STATUS of the DAFNE OPERATION and SHORT TERM PLANS

1. STATUS of the DAFNE OPERATION and SHORT TERM PLANS A. Gallo, LNF-INFN on behalf of the DAFNE Team

2. OUTLINE • 2002 runs results (brief summary) • 2003 Shutdown: Hardware upgrades • Status of the FINUDA run • Performances expectations • Short term plans

3. 2002 DEAR & KLOE LUMINOSITY Peak Daily Integrated Total Integrated

4. KLOE Integrated luminosity in the last 3 years

5. 2003 MAIN HARDWARE ACTIVITIES • FINUDAdetector & IR Installation • KLOEnew IR installation • Straight long sections and kickers modifications • Scrapers modifications • Bellows modifications • Ion clearing electrodes modifications • Wigglers modifications • Pipe modifications for RF 3rd harmonic cavity insertion

6. NEW INTERACTION REGIONS • New IRs forKLOEandFINUDAhavemodified optics (doublet configuration) in order to decrease the IP b functions and lattice chromaticity, optimize background rejection and new supports to provide variable quadrupole rotations, to operate at different detector magnetic fields (from 0 to maximum) 100 bunches operation should be possible in both IRs now

7. KLOE NEW INTERACTION REGION new Be chamber QD QF new vacuum chamber QF PCB quad & Air dipole QD 1/2 QF added

8. STRAIGHT SECTIONS MODIFICATIONS • “LONG” straight sections, where beams are injected, have been modified in order to: • Improve injection efficiency • Decrease injection sensitivity of the stored beam • (kick angle and kick duration both reduced by 50%) • Reduce dispersion at the septum • Optimize optical functions and phase advance in • the section to improve dynamic aperture

9. Straight Sections Mods Straight Sections have been completely dismantled and rearranged. 4 quads+2 sexts have been added

10. NEW ION CLEARING ELECTRODES About 50% of ICE broken due to faulty welding. Most of the ICE replaced with welding-free electrodes

11. EFFECT OF ICE ON BEAM ICE ON ICE OFF Sep 25th 2003 , I = 50 mA, filling = 60/120, P ~ 10 nTorr

12. WIGGLERS MODIFICATIONS • A new wiggler (arrived at LNF beginning of 2003) has been used to map the magnetic field and to study the pole modifications in order to improve the field quality • Once the final profile defined, all wigglers (8) have been modified accordingly • According to tracking simulations, the dynamic aperture and lifetimes should double

13. Wiggler field modifications Sextupole component Old wiggler: reduction of the dynamic aperture due to: • Strong sextupole components (~x2 like) • Field roll off at large offsets (~x6 like)

14. Terminal Pole Modifications Sextupole component One of the two terminal 1/2 poles has been modified in order to INCREASE its sextupolar component (F). This operation should improve the dynamic aperture. Overall non linearities should be largely reduced

15. Horizontal dynamic aperture with original wigglers Each track is a 2s contour in the horizontal phase space for on energy and off energy (0.8%) particles

16. Horizontal dynamic aperture with modified wigglers • On energy improvement mainly due to F sextupole added on the terminal ½ pole • Off energy benefits from better central poles and end-pole sextupole(reduction of the aperture is only due to the residual wiggler non-linearities)

17. ADDITIONAL UPGRADES AND MODIFICATIONS • Increasedhorizontal feedback power (= vertical one) • Removed one injection kickerper ring (2 kickers/ring remain), removed two valves and two bellows in each IR to further reduce ring impedance • Found (in the last days of theDEARrun) and repaired thecause of the e- current limit: faulty injection kicker • Found a faultypower supply and bend coil, responsible of an horizontal instability of the positron beam • 3rd harmonic RF cavitybuilt (but not yet installed) to add bunch-lenght tunability and RF energy acceptance

18. UPGRADES AND MODIFICATIONS (cont’d) • New cameras for theSynchrotron Light Monitorfor better emittance diagnostic • New electronics for theTransfer Lines BPMsto read position and optimize the beam transmission in non-invasive mode • 50 Hz linac operationin order to inject positrons at 2 Hz (electron injection is at 2 Hz already) • New (custom)Helium transfer linesto cool the solenoidal compensators with the existing crio-plant

19. STATUS of the FINUDA RUN (+ some history): • Hardware installation completed by July-4th (instead of May10) • Bug Fixes from old and new hardware by July-12th, beams make ½ turn in the rings • Run stopped because water-shortage in the Lab (spring dried out) • Operation resumed on August-27 (increased water flow,water barely enough to run) • Rings have been commissioned with the new layout and optics • Beam pipe has been conditioned to decrease the vacuum from initial 10-5 to operational 10-9 (dynamic) • Coupling has been corrected from initial 50% to less than 1% for both beams • Orbits have been corrected minimizing corrector strengths • 1.3 A electrons, 600 mA positrons (TFB limited) have been stored in single beam mode • 1st collisions in Finuda in October 13 evening • 1 pb-1 of daily integrated luminosity surpassed in November 2

20. Machine Operation Restart: a Week by Week History FINUDA RUNs COMMISSIONING and CONDITIONING WATER FAULT 1 turn in the ring 1st Finuda collision 1pb-1/day surpassed stored beams 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 Nov September October July August Bugs fixing and Maintenance

21. Machine Conditioning

22. model measurement Machine Commissioning: b Measurements DAΦNE lattice for collisions on FINUDA (Oct, 11th 2003) e+ Qx+ = .149 Qy+ = .210

23. model measurement Machine Commissioning: Dispersion Measurements e+ ac model = 0.0196; ac meas = 0.0186

24. Machine Commissioning: Coupling correction progress Positron beam, Oct. 23 Positron beam, Sept. 18 data from e+ Response Matrix

25. Machine Commissioning: Coupling correction progress Electron beam, Oct. 23 Electron beam, Sept. 17 data from e- Response Matrix

26. Machine Commissioning Coupling correction progress: spotsizes @ SLM Positron beam, Nov. 13 Electron beam, Nov. 13

27. Machine Commissioning Beam Decoherence Measurements Sext off: c11 = -426 Sext on: c11 = -115 (23/10/2003)

28. FINUDA Delivered Luminosity Oct. 22, 2003 Oct. 13, 2003 uncalibrated

29. FINUDA Delivered Luminosity uncalibrated Nov. 2, 2003

30. -1 [pb ] [pb ] -1 FINUDA RUN SUMMARY -1 [pb ] [pb ] -1

31. SOME FINUDA SELECTED EVENTS from V. Lucherini

32. SOME FINUDA EARLY RESULTS from V. Lucherini

33. A FINUDA HYPERNUCLEAR EVENT from V. Lucherini

34. PERFORMANCE GOAL for FINUDA • Number of bunches per beam 110 + 110 • Total current per beam e-/e+ (A) ≈ 1.0/1.0 • Peak luminosity (cm-2s-1) 1.0 x1032 • Luminosity lifetime (h) ≈ 1.2 • Number of fillings per hour ≈ 1.5 • Injection frequency e-/e+ (Hz) 2/2 • Data acquisition during injection ON • Delivered luminosity per day (pb-1) 3

35. PERFORMANCES GOAL for KLOE • Number of bunches per beam 110 + 110 • Total current per beam e-/e+ (A) ≈ 2.0/2.0 • Peak luminosity (cm-2s-1) 2.0 x1032 • Luminosity lifetime (h) ≈ 1.2 • Number of fillings per hour ≈ 1.5 • Injection frequency e-/e+ (Hz) 2/2 • Data acquisition during injection ON • Delivered luminosity per day (pb-1) 10 • Note: goals based on extrapolations of 2002 results and the new low-b IRs. All other upgrades are meant just as safety margins

36. 2003-2004 PLAN • FINUDA started data taking mid-October, for 4 months (or more if luminosity is low) • Goal: Deliver > 250 pb-1 • WhenFINUDA phase-1 program will be completed (Feb. 29, 2004), roll-out detector (~one week) to easy installation of new targets and allow “one low-b” optics, much more suitable for best KLOE performances • Resume KLOE data taking (March 2004) for a long(12 months), continuos run. • Goal: Deliver > 2 fb-1

37. Going beyond... what we would like to play with (but don’t count on it !) • Try to further improve the specific luminosity  minimize the beam blow-up due to beam-beam effects • Explore different working points much closer to the integer or half-integer, were the predictions show almost no-blow-up.Such WP have been adopted by the other Factories • Reduce bunch length(from 20 mm down to 15 mm) - and consequentely by - by changing sign to the momentum compaction

38. Going beyond... (cont’d) • For all these points it is essential to reach the predicted dynamic aperture, that is strongly affected by the non linearities in the near-integer tune space. • Moreover in a non blow-up regime, the lifetimes are consequentely smaller (Touschek limited) • If the machine can operate in such areas, a further factor of 2 is predicted by tracking codes, and an additional factor of 2 if the bunch can be shortened • We do not expect such order of magnitude of improvements, but we do have clear theoretical and experimental indications (PEP-II & KEK-B) that this could be a very promising approach to higher luminosities

39. SB Luminosity vs Qx and Qy DAFNE WP: e- 0.11/0.15 (Qx/Qy) e+ 0.15/0.21 L~ 2x1030(predicted and achieved) KEK-B WP: e- 0.52/0.56 e+ 0.52/0.59 PEP-II WP: e- 0.52/0.62 e+ 0.52/0.57 Possible new DAFNE WP: 0.06/0.14  L > 4x1030 and if sz<15 mm (with ac < 0) L > 6x1030

40. CONCLUSIONS • DAFNE operation has been resumed since July 4th, with about 8 weeks delay respect to the original shutdown schedule. From July 20th we got additional 5 weeks stop for water shortage in the Labs. • FINUDA data taking has started in October 13, and since then about 5 pb-1 have been delivered. • The machine performances are progressing but they are not yet at the desired level. A maximum integrated Luminosity of 1.2 pb-1/day has been obtained, while our goal is 3 pb-1/day. • The remaining machine optimization is mainly related to current increase and further coupling correction. • Background seems to be an issue mainly during injection. Measures to reduce it by trajectory and collimator optimization are under way. • At 3 pb-1/day rate a total 250 pb-1should be delivered to FINUDA by Feb. 29, 2004. At that point FINUDA detector will roll-out and KLOE data taking will be resumed after a brief shutdown.