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The
Relativistic Heavy Ion Collider Run-7 |
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Links for Lumi-Plots:
Link
to Accelerator Performance Reports (pdf files)
Link to day-by-day integrated total luminosity graph (jpg file)
Link to weekly integrated luminosity graph (jpg file)
Link to day-by-day integrated total luminosity graph (jpg file)
Link to weekly integrated luminosity graph (jpg file)
| day-to-day run
history |
run plan Jun 22nd - Jun 26th |
| Jun 22nd: Recovery from APEX this week was like textbook, no delays. Last week turned out to be somewhat better again and we had 80 h at store resulting in 300 ub-1. Yellow (and blue) transmission efficiency is consistently above 90% and even closer to 95% than 90%. However, bunch intensity is limited to below 1.2e9. Other than that we've been fighting the usual suspects of pre-fires, PS failures, lead-flows, over-temps etc.. In addition we had antoher problem with the SC system, the kicker tank also had a motion problem. After a short access the problem was patched. The tank can be used but the cooling efficiency is reduced once again. Right now, Friday morning we were off because of a lead flow problem that transitioned into another power failure in 1000P. We just recovered and have another store up. Jun 15th: probably due to the more moderate and colder weather this week looks a little better (so far). We still had occasional PS failures (tq6, mains) and a few instances of cooling water problems (STAR electronics chilled water leak Thursday morning) together with some RF and software problems (RTDL, corrupted motion controls, FEC reboot etc.). PHENIX needed an access to repair their drift chamber (Tuesday). At that time a photon converter was installed that was removed Thursday during another 1 h experimenter access. APEX happened as scheduled on Wednesday 5 AM - 7PM. The turn around time as good, shortly after APEX we had the 1st store up. On Tuesday some tune adjustments on the yellow ramp were done that seemed to have helped and yellow transmission is now at or above 90% with an intensity limit of just below 1.2e9. We keep running 103_fancyGap. Jun 11th: Saturday we had a long downtime (>12h) due to a series of mini power dips. The STAR 6x6 store happened on Friday. 103_standard pattern was tried to no avail (ramp was aborted) and we returned to 103_fancy. Due to a RF failure we lost a store Monday morning and quenched numerous magnets. We had a few more PS faults including the mains. All together we totalled about 230 ub-1 during this week (not the worst but only 60% of our best week). Yellow transmission remains low (around 90% or just under) and yellow is limited to a max. of 1.15e9 for decent transmission. We reverted to an APEX ramp with special sexupole settings to allow higher intensities but that didn't change the situation. Jun 8th: it took approx. 4 hours to 'recover' from the low energy run. We had one store over night, a fan-fault in the yellow mains in the early hours of today and another 103x103 (with pretty low intensity because of injector problems) late morning. This store died prematurely because of another PS fault. After recovery we put up the low intensity 6x6 store for the STAR TPC calibration. This store should end after 3 hours and is currently in the machine. Over the weekend we should try to run a few 103_standard fills (please start tonight if possible!). We provide collisions in Ir6, Ir8 and Ir2 at this point. We keep running with about 1.1e9/bunch (keep pushing!) and 103 bunches while adjusting tunes, chroms and coupling (if applicable or reasonable) from time to time. Yellow Stochastic Cooling is used with only 1 pick-up. Jun 6th: We went thru another cycle of stochastic cooling being broken and back on again. The pick-up stalled inside the pipe again, was pulled out manually and since yesterday, Jun 5th, we operated it with just one side (reduced gain and efficiency). We will try to repair it again during the maintenance day. The weekend and beginning of the week were rough. Among the problems were many RHIC PS faults, RHIC RF, the AGS bunch merge cavities, weather standdown, assorted QLIs, the stochastic cooling pick-up, booster extraction and RHIC abort kicker pre- and mis-fires (causing massive quench events!). We are trying to catch those in the act by increased instrumentation (unsuccesful so far). We had only ~53 hours at store and totalled somehwat under 200 ub-1 delivered integrated luminosity this week :(. Yellow transmission is still not better than about 90% (for unknown reasons). Intensity seems limited to about 1.15e9/bunch. After the maintenance today we will go into the low energy run (24 h) and return to 100 GeV physics on Thursday, Jun 7th, eve. Jun 1st: The first summer-like thunderstorm hit and caused a power dip during the night. RHIC recovery was about 8 hours and 1 5h store was provided that lasted until 1PM when a blue QLI occured. While recovering from this we had a yellow QLI and found the AC units off in 1000P. The current estimate is about another hour for one blue and yellow PS to repair before we can get back to physics (i.e. ~5:30 PM). After some chromaticity adjustments in yellow the transmission efficiency went up to around 90-92% but intensities still have to be kept under 1.15e9. Stochastic Cooling could be repaired and is back ON. May 31st: The 1st store was in at 6 PM (sharp :)) after APEX. Transmission problems in yellow still persist, at this point we maintain just under 90% in yellow and 95% in blue but with an intensity limit of about 1.1e9. We had stores over night and are off since 6 AM this morning because of a cryo controls problem. Recovery is estimated to done around noon. Stochastic Cooling crew is in trying to repair the tank while we are down. before May 31st: see RHIC Au-Au Run-7 History |
no more 9
AM meetings! Run7 is scheduled to end the morning of Jun26th, after the overnight store (if there is one), otherwise 8AM. -- no more scheduled maintenances! -- Jun 22nd - Jun 26th AM: physics |
RHIC Parameters for 100 GeV Au-Au Run:
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energy[GeV] |
working point (Qx,Qy) |
β* (IP 6 8 10 12 2 4) |
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injection |
10 |
B: (28.23,29.216), Y: (28.22,29.23) |
10 10 10 10 10 10 |
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ramp |
10
-- 100 |
same |
beta squeeze |
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store |
100 |
same |
0.8
0.8 5 7 5 5 |
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RHIC Run-7 sub-runs:
Achieved parameters at 100 GeV run:
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Run 4 delivered
Luminosity:
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