1. RHIC Polarimetery A.Bazilevsky for RHIC Polarimetry group RHIC Spin Collaboration Metting April 10 (Friday), 2009

2. pC measurements Fills 10300 (Mar6) – 10522 (Apr 9) Pol-1 measure systematically lower than Pol-2 Blue1/Blue2  1 from Fill 10476 Yell1/Yell2  1 from Fill 10505 Online Polarization (%), not normalized (!) vs fill

3. Rate history Runs in reasonable conditions (below 3 MHz) Blue-1: since fill 10476 Blue-2 :  Ok Yellow-1: since fill 10505 Yellow2: since fill 10414

4. pC-Blue vs HJet Hjet/pC is stable over fills within (large) stat. errors (of HJet) HJet: =32% (fills 10402-10508) HJet/Blue1  0.96  0.04 (before target change, fill10476) HJet/Blue1  0.84  0.04 (after target change, fill10476) HJet/Blue2  0.82  0.02

5. pC-Yellow vs HJet Hjet/pC is stable over fills within (large) stat. errors (of HJet) HJet: =36% (fills 10439-10508) HJet/Yell1  1.02  0.03 (before target change, fill10505) HJet/Yell1  HJet/Yell2 (after target change, fill10505) HJet/Yell2  0.84  0.03

6. Another APEX exercise: Polarization, “rate” corrected Fill 10508 Energy correction assumed to be an offset (baseline shift) – should be confirmed If so, it may explain the “rate” effect (target dependence and pol1/pol2 difference) Plans: Put pulses in other bunches (now only in bunch0) Vary pulse amplitude After correctionBefore correction  2 /NDF=12/9  2 /NDF=24/9 Very thick targets (very high rate, >5MHz)

7. Backups

8. pC Monitoring Generator pulses Carbon Ekin ToF

9. pC monitoring Low rate example: 10429.013High rate example: 10346.007 Pulse ToF vs time Event rate vs time Pulse rate vs time Pulse amplitude vs time

10. A N vs energy E beam = 100 GeV Any shift in energy measurements lead to a shift in A N (asymmetry)

11. FastOffline vs Online From Xuan Li FastOffline: Use “deadlayer” concept to correct energy: all energy shifts are attributed to change in Si DeadLayer Offline: Yell1/Yell2  0.9 Online: Yell1/Yell2  0.8 Corrects about half of “rate effect” Flattop

12. FastOffline vs Online From Xuan Li FastOffline: Use “deadlayer” concept to correct energy: all energy shifts are attributed to change in Si DeadLayer Corrects about half of “rate effect” Offline: Yell1/Yell2  0.96 Online: Yell1/Yell2  0.89 Injection

13. FastOffline vs Online From Xuan Li FastOffline: Use “deadlayer” concept to correct energy: all energy shifts are attributed to change in Si DeadLayer Flattop Offline: Blue1/Blue2  0.88 Online: Blue1/Blue2  0.86

14. FastOffline vs Online Injection FastOffline: Use “deadlayer” concept to correct energy: all energy shifts are attributed to change in Si DeadLayer Offline: Blue1/Blue2  0.93 Online: Blue1/Blue2  0.93