The PEP-II Accelerator Status and General Plans

1. The PEP-II AcceleratorStatus and General Plans John T. Seeman Assistant Director of the Technical Division Head of the Accelerator Department SLAC SPC Meeting December 3, 2004

2. Topics • Highlights of Run 4 of PEP-II • Summer 2004 down • General future plans

3. Contributors to PEP-II • SLAC • LBNL • LLNL • With help from: • IHEP, Beijing, China • BINP, Novosibirsk, Russia • INFN, Frascati, Italy • CEA, Saclay, France • IN2P3, Paris, France • Caltech • BNL • Many people from the BaBar Collaboration • Visitors from CERN, DESY, Cornell, FNAL, KEK, …

4. PEP-II e+e- Collider BaBar Detector • Use the SLAC linac as upgraded for the SLC for the injector. HER RF 476 MHz LER RF 476 MHz Feedbacks Diagnostics 3.1 GeV positrons x 9 GeV electrons C = 2200 m

5. PEP-II HER RF cavities

6. PEP-II Interaction Region Components near BaBar LER HER BaBar Collision point

7. PEP-II Machine Advisory Committee Reviews • PEP-II Machine Advisory Committee • 1) Jan 4-6, 1995 • 2) August 24-25, 1995 • 3) April 11-13, 1996 • 4) January 6-8, 1997 • 5) November 10-13, 1997 • 6) December 14-16, 1998 • 7) October 9-11, 2003 • 8) April 15-17, 2004 • 9) December 13-15, 2004

8. Improvements in FY2004 • Peak luminosity: 6.6 9.21033 • Number of bunches: 1050 1588 bunches • by-2 pattern (24 long mini-trains) with 2% ion gap • Parasitic collision effects seen but small(<5%) • Electron Cloud (ECI) effects are small (<2%) • I+ current 1500 2450 mA (3 RF stations) • I- current 1050 1550 mA (8 RF stations) - by* of 12 11 mm • All data now taken in trickle charge mode • Both beams: LER in November, HER in March

9. Daily Integration Record with Trickle Injection 710/pb Luminosity LER I HER I

10. Peak luminosity of 9.21 x 1033 Record Peak Luminosity

11. Best shift, no trickle Nov 2003 Best shift, LER only trickle Mar 2004 Best shift, double trickle PEP-II Lumi HER current LER current Trickle injection at the B Factories PEP-II: ~5 Hz continuous KEKB: at ~5-10 min intervals

12. Trickle Charge: Length of Fill

13. PEP-II Run Time Dist. FY 04 M. Stanek Pre-trickle LER-trickle Double-trickle

15. PEP-II Performance Measure: Peak Luminosity

16. Run 4 Run 3 Run 2 Run 1 Design Performance CD4

18. Total >240 fb-1!

19. Summer 2004 PEP-II Improvements • IR2 south forward shield wall: Backgrounds • Add another new LER RF station: Higher current • Add a HER RF station by splitting up a current 4 cavity station into two 2 cavity stations: Higher current • Two new “Frascati” longitudinal kickers in LER: More stability • New electrodes for transverse kickers: More stability • Add fans to all HER bellows: Cool Higher Order Modes (HOMs) • Alignment work (quadrupole rolls): Smaller vertical emittance • New LER synchrotron light monitor: Smaller vertical emittance • IR NEG pump HOM reduction: Better lifetime and backgrounds • New Support Tube Chiller: Higher currents

20. New IR2 Shield Wall for BaBar IFR

21. LER NEG Test chamber

22. 350 °F LER NEG Pump Temperatures Lab test data of NEG outgassing as a function of temperature Upstream LER side

23. Existing 3082 chamber Quad extrusion BPM Cooling bar BPM NEG plenum Chamber support NEG heater

24. SiC HOM absorber Chamber shown inverted and plenum not shown for clarity

25. New bellows design with HOM absorber Kurita Novokhatski Weathersby

26. IR Vacuum Chambers Q1/Q2 Bellows Vertex Bellows

27. VTX Bellows Cooling Installation

28. Forward VTX BLWS Cooling

29. Thermo Model (May 2001) for 100 Watts Power input behind fingers.

30. New Be bellows design Cooling SiC

31. HER Single-Bunch Synchroscan Data at 16 MV

32. Comparing Single-Shot and Synchroscan Data LER e+

33. New LER Synchrotron Light Monitor Improved resolution Single bunch capabilities

35. Luminosity versus Crossing Angle Without parasitic crossing With parasitic crossing

36. Luminosity Equation • xy is the beam-beam parameter (~0.065) • Ib is the bunch current (1 to 3 mA) • n is the number of bunches (~1600) • by* is the IP lattice optics function (vertical beta) (10 mm) • E is the beam energy (3.1 and 9 GeV) • Luminosity (1033 cm-2 s-1)

37. Future luminosity increase factors

38. Overall Parameters and Goals Twice design Over five times design! Over three times design

39. PEP-II Future Luminosity Parameters

40. Expected PEP-II Delivered Integrated Luminosity

41. Future Maintenance Down Activities • Install LER-5 RF station • Install HER-10 RF station • Remove support tube for SVT work to fix radial ion pump and add an IR BPM • Upgrade several high-power IR vacuum chambers (Be bellows, Q4, Q5, high power dump, Q2 bellows, LER abort window, straight section bellows …) • HER lattice upgrade for lower momentum compaction and shorter bunches • New RF comb filters • New klystron linearizer • New transverse digital feedback processors

42. Conclusions • PEP-II has reached a luminosity of 9.21033/cm2/s. • PEP-II has delivered 710 pb-1 in one day. • PEP-II has delivered over 117 fb-1 in Run 4! • PEP-II has delivered over 256 fb-1 since May 1999. • Trickle injection in both rings all of the time. • Near term upgrades are going well. • Planned upgrades toward 2.31034 are on track. • Progress on studying a Super-B-Factory.