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DAFNE UPGRADE

DAFNE UPGRADE. DA F NE Upgrade Team. Scientific Committee-May 14-15, 2007 LNF - Italy. Crabbed Waist in 3 Steps. Large Piwinski’s angle F = tg( q)s z / s x Vertical beta comparable with overlap area b y s x / q Crabbed waist transformation y = xy’/(2 q ). P. Raimondi, November 2005.

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DAFNE UPGRADE

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  1. DAFNE UPGRADE DAFNE Upgrade Team Scientific Committee-May 14-15, 2007 LNF - Italy

  2. Crabbed Waist in 3 Steps • Large Piwinski’s angle F = tg(q)sz/sx • Vertical beta comparable with overlap area bysx/q • Crabbed waist transformation y = xy’/(2q) P. Raimondi, November 2005

  3. Crabbed Waist Advantages • Geometric luminosity gain • Very low horizontal tune shift • Large Piwinski’s angle • F = tg(q)sz/sx • 2. Vertical beta comparable • with overlap area • bysx/q 3. Crabbed waist transformation • y = xy’/(2q) • Geometric luminosity gain • Lower vertical tune shift • Vertical tune shift decreases with oscillation amplitude • Suppression of vertical synchro-betatron resonances • Geometric luminosity gain • Suppression of X-Y betatron and synchro-betatron resonances

  4. Parameters used in simulations L => 2.2 x 1033 cm-2 s-1

  5. SIDDHARTA IR Luminosity Scan Crab On --> 0.6/q Crab Off Lmax = 2.97x1033 cm-2s-1 Lmin = 2.52x1032 cm-2s-1 Lmax = 1.74x1033 cm-2s-1 Lmin = 2.78x1031 cm-2s-1

  6. Dynamic Aperture D.Shatilov, M.Zobov Dynamic Aperture tune scan Luminosity tune scan

  7. Off Energy Dynamic Aperture D.Shatilov, M.Zobov

  8. Beam Lifetime Comparison between Siddharta and FINUDA lattices for the same beam parameters RF 1% No scrapers Touschek lifetime is evaluated taking into account vacuum chamber aperture but no dynamic aperture S. Guiducci

  9. Trajectories of Touschek particles generated all along the ring that get lost at the IR Simulation shows how collimators strongly reduce background at the IR SCHPS101 SCHPL201 SCHPL110 IP SCHPL101 SCHPS201 Set of scrapers minimizing IR background SCHPL101 = 8.5sx = 11 mm (moved at s = -8.2 m from IP) SCHPL110 = 18sx = 18 mm SCHPS201 = 21 sx = 21 mm (moved at s = -44 m from IP) M. Boscolo

  10. Beam lifetime as a function of the scraper’s aperture S. Guiducci

  11. New Crossing Regions Layout • remove splitters (on both interaction regions) • new vacuum chambers for IP regions • adjust dipole fields and position (Blong lower, Bshort higher - splitters power supplies) • new permanent magnets in the IP1 region • readjust all the other elements (quads, sexts etc) • new components construction (kickers, bellows, diagnostics, etc) • new vacuum system for IP regions

  12. New beam line Crossing Region layout cont. IP QF1s QD0s

  13. Large Crossing Angle and Crabbed Waist Scheme

  14. Large Crossing Angle and Crabbed Waist Scheme

  15. S. Tomassini et all.

  16. 150 W F.Marcellini and D. Alesini mode1 mode2 mode3 mode4 • Aluminum made (very cheap) • Thin window thickness= 0.3 mm • Mechanical and Vacuum test done • Construction in progress permanent SmCo quads

  17. new compensator position, will not installed in SIDDHARTA setup new pumping system needed to replaceprevious slitter pumping system power new bellows

  18. New Shielded bellows Axial working stroke = ±5 mm Radial offset = ±3 mm • HFSS simulation • Beam excited fields in the bellows structure • No significant fields in the volume beyond the shield F.Marcellini, G. Sensolini

  19. tilted and separately powered dipoles bellows crab sextupoles compensator

  20. “half moon” chamber complete beam separation shape to fit inside existing quads

  21. IP2 Y is completely symmetric to IP1 except forcrab waist sextupoles and compensator

  22. New Injection Kickers New injection kickers with 5.4 ns pulse length have been designed to reduce the perturbation on the stored beam during injection VT VT 3 bunches 50 bunches t t present pulse length ~150ns (old kickers) FWHM pulse length ~5.4 ns • Expected benefits: • higher maximum stored currents • Improved stability of colliding beams during injection • less background allowing acquisition on during injection F. Marcellini, D. Alesini, G. Sensolini , S. Pella

  23. Fast Kickers • Kicker prototype preliminary test performed • Kicker final design completed • Pulse generator prototype under test (80 hours tested @3Hz done) • 50 KV final feedthrough will be tested next week • Delivery of the first Kicker by the end of May • Engineering of pulse system supply and controls implementation already order to the manufacture • Improved pulser version by the end of May • Remote controls implementation for August F. Marcellini, D. Alesini, G. Sensolini, S. Pella

  24. VACUUM CHAMBER modifications • 80 m long of storage ring reshaped (40% of DAFNE storage ring) • 70 m long of new vacuum chambers designed and under manufacturing • Designed new shielded bellows • Vacuum plant upgraded; quotation for new pumping units in progress • New fast kickers manufacturing in progress

  25. SIDDHARTA Kaon monitor bhabha monitor gamma monitor lead shield focusing quads SIDDHARTA Setup

  26. Machine luminosity monitors and IP diagnostics tool • e+ e- e+ e-g (8.5e-26 cm-2s-1@E>100MeV, 95% 1.7mrad)e+ e-  e+ e- Z g (<10% background) • e+ e-  e+ e-g g (6.6e-29 cm-2s-1@E>100MeV, 15% 1.7mrad)now limited by accidentals (@10^32 and chamber vertical acceptance) • e+ e-  e+ e-Bhabha scattering - more clean process312.5 Hz @ 18o<q<27o @ 1033cm-2 s-1 F. Bossi, P. Branchini, B. Buonumo, G. Mazzitelli, F.Murtas, P.Valente DAFNE-KLOE collaboration with the support of SSCR

  27. Luminosity monitor for SIDDAHRTA run TILE CALORIMETER g MONITOR PbWO4 crystal GEM RING

  28. Tile Bhabha calorimeter (lumi) • 4 calorimeter composed by 5 30o sectors • 7 lead sheet 5mm - 3 final lead sheet 10mm • 12 30o scintillating tile for sector • 3 WLS each tile • 1 PM for any sector (20 PM) • 12.5 X0 15% resolution @ 510 MeV • First tail Russian sample arrived • WLS installed and light emission tested • BTF test planed for October • PM, Electronics and DAQ by KLOE

  29. A 3GEM Monitor for DAFNE rectangular GEM prototype under test @ DAFNE 10 cm 2.4 cm Annular gem foil design for bhabha detector@ DAFNE 2.4 cm 64 pads 10 cm The read out has been realized using 8 chip ASDQ (8 channel each) Test at BTF 99% efficiency for electron (signal in bhabha measure) ~ 1% efficiency for photons (background in bhabha measure) 32 + 32 channels

  30. 3GEM monitor test on DAFNE On April 2007 the 3gem chamber has been put at zero degree on DAFNE for photon detection coming from the FINUDA interaction region e - 3GEM e + lead beamstrahlung g number of photon vs timeand FINUDA luminosity photon spot-size

  31. Order Status Progress …

  32. Time line

  33. Time line

  34. LHC Upgrade

  35. spare

  36. DAFNE-UP & KLOE

  37. DAFNE-UP & FINUDA

  38. Luminosity and crossing angle + crossing angle q (Piwinski angle F) luminosity is limited by hourglass and tune-shift effects high density N low by low sx y y by by z z The introduction of a crossing angle do NOT improve luminosity

  39. luminosity and tune-shift bat allows to play with transversal dimension sx and by optical function, kipping limited the vertical tune-shift and strongly depressing horizontal tune-shift • sz large sx small bat a large Piwinski angle can generate strong sincro-bethatron oscillation

  40. Suppression of X-Y Resonances Horizontal oscillations sextupole • Performing horizontal oscillations: • Particles see the same density and the same (minimum) vertical beta function • The vertical phase advance between the sextupole and the collision point remains the same (p/2)

  41. Increase Positron Current • New Injection Kickers • New Feedback Systems • Ti-Coating

  42. Optical Function

  43. Wiggler linearization CURVED POLE Reduction of the octupole around the beam trajectory in the region of the poles Proposed by Pantaleo MOVING MAGNETIC AXIS Compensation of the integrated octupole in each semiperiod S. Bettoni 28/3 New method

  44. Shifted Poles Model S. Bettoni 28/3 For the moment shifted the coils with the poles

  45. Analysis of the results: comparison with the experimental data S. Bettoni 28/3

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