1. CRYSBEAM crystal extraction and detectors Gianluca Cavoto (INFN Roma) CERN Mar 16 th 2015

2. Outline  Efficient crystal extraction of a multi-TeV hadron beam  Demonstrate it is useful for fixed target experiments  The INFN CRYSBEAM(*) project  Develop a suitable crystal  Detectors for extracted beam monitoring  An application: Cosmic ray physics with the extracted beam (*) CRYSBEAM is funded by a ERC Consolidator Grant GA 615089 (FP7 IDEAS action) with a 2M euro budget for the period May 2014- May 2019 INFN is the Host Institution Website : http://crysbeam.roma1.infn.it/ 2/25G.Cavoto

3. The CRYSBEAM challenges: the crystal for extraction 3/25G.Cavoto

4. Critical Radius for channeling  Given a deflection angle Φ [~1 mrad] Φ = L/R where R is crystal curvature radius and L is the crystal length Effective potential in presence of centrifugal force (bending) Critical radius to have an efficient channeling 4/25G.Cavoto

5. Channeling efficiency versus Rc  ~1 mrad deflection requires ~12cm long Si crystal (or 7 cm long Ge crystal)  Much longer than what UA9 tested and used so far High efficiency zone R > 10 Rc E. Bagli et al., Eur. Phys. J. C (2014) 74:2740 Si (110): R c = 12m at p  = 7 TeV Ge (110): R c = 7m at p  = 7 TeV  Experiment (H8 and SPS):  Si bent crystal (L = 0.2cm)  (1 1 0) plane  400 GeV/c protons 5/25G.Cavoto

6. New bending technology  For a very long crystal (~10 cm), a new holder need be designed!  Large primary bending to generate anti-clastic bending  Assisted curvature with tensile layer deposition or ion implantation  Working on a intermediate length crystals beam UA9 LHC crystal Anticlastic curvature A.Mazzolari, V.Guidi 6/25G.Cavoto

7. Beam monitoring 7/25G.Cavoto

8. Radiator with position sensitivity  Ultra-fast high power laser writes waveguides!  Use to build quantum-optics device  “write” several optical waveguide to trap Cherenkov light (as a bundle of fibers)  Connect each waveguide to a separate light sensor (SiPM, APD,…)  Position information given by which channel fires  Instrumented beam silica thin window 8/25G.Cavoto

9. New concept: cutting holes Instead of writing the core of the planar waveguide in the glass, we remove the glass to create a low index cladding Advantages: Very high index change  Critical angle 43° (47° is totally reflected) @455nm No Cherenkov radiation is generated in the cladding  high SNR R.Osellame PoliMI-CNR 9/25G.Cavoto

10. Irradiation and chemical etching Irradiation: 1 kHz, 150 fs 5 µJ @ 800 nm 15 µm/s 0.3 NA 200 µm buried Etching: 20 % HF in water Ultrasonic bath 3 h time Irradiation: 1 kHz, 150 fs 5 µJ @ 800 nm 15 µm/s 0.3 NA 200 µm buried Etching: 20 % HF in water Ultrasonic bath 3 h time HF acid bath Waveguide Pre-etching irradiation Fused Silica Glass 10/25G.Cavoto

11. Sample with waveguide separation Front image Side image Scale bar 100µm No glass glass Planar waveguide 90µm:70µm 180µm:80µm White light transmission 11/25G.Cavoto

12. Test with laser light CW laser light @473 nm entering from the side face at an incident angle α Angle of incidence  ~45° corresponding to an internal angle with respect to z of ~61°. α z To be tested with 500 MeV electrons at BTF in Frascati 12/25G.Cavoto

13. Waveguide tapering  Matching SiPM size 5 mm straight 13 mm curved 0, 5 mm 1,2mm 3mm Glass thickness 2mm 0, 5 mm Particle beam Linear array of SiPM detectors Single SiPM 13/25G.Cavoto

14. Hadronic showers and Cosmic rays 14/25G.Cavoto

15. Ultra High Energy Cosmic Rays 15/25G.Cavoto

16. Hadronic interaction in air showers  Accelerator based experiments to unravel this (LHC-f, NA61 at CERN,…) G.Mitsuka (LHCf coll) 16/25G.Cavoto

17. CR Mass composition Shower maximum position Cross section Pierre Auger Observatory Data interpretation depends on MC used to described the shower 17/25G.Cavoto

18. Muon in cosmic air-showers More muons in air-shower data than expected Can be a problem in interaction physics in air-shower model ? Is a muon counting experiment after a beam dump interesting (or enough) to help solving this ? Do we need to study charm content of a shower ? Access to parton with momentum fraction x → 1 in the target. Study production of charm from light nuclei directly? 18/25G.Cavoto

19. Showers of Cosmic Rays in a lab  Sub-showers of UHECR air-shower can be reproduced in lab: compare with MC (CORSIKA)  Following shower evolution as in air-shower experiment! R.Ulrich  Hadron beam of 10 GeV – 10 TeV (both SPS and LHC)  Different targets (carbon, water, liq. nitrogen) 19/25G.Cavoto

20. Can be tested on SPS North Area were proton and pion beam are currently available (up to 400 GeV energy) Eventually moved to LHC (crystal) extracted line A smart absorber experiment  Dump the extracted beam onto a light element absorber.  Possibly change the absorber  Count the number of particles crossing thin active layers 150 cm 50 cm 10 c m 0.5 cm 20 cm 20/25G.Cavoto

21. Small TPC for track imaging The anode is a quad medipix without silicon sensor: The active area is 9 cm 2 The particle track is analysed with 512 pixel in length of 3 cm Gas flux Triple GEM Kapton window Particles to be analysed Length analysed F.Murtas 21/25G.Cavoto

22. GEMPix detector  Building a new version for CRYSBEAM  larger drift region  totally sealed (can be immersed in a water tank to measure p-O interactions) Particles from shower To be tested at BTF with internal graphite (HOPG) target. 22/25G.Cavoto

23. Example of track imaging F.Murtas – CERF H8 23/25G.Cavoto

24. Plans 24/25G.Cavoto

25. CRYSBEAM objectives for 2015  Test LONG crystal bending strategy  Use extreme bending to produce anti-clastic bending on 4 inch wafer  Test a 30mm long crystal in NA  Feasibility of silica micromachining for Cherenkov light collection  Test at LNF BTF in Apr/Oct  Test new Cherenkov light trasmission from vacuum to outside (see next talk)  Design a smart absorber  Test TPC – GEMpix with internal target (BTF/H8)  Design and build large and sealed TPC 25/25G.Cavoto

26. Additional back-up slides 26G.Cavoto

27. Germanium technology is mature alternative Plannar channeling efficiency Vertical Deflection [  rad] SPS-H8-CERN 400 GeV Proton De Salvador et al. JAP (2013) Horizontal Deflection [  rad] First axial channeling in Ge De Salvador et al. APL (2011 ) 27G.Cavoto

28. Silicon strip manufacturing a) Starting material: (110) silicon wafer b) LPCVD deposition of silicon nitride thin layer c) Silicon nitride patterning (photolithography) d) Etching of Si in KOH solution, silicon nitride acts as masking layer e) Silicon strips release f) Removal of silicon nitride Established fabrication technique Revisitation needed! 28G.Cavoto

29. Piezo-goniometer installed on LHC  Designed at CERN EN-STI group, realized by CINEL A.Masi New version under study Piezo-electric material with higher Curie point (>200 deg) under investigation Movable beam pipe section Stepping motor (linear movement) RF contacts On the beam pipe a copper and NEG coating could be applied Linear Stroke: 60 mm Linear resolution: 5 um Total angular range : ±10 mrad Angle resolution: 0.1 µrad Angle accuracy: ±1 urad Operational position Movable beam pipe section 29G.Cavoto

30. Crystal resistance to irradiation  IHEP U-70 (Biryukov et al, NIMB 234, 23-30)  70 GeV protons, 50 ms spills of 10 14 protons every 9.6 s, several minutes irradiation channeling efficiency unchanged.  SPS North Area - NA48 (Biino et al, CERN-SL-96-30-EA)  450 GeV protons, 2.4 s spill of 5 x 10 12 protons every 14.4 s, one year irradiation, 2.4 x 10 20 protons/cm 2 in total, channeling efficiency reduced by 30%.  HRMT16-UA9CRY (HiRadMat facility, November 2012):  440 GeV protons, up to 288 bunches in 7.2 μ s, 1.1 x 10 11 protons per bunch (3 x 10 13 protons in total) ➔ comparable to asynchronous beam dump in LHC no damage to the crystal after accurate visual inspection more tests planned to assess possible crystal lattice damage accurate FLUKA simulation of energy deposition and residual dose 30G.Cavoto

31. More on CR physics 31G.Cavoto

32. Development of a hadronic shower 32G.Cavoto

33. Conceptual experiments with absorber Segmented absorber Active layers (pixelated?) to measure shower properties Extracted beam target Q: are shower properties sensitive to cross section on absorber material? (test with FLUKA and SYBILL) “single-arm” detector Target material can be changed. Measure (in a narrow solid angle) exclusive cross-section (anti proton, B, C,..) Detector can be moved at different angles 1 2 33G.Cavoto

34. Conceptual experiments (2) Thin absorber 3 “diffracted particle” Dispersive region of the accelerator: Detected diffracted particles Use the accelerator as a spectrometer to measure the momentum of diffractive particles With two stations, measure angle and momentum Direct measurement of diffractive cross section on absorber materials Incoming flux detector 34G.Cavoto