1. Beam intensity profile measurements with the RHIC (AGS) C-CNI polarimeters. Polarization profile measurements. Polarimeter target mechanisms upgrades. RSC meeting, January 15, 2008

2. Yellow polarimeter target motion upgrade -2006.

3. In 2007 the BLUE target motion mechanisms were upgraded again. New precision rotary motion feedthroughs were installed. No backlash, high reproducibility, smooth motion.

4. P-Carbon CNI polarimeter target. Target speed 200 steps/sec → 25 mm/sec linear speed. ~ 100 mm RHIC beam 180 mm 10 mm Scattering angle ~0.5 deg ~1.6 mm

6. P-CNI polarimeter as a wire scanner: Very thin target, practically non-destructive. Very high rate. Very good signal/noise ratio. Delayed C-ion detection. Single bunch measurements. Problems so far : Target alignment. Carbon strips are not straight. Target mechanism positioning accuracy was not satisfactory (positioning to the detector plane, large backlash, target vibrations). Broken rotational feed through. P-CNI polarimeter can be an ideal wire-scanner. Deutron beam horizontal profile

7. Deutron beam horizontal profile measurement, Jan.15. 2008

8. Large emittances with the wrong ATR beamline tune.

9. Measurement after the ATR tune was corrected. Feb.6

10. Measurements at Store, Feb. 7

11. Large emittances at store Feb10, 9:50

12. Horiz. Emittances at injection, consistent with numbers measured in AGS and ATR.

13. Blue horiz profile measurement with Target #1, Febr.15

14. Polarization profile measurement with Target #1

15. Blue.horiz. at store, Target #5, Febr.15.08

16. Yellow polarization profile,Target #1, Febr.15

17. Run 06.

18. Emittance mode measurement, Run06

19. Emittance scan measurement, Febr.15

20. IPM measurements, Febr.15 17 pi 15 pi16 pi

21. IPM measurements

22. Horizontal profile measurements in AGS.

23. Emittance measurement in AGS, single pulse at flattop. Sigma 0.96 mm~15 pi Horiz emittance

26. Target mechanism upgrades. A new target holder and jig for accurate target positioning. New rotational feedthroughs with direct step-motor coupling, larger (3/8” diam) rod and extended bearing support at the end. A new feedthrough support with provision for precision alignment of the target motion axis and translational motion stages. A new target mechanism attachment plates. No need for mechanism realignment. 4-targets (horizontal) for vertical beam profile scans and 6-targets (vertical) for horizontal profile scans. The target ladder can be moved under the beam. All six vertical targets can be used in the same fill. We plan to install one 20um target and one 40 um target in addition to regular (5-10 um) targets to study the systematic error to polarization measurements at different target thickness. Thicker (hopefully straighter) targets will be used for the beam profile measurements.

28. May 28, 18:37, injection

29. April 21, 14:53, at store

30. Summary. The rotational feedthroughs do not provide accurate positioning (even after all upgrades) and have to be replaced. The target thickness for the profile measurements (and polarization measurements ) have to be optimized. Targets mounting on the ladder has to be improved and tested. The CNI polarimeter is an amazing device. It worked in spite of all the above mentioned problems. I hope it will also survive all the improvements we have made with the very best intentions.

31. Emittance measurements in RHIC.