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A.Zelenski, RSC meeting, October 2, 2009.

Polarized source and LINAC upgrades for 2009-10 Runs. A.Zelenski, RSC meeting, October 2, 2009. Run 2009. 1. Polarized source very reliably delivered beam for 2009 run for depolarization studies in AGS and polarized run in RHIC.

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A.Zelenski, RSC meeting, October 2, 2009.

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  1. Polarized source and LINAC upgrades for 2009-10 Runs. A.Zelenski, RSC meeting, October 2, 2009.

  2. Run 2009 • 1. Polarized source very reliably delivered beam for 2009 run for depolarization studies in AGS and polarized run in RHIC. • 2. The OPPIS delivered sufficient current to implement the strong collimation in the Booster. The emittance control in Booster, AGS and RHIC injection and higher bunch intensity contributed to the RHIC luminosity increase. • Required beam intensity was produced with the shorter 300 us pulses which also contributed to the smaller beam emittances out of the Booster. • 3. The LEBT and MEBT were rebuilt to improve the beam matching to Linac. This resulted in small beam emittance out of Linac. • 4. Smaller beam emittance in AGS contributed to the higher beam polarization out of AGS. • 5. Small beam emittances in RHIC contributed to the beam luminosity increase.

  3. Old LEBT & MEBT 35 keV Optics box 750 keV

  4. New LEBT/MEBT, 35-750 keV OPPIS Spin-rotator Einzel lens

  5. A new 750 keV MEBT line

  6. Compromises in Run 09. • Einzel lens beam focusing to RFQ worked fine for the polarized beam but introduced big losses for unpolarized high intensity beam due to space-charge effects. It was replaced back to the solenoid focusing, which introduced unwanted ( ~ 440 deg) spin rotation and reduced molecular component suppression. • Common line for polarized and unpolarized beams limited the beam tuning and collimation for the molecular component suppression. • Vacuum in the LEBT was spoiled to improve space-charge compensation for unpolarized beam, which caused ~15% polarized beam loss due to H- ion stripping.

  7. Run 09 projections and measurements. + • New LEBT/MEBT beam-lines to improve beam matching from RFQ to LINAC, reduce emittances after the LINAC. • Spin precession in LEBT is reduced, hopefully we can gain some polarization. • Laser beam transport lines were modified, hopefully we will still have a good matching, needs more work with polarimeter. • Hopefully, better matching to LINAC will work and we get better transmission through LINAC and smaller emittances. • Molecular component suppression is different (weak), we may loose some polarization or have to find the tune with better suppression. +/- + + -

  8. Linac emittance in Run 09

  9. Further upgrades for 2010 Run New decelerating Einzel lens

  10. Molecular component suppression by the the decelerating Einzel lens.

  11. Polarization oscillations in the Sona-transition, Run - 07. 85% After Sona-transition upgrade, Run 07 Simulations and field measurements. A new diam. 4.0” Sona-shield A new Correction Coil Optimized positions for shield and CC 50 A Polarization at 200 MeV vs. Correction Coil current

  12. Febr.28, 2008 82%

  13. 2009 projections. After polarimeter electronic change Measured ~78-80% After the linac LEBT/MEBT-upgrade, smaller linac emittances should give rise to smaller Booster emittances. Beam intensity ~3·1011 with emittances Eh~10 pi, Ev ~5-8pi will be available for injection to AGS (without any scraping). Shorter 300 us linac pulses can be used to produce 2.0-2.5 ·1011, which should give even smaller emittances and better polarization.

  14. AGS polarization vs beam intensity May 19, 2009

  15. P-Carbon polarimeter calibration in comparison with elastic p-Deuteron scattering. E.Stephenson A(pD) =0.524+/-0.003

  16. 200 MeV p-Carbon and p-D polarimeter. D-recoil arm 12 deg. Proton arms pD-elastic scattering pCarbon elastic scattering at 18 deg angle

  17. Polarimeter calibration, Run 2002, April 7-9.(after EL installation). Current in polarimeter reduced to 40-50 uA on U5.

  18. Plans for 2010 • Rebuilt the LEBT for polarized and unpolarized beams to improve transmission and suppress molecular component for polarized beam. • Upgrade the 200 MeV polarimeter to improve the absolute accuracy of polarization measurements. • Proton-Deuteron elastic scattering A= 0.524+/-0.003 • P-Carbon elastic scattering at 18 deg. A=0.995 • There is a plan to develop combined (solenoid-Einzel lens) focusing lens for RFQ to eliminate unnecessary spin precession in the present focusing solenoid.

  19. OPPIS upgrade with the Fast Atomic Beam Source. He –ionizer cell serves as a proton source in the high magnetic field. 1 2 3 4 5 6 7 8 H- H+ H0 The project is funded for implementation in 2009-12. Atomic H injector in collaboration with BINP, Novosibirsk. New superconducting solenoid (3.0 T long flattop). H-

  20. Proton “cannon” of the atomic H injector. The source produced 4 A ! pulsed proton current at 5.0 keV. Ion Optical System with “geometrical focusing”. Polarized H- ion current ~10 mA , P=85-90%. Unpolarized H- ion current ~ 300 mA of a very high brightness

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