1. W. Scandale 1 Status of UA9 Walter Scandale CERN CC09 5 th workshop on crystal channeling 24-27 March 2009

2. W. Scandale 2 Outlook  The crystal collimation concept  Lessons from H8RD22  The UA9 layout  What is already installed.  Plans  Conclusions

3. W. Scandale 3 Two stage collimation in a circular collider Secondary halo p p e  Primary collimator (scatterer) Beam Core Shower Primary halo (p) Secondary collimator (massive absorber) ~ L How it works ?  Short scatterer deflects the primary halo (ap. r 1 =N 1 √β TWISS ε)  Long collimator intercepts the secondary halo (ap. r 2 =N 2 √β TWISS ε)  halo particles captured through amplitude increase via multiple scattering and multi- turn effect. r1r1 r2r2

4. W. Scandale 4 p Beam propagation Primary halo (p) Absorber  Coherent deviation of the primary halo  Larger collimation efficiency  Reduced tertiary halo Crystal Crystal collimation Beam Core E. Tsyganov & A. Taratin (1991)

5. W. Scandale 5 Particle-crystal interaction d U Volume reflection Prediction in 1985-’87 by A.M.Taratin and S.A.Vorobiev, First observation 2006 (IHEP - PNPI - CERN) Possible processes:  multiple scattering  channeling  volume capture  de-channeling  volume reflection

6. W. Scandale 6 Rotation angle (µrad ) Angular profile (µrad) 1 -“amorphous” orientation 2 -channeling (50 %) 3 -de-channeling (1 %) 4 -volume capture (2 %) 5 -volume reflection(98 %) Angular beam profile as a function of the crystal orientation 11 3 4 2 5 The particle density decreases from red to blue The angular profile is the change of beam direction induced by the crystal The rotation angle is the angle of the crystal respect to beam direction 9mm long Si-crystal deflecting 400GeV protons (peak efficiency) W. Scandale et al. PRL 98, 154801 (2007)

7. TAL UA9 The underground experiment in the SPS Approved by the CERN Research Board of the 3 Sept 2008 CERN INF N PNPI IHEP JINR SLAC FNAL LBNL Goals:  Demonstrate loss localization  Measure channeling and collimation efficiency  Measure the single particle dynamics (later ?)

8. UA9 layout tank IHEP tank RP1RP2 TAL (tungsten) 600x30x30 mm 3 Installed

9. RD22 tank

11. RD22 goniometer

12. RD22 tank with goniometers and thin target

13. crystals

14. Crystal alignment table

15. Layout of the RD22 tank Beam axis Single strip crystal Quasi mosaic crystal Horiz. scraper 1mm W 30x30 mm 2 Quartz Cerencov detector Laser table for crystal alignment Multi Crystal cables Multi Crystal cables Multi Crystal cables GEMGEM GEMGEM Scintillating counter

16. TAL (secondary collimator)

18. RP1 (the CERN roman pot)

19. RP 2

20. Beam loss and scintillator counters C1C1 C2C2 C3C3 C4C4 BLM

21. The SPS beam We selected two energies of interest: –120 GeV, as for the RD22 experiments (reference data in the literature); –270 GeV, as for other planned experiment in the SPS (faster setting-up) High energyunbunchedbunched RF Voltage [MV]1.50 Momentum P [GeV/c]270120 Tune Qx26.13 Tune Qy26.18 Tune Qs0.002100.004 normalized emittance (at 1  ) [mm mrad]1.5 transverse radius (RMS) [mm]0.6711 momentum spread (RMS)  p/p2 to 3  10 -4 4  10 -4 Longitudinal emittance [eV-s]0.4  0.40.4 alternative tunes are those selected in RD22 (Qx=26.62, Qy=26.58).

22. The SPS beam Intensity a few 10 11 up to a few 10 12 circulating particles. Beam either unbunched or bunched in a few tens of bunches. Beam lifetime larger than 80 h, determined by the SPS vacuum. A halo flux of a few 10 2 to a few 10 4 particles per turn, which can be investigated with the detectors in the roman pots evenly distributed along the revolution period (unbunched beam); or synchronous to the bunch structure (bunched beam). Larger fluxes up to a few 10 5 particles per turn, which should be studied using only the beam loss monitors. Beam footprint in the crystal

23. QF518 QF520QD519 taratin Deflected beam Particle trajectory with α =150 μ rad

24. Expected efficiency for α=150  rad amorphous orientation Optimal orientation for channeling VR (-  ) positionangle TAL hit Probability to hit the TAL and RP2 Probability to hit the TAL Probability to hit the TAL, PR1 and RP2

25. Plans for 2009 UA9 First run: June 09 Loss localization experiment by Sept 09 Efficiency measurement by Nov 09

26. W. Scandale 26 Conclusion  Infrastructure ready (cables, mechanics, beam loss monitors, RF noise, Beam intensity monitors)  Basic hardware installed (Tank, two gonioneters, two crystals, TAL)  Detectors in progress  Already installed: 1 cerencov  To be installed this week: 6 scintillators, 3 GEM, 1 si-strip, 3 BLM  To be installed possibly in May: 1 cerencov, 2 scintillators, a fibrometer, more si-strip UA9 ready to start crystal collimation tests in June 09