is not smooth (weired) Vert emit without JQ - stable vs intensity Plot of pol. vs intens from Run6 and Run9: the slope is -4% (-8%) in Run6 (Run9); In this year it was 6% (14%) with (without) JQ; but other measurement with JQ gave slope 11% ... still different measurements are not well consistent because of pC? **RHIC (Haixin): * Status Intensity reached 1.4*10^11/bunch and no effect on pol Lowered vert chrom. on the ramp, started vert. tune scan (0.675, 0.673) Optic correction in blue to reduce beta beat -> PHENIX collision rate increased, but STAR decreased Raise vert. tune in blue -> improved life time * Plan Finish tune scan (0.671,0.678,0.680); increase bunch intens. - AGS can deliver 2.2*10^11 To understand pol. loss we need pol. profile for all fills, vert. and horiz., inj and flatttop; alos develope up and down ramp measurements **AnDY (Akio) 2 mrad cross angle removed - so now single beam background gone and coll. rate increased (by x3-5?) - now we're with lum. 20% of IP6/8 due to beta* * Plan: script the bump removal, then increase lum. thresh. bu 0.05 to see when we get effect of 10-20%; reduce beta* (in APEX); commission of ZDC trigger for loc. pol. ***** ***** Apr 8 2011 ***** ** AGS (Vincent) Damper helps to reduce vert. tails and improve AtR transfer eff. * Plans: quantify effect of jump quads on pol. profile; study of optics (minimize effect of jump quads on emit.) **RHIC (Haixin): * Peak lum of 150*10^30 reached; beam intensity 1.8-1.9*10^11/bunch - so far no limit from 9 MHz cavity; Collimator on the ramp in use Snake current scan +/-5A (+/-150mkrad) - no change in pol. trans. eff. - need to do more * Poolation sensitivity tests: Scanned vert. tune on the ramp - it stays at plateau (tune control is good) Improved orbit rms: good orbit feedback, fixed BPM offset sign reversal and vert. realignment Possible source of pol. loss: misalignment between magnets and BPMs, coupling at later part of the ramp, horiz. tune/chromaticity because of coupling * Plans: Ramp with vert tune 0.71-0.72 to see higher pol can be reached with reduced orbit errors (we measured 0 in Run9) Ramp with vert. tune 0.671 to see if we reached a plateau in pol. trans. eff. Emittance grough due to e-cloud effect; check emit grouth at store without collisions (expect no effect) Test new conf. of the llrf for 9 MHz mode to achieve lower long. emit. and shorter bunches at store Near integer working point **RHIC pol. development (Mei) Evaluate the current RHIC orbit: check pol. with vert tune 0.71,0.72 (pol=0 in Run9 due to imperfection resonance) - since Run9 BPM offset sign error was fixed Possible depolarization through coupling - indicated by horiz. pol. profile * Revisit near integer point: no snake resonance beam-beam: lower order resonances and accomodate higher beam-beam tune shift (spead) * Why do we want to do it again: BPM offset fixed, 10Hz feedback system works, 4 feedback work: closed orbit error ~0.1mm, straight line tunes, straight line chromaticity in horiz. **AnDY (Les) Moved to higher intensity limit to get AnDY in collisions (reached 1.45*10^11/bunch)- effect on STAR/PHENIX minimal Plans: further increase intensity limit, reduce beta* during APEX, commission ZDC for loc. pol.