T-980 Crystal Collimation Recent Results T-980 Collaboration: FNAL, SLAC, BNL, CERN, PNPI, IHEP, INFN D. Still CM14 April 27, 2010

C14 April 27, D. Still2 Overview: Brief T980 History and Purpose Experimental Setup Initial results from Multiple Volume Reflection (MVR) Comparison of MVR results with simulations Summary

C14 April 27, D. Still3 Explanation of Crystal Channeling Ray Fliller- Halo

C14 April 27, D. Still4 Vertical Multi-Strip Orientation This orientation is opposite of what was calculated and estimated. Name: MS Bend: 63urad (VR) 8 strips

C14 April 27, D. Still5 Overview: Brief T980 History and Purpose Experimental Setup Initial results from Multiple Volume Reflection (MVR) Comparison of MVR results with simulations Summary

C14 April 27, D. Still6 T980 Setup in Tevatron E0 for Bent Crystal E03H Collimator Channeled Beam Path Volume Reflected Beam (VR) Path F172H Collimator B0 E0 F1 D0 Vertical m m 27.8 m F1 detectors Abort gap (T:F1LABT) Bunch (T:F1LBNC) Pin detector (T:LE0PIN) Detectors Abort gap (T:E1LABT) Bunch (T:E1LBNC)

C14 April 27, D. Still7 New Vertical Goniometer Up and Downstream Laser angle measurement instruments Up and Downstream Motion control and LVDT

C14 April 27, D. Still8 New Characterized Crystals Name: O-BNL-02 Bend: 410urad Miscut: 1600 urad Name: MS Bend: 63urad (VR) Name: O Bend: 360urad Miscut: 120urad Installed Ver Dnstrm goniometer Installed Hor goniometer Installed Ver Upstrm goniometer

C14 April 27, D. Still9 Goniometer Installations over Summer 09 Shutdown Newly built and installed (Summer 2009) Vertical goniometer at E0. It is ~ 4m upstream of the Hor. one. Ver. goniometer houses old O- shaped crystal (reversed for negative miscut) and multi-strip crystal. Modified horizontal goniometer. Replaced old large-miscut angle O- shaped crystal with new small miscut O-shaped during Summer 2009.

C14 April 27, D. Still10 Location of Vertical multi-strip CH & VR beam Bent Crystal E03v Collimator Volume Reflected Beam (VR) Path Channeled Beam (CH) Path F172v Collimator E0 F1 D0 Displacement of VR beam at E03 Collimator is +1.76mm Displacement of CH beam at Collimator is +6.0 mm

C14 April 27, D. Still11 Overview: Brief T980 History and Purpose Experimental Setup Initial results from Multiple Volume Reflection (MVR) Comparison of MVR results with simulations Summary

C14 April 27, D. Still12 MS Characterizations at Cern North Area RD22 H8, 400 GeV/C protons Name: MS Bend: 63urad (VR) Bend: 200urad (CH) 8 strips Crystal angle AM CH VR AM

C14 April 27, D. Still13 Vertical Multi-strip Angular scan CH VR AM E03V and F172V Collimators in at max catch

C14 April 27, D. Still14 VR beam collimated w/ E03V is consistent (only if F17 is in) (Analysis by Vladimir Shiltsev) VR beam displaced 1.76mm from core with a sigma of F172 collimator is in at max catch. 1.76mm displacement Corresponds to VR angle: θ=1.76mm/28m =63 urad Cern H8 measured angle: 93 urad/ sqrt(980/400)=59 urad Width is ~39 urad that’s wider than expected SPS: 18*sqrt(980/400) =29 urad.

C14 April 27, D. Still15 10/5/2015V.Shiltsev - T980 CH beam collimator scan w/ F172 collimator - (E03 is in) Angle of Bend for CH Corresponds to: θ=1.87mm/29m= 65 urad instead of 200 urad Width is ~28 urad that’s narrower? than expected (Analysis by Vladimir Shiltsev)

C14 April 27, D. Still16 10/5/ V.Shiltsev - T980 MS Crystal Angle Scan: LE0PIN Loss rate Calculated Efficiency=90% If CCVAD calibration coefficient is 1.24 θ=(CCVAD-500) *1.24 Total width ~550 urad High Eff width ~100 urad

C14 April 27, D. Still17 Overview: Brief T980 History and Purpose Experimental Setup Initial results from Multiple Volume Reflection (MVR) Comparison of MVR results with simulations Summary

C14 April 27, D. Still18 Simulated Data – S. Drozhdin “Beam Collimation in the Tevatron Using Multi-strip Protvino Channeling Crystal”

C14 April 27, D. Still19 Qualitative Look at Experimental vs. Simulated Data VR Beam collimated at E03V CH beam collimated at F172V CH peak also aligns Need better understanding of these areas. Align Good

C14 April 27, D. Still20 Losses at Crystal are not consistent with Simulation

C14 April 27, D. Still21 Experimental Data does not have loss at F0 Lambertson

C14 April 27, D. Still22 What is missing from Real data to Simulation????? Are there process that are not taken into account in simulation? Multi-turn effects, crystal problems, crystal inefficiencies, skewed planes, beam loss at additional apertures, physics missing from simulations????? The problem seems to be most wrong in the AM part of crystal, then next boundaries between VR and CH. Went back to Drozhdin paper to look in detail. Noticed that simulations are done for 20 turns. After talking with Sasha, once a particle is lost it is gone. Therefore number of particles is shrinking and it takes more (many more ) turns for a particle to be lost in the AM part. Therefore, we are not really estimating real data to simulation in area not in CH or VR. Sasha reran simulation to take AM with circulation beam.

C14 April 27, D. Still23 Modified original simulations to include estimate for multi-turn losses at amorphous angles

C14 April 27, D. Still24 Experimental and simulated losses at the crystal

C14 April 27, D. Still25 Experimental and simulated losses downstream E03 collimator

C14 April 27, D. Still26 Experimental and simulated losses downstream of F172 collimator

C14 April 27, D. Still27 Summary Demonstrated CH and VR with the vertical multi-strip crystal MS at 980Gev. Collimator scans measure the VR angle at E03V at ~ 63urad in good agreement with estimated crystal VR bend but some error from 59urad characterized at Cern H8. Collimator scans measure the CH angle at F172Vat ~ 65urad instead of H8 results of 200urad. Uncertain the cause of this error. In both VR and CH scans, both E03 and F172 need to be in to produce reasonable results. Qualitative comparison of experimental data and simulated data has better agreement when better multi-turn beam loss estimates for crystal angles in the amorphous angles were applied. Further simulations will be run with increased number of turns.