1. January 15, 2005D. Rubin - Cornell1 CESR-c Status -Operations/Luminosity December/January vs September/October -Machine studies and instrumentation -Simulation and modeling

2. January 15, 2005D. Rubin - Cornell2 Peak Luminosity

3. January 15, 2005D. Rubin - Cornell3 Specific Luminosity

4. January 15, 2005D. Rubin - Cornell4 Integrated Luminosity

5. January 15, 2005D. Rubin - Cornell5

6. January 15, 2005D. Rubin - Cornell6

7. January 15, 2005D. Rubin - Cornell7 Machine Studies/Instrumentation Horizontal separator tilt Level measurements, tilt < 0.3 mrad, negligible effect on orbit But what about plate/vacuum can alignment ? Beam based measurement, tilt ~ 4 mrad Tune spread - Safe operating space in tune plane narrows with increasing current - Tune spread reduces current limit - Instability in magnet power supply? - Modify feedback circuit for all quad choppers, no effect on tune spread

8. January 15, 2005D. Rubin - Cornell8

9. January 15, 2005D. Rubin - Cornell9 Machine Studies/Instrumentation Orbit stability Evidence of vertical orbit motion in - synchrotron radiation light monitor - orbit measurement with beam position monitors - turn by turn data at IR beam detectors - fast luminosity monitor Sources of vertical motion might include - Instability in quadrupole power supplies (Q48,49) - of vertical separator plate voltages - of skew quadrupole currents, SCIR skew quads

10. January 15, 2005D. Rubin - Cornell10 Machine Studies/Instrumentation Continuously monitor electron positron orbit difference - BPM electronics and software under development “true” differences with arbitrary time scales - Better monitoring of suspect elements

11. January 15, 2005D. Rubin - Cornell11 Machine Studies/Instrumentation Luminosity monitor - Luminosity signal is compromised by lost particles when electron lifetime is poor - Detector segmentation provides means for correction DSP software begin developed - Plan to implement “true” calibration - Software also in the works to enable bunch by bunch luminosity measurement

12. January 15, 2005D. Rubin - Cornell12 Knobs to control differential coupling using skew sextupoles 3 new sextupoles installed Demonstrated capability to measure with turn by turn BPM data, coupling at IP - And “good” luminosity corresponds to measured flat beam at IP Developing IR BPM calibration and software to implement as part of coupling correction procedure Machine Studies/Instrumentation

13. January 15, 2005D. Rubin - Cornell13 SCMATING 2 = -160

14. January 15, 2005D. Rubin - Cornell14 SCMATING 2 = -120

15. January 15, 2005D. Rubin - Cornell15 SCMATING 2 = -70

16. January 15, 2005D. Rubin - Cornell16 SCMATING 2 = -40

17. January 15, 2005D. Rubin - Cornell17 SCMATING 2 = -120

18. January 15, 2005D. Rubin - Cornell18 SCMATING 2 = -70

19. January 15, 2005D. Rubin - Cornell19 SCMATING 2 = -40

20. January 15, 2005D. Rubin - Cornell20 SCMATING 2 = 70

21. January 15, 2005D. Rubin - Cornell21 SCMATING 2 = 40

22. January 15, 2005D. Rubin - Cornell22

23. January 15, 2005D. Rubin - Cornell23 Beam beam simulation Semi strong-strong simulation Machine model includes all individual guide field elements (RF, wigglers, separators,…) and nonlinearities radiation, damping, crossing angle, pretzel, parasitic interactions, … Weak beam ~ 200 macroparticles Track for 200,000 turns Use weak beam size to update strong beam -> Beams have equal charge and size Strong beam is fixed in space

24. January 15, 2005D. Rubin - Cornell24 Beam beam simulation 1.89 GeV/beam

25. January 15, 2005D. Rubin - Cornell25

26. January 15, 2005D. Rubin - Cornell26 -Real wigglers, -Linearized wigglers, -Pretzel off/real wigglers No significant difference In low current behavior Simulation

27. January 15, 2005D. Rubin - Cornell27

28. January 15, 2005D. Rubin - Cornell28 More bunches -10 bunches/train, 2 sets of 5 displaced by 2ns -Calculation of optical distortion due to parasitic additional interactions indicates small effect -Established injection of single 10 bunch train -Collisions of 2,3 electron bunches with 10 bunch positron train Alternatively 9 bunches/train 1 set 5 and 1 set 4 displaced 6ns under study Machine Studies/Instrumentation (cont)

29. January 15, 2005D. Rubin - Cornell29 Simulation plan Lattice with distributed radiation excitation Dependence differential offset/angle at IP coupling/ differential coupling sextupoles/chromaticity tune spread Thanks to CLEO collaborators Minnesota and Illinois and CHESS for making computers available and for help getting started

30. January 15, 2005D. Rubin - Cornell30