# Presentation: 689543

## RHIC pp RUN5 Performance

- http://www.agsrhichome.bnl.gov/AP/Spin2005/

## Outline

- The Goal of pp RUN5
- The performance of RUN5
- What has been achieved
- 100 GeV program
- 205 GeV development
- What have we learned
- Summary

## Goal of RHIC pp Run 05

- Provide collisions at 100 GeV for experiments STAR, PHENIX and Brahms
- _[Provided a total of 11.8 pb](slide15.xml)__[-1](slide15.xml)__[ (June 21) luminosity with longitudinal polarization at STAR and PHENIX](slide15.xml)_
- Provided a total of 163 nb-1 luminosity with transverse polarization at STAR and PHENIX
- _[Successfully accelerated/collided 110x110 bunches with a bunch intensity of 1x10](slide23.xml)__[11](slide23.xml)_
- Explore the polarized proton acceleration beyond 100 GeV
- Beams were accelerated and collided at 205GeV
- _[30% polarization was measured in both rings at 205GeV](slide16.xml)_
- _[Two polarization ramp measurements](slide17.xml)_
- An increase of 1mm  vertical rms in yellow decreased the polarization transmission efficiency by close to a factor of 2
- Push the Qy away from 0.7 in Blue didn’t affect the pol transmission efficiency

## RHIC pp performance

|  | Bunch intensity
X1011 | # of 
Bunches | Lpeak
X1030
cm-2s-1 | Lstore
X1030
cm-2s-1 | Lweek
pb-1 | Machine uptime | Pol at Store
Blue/Yellow |
| --- | --- | --- | --- | --- | --- | --- | --- |
| FY04 | 0.7 | 56 | 5.4 | 4.0 | -- | -- | 40% |
| FY05 min | 0.7 | 56 | 5.4 | 4.0 | 0.9 | 40% | 40% |
| FY05 max | 1.0 | 79 | 16 | 8.2 | 3.0 | 50% | 45% |
| FY05 operation | 1.0 | 84 | 9.0 | 4.9 | 1.2 | 52% | 48.5/43.5 |
| FY05 max | 1.12
(61 bunches) | 110
(0.95x1011 protons/bunch) | 13 | 8.2 | 1.8 | -- | 61.9/58.4 |

- Projection

## RHIC integrated FOM

## Average luminosity per store

## Average luminosity per week

- 205 GeV development

- PAC week

- APEX, maintanence

- Transverse spin

## Luminosity lifetime

## Achieved polarization in Blue

## Achieved polarization in Yellow

## Polarization efficiency

- Switch to 100GeV AN

- Fixed the maximum energy cut

## What have we learned

- _[flat orbit vs. zero orbit ](slide19.xml)_
- No difference in polarization transmission efficiency
- _[But, flat orbit introduces stronger coupling and an enhancement on a imperfection resonance at G](slide20.xml)__[](slide20.xml)__[=85](slide20.xml)_
- _[Daily variation of orbit](slide21.xml)_
- _[Beam lifetime at store](slide24.xml)_
- Tighter momentum aperture in yellow than in blue
- Dispersion function sensitive to the local angle bumps at IP6 and 8
- Achieved beam-beam tune shift is smaller than expected
- STAR background issue
- Background with 15% larger beta* yields similar background issue
- Needs shielding
- _[Effect of Brahms magnet](slide22.xml)_
- Yellow injection kicker slow rising time
- Cause emittance blowup of the bunches which are 3-buckets apart

## Summary

- Machine performed well. The total delivered luminosity is well within the C-AD projection. The achieved polarization is above the projection thanks to the great performance of the polarized proton source and the injectors.
- Successfully operated with 110 bunches with 1.0x1011 protons per bunch. Tests of accelerating 110 bunches with 1.5x1011 protons per bunch will take place on Friday APEX session.
- Add more NEG coated pipes
- Improve the vacuum condition at CNI polarimeter
- Design strategies  to fight against the orbit daily variation
- 205 GeV development demonstrated the depolarization resonance is sensitive to the orbit distortion. Machine re-alignment will be arranged during the shutdown

## Acknowledgement

- L. Ahrens, I.G. Alekseev, J. Alessi, J. Beebe-Wang, M. Blaskiewicz, A. Bravar, J.M. Brennan, D. Bruno. G. Bunce, J. Butler, P. Cameron, R. Connolly, J. Delong, T. D’Ottavio, A. Drees, W. Fischer, G. Ganetis, C. Gardner, J. Glenn, T. Hayes, H-C. Hseuh. H. Huang, P. Ingrassia, U. Iriso-Ariz, O. Jinnouchi, J. Laster, R. Lee, A. Luccio, Y. Luo, W.W. MacKay, Y. Makdisi, G. Marr, A. Marusic, G. McIntyre, R. Michnoff, C. Montag, J. Morris, A. Nicoletti, P. Oddo, B. Oerter, J. Piacentino, F. Pilat, V. Ptitsyn, T. Roser, T. Satogata, K. Smith, D.N. Svirida, S. Tepikian, R. Tomas, D. Trbojevic, N. Tsoupas, J. Tuozzolo, K. Vetter, M. Milinski. A. Zaltsman, A. Zelinski, K. Zeno, S.Y. Zhang

## RHIC integrated luminosity: soft-physics-on ~ ev-lumi-off

## 205 GeV development

## With yellow yrms increased by 1mm around the 1st strongat 135GeV

- With yellow yrms increased by 1mm around the 1st strongat 135GeV
- Blue Qy moved away from 0.7

## Polarization profile

## flat orbit and zero orbit

- golden orbit using the latest survey

- Flat orbit:
-     Sum of kicks on the spin vector
-     from quads as well as the dipole
-     correctors = 0

- Orbit through the center of bpms

## Imperfection resonance w. flat orbit

## Orbit daily variation

## Effect of Brahms magnets

-  most effective one: D1
-  also sensitive to the polarity
-  no effect if the magnets are
-    ramped individually with a
-    proper slow factor

## 111x111 bunches

## Beam lifetime at store