ERIK H.M. HEIJNE CERN, Geneva and IEAP of CTU in Prague MEDIPIX Collaboration

1. 3-D Pixel Imagers with Exploitation of Delta-rays in Precision Flow Tracking and Identification of Elementary Particles ERIK H.M. HEIJNE CERN, Geneva and IEAP of CTU in Prague MEDIPIX Collaboration 2014 Workshop on Intelligent Trackers 16 May U. Pennsylvania, Philadelphia

2. AcknowledgementsThanks to colleagues at CERN, at IEAP and at Nikhef for discussion and helpThanks for satellite data from ESA and Czech Space Research CenterThanks to co-authorsMichael Campbell and CERN team, Carlos Granja(IEAP), Claude Leroy(IEAP), Stepan Polansky (IEAP), Stanislav Pospisil (IEAP), Daniel Turecek (IEAP), Zdenek Vykydal (IEAP), Alan Owens (ESA ESTEC), Karim Mellab (ESA ESTEC) and Petteri Nieminen (ESA ESTEC)Special thanks for discussions with Suen Hou, Tjeerd Ketel, Sophie Redford, Enrico SchioppaJr

3. Imaging around the VertexSome different (old) ideas for future Detectorscertainly provocative, and simplistic keeping in mind nanometer electronics and 3D developments cloud chamber - emulsion - bubble chamber - wire chamber - silicon array

4. Particle Physics Old Times (2m Chamber CERN) 2 cm

5. Typical Muon Trails in Timepix ... T3-1500 bubble in BEBC 1mm T3-1504 T3-1507

6. TYPICAL TRAILS ... T3-1510 T3-1511 bubble in BEBC 1mm T3-1558

7. Photosensitive Emulsion as Detector Thick gelatine film 3D, sub µm precision with AgBr CHARM DECAY Photon exp.WA59 ~ 1985 50 µm Successive ionizing energy transfers (~5keV) to grains create latent image 500 µm

8. 55 µm 300 µm Si pixel Photosensitive Emulsion as Detector Thick gelatine film 3D, sub µm precision with AgBr CHARM DECAY Photon exp.WA59 ~ 1985 50 µm Successive ionizing energy transfers (~5keV) to grains create latent image 500 µm

9. Photosensitive Emulsion as Detector • Sub- µm Precision • COLLABORATIVE DEVELOPMENT with INDUSTRY (ILFORD – UK) • Thick Layers • > 200µm – 1mm • Stacks allow Larger Volume Cecil POWELL Following plates are from Handbook: Powell, Fowler & Perkins The Study of Elementary Particles by the Photographic Method, Pergamon Press 1959

10. Sequence of Ions Z=1...26 in Emulsion Energy deposit and also the delta ray frequency along the track proportional to Z2 50µm H 1 He 2 Li 3 Be 4 B 5 C 6 N 7 O 8 Ne 10 Na 11 Mg 12 Si 14 Ca 20 Ti 22 Fe 26

11. Delta electrons allow ion identificationCan they be specific also in other situations? Delta electron counting proposed by Powell. Fowler & Perkins The Study of Elementary Particles by the Photographic Method, Pergamon Press 1959

12. Arguments for imaging detector Tracking with many pixels (15-30) improves precision allows to exclude points corrupted by a d-ray possible to reach <0.1µm Reduction of ambiguities in reconstruction process proposed 2-point stubs help already, this goes further Additional information on particles: improved dE/dx Specific features identify energetic leptons (e , µ) transverse momentum, delta rays Sensitivity for exotic things e.g. clusters from neutrals, very low energy

13. Is there danger that we miss new phenomena? Clusters observed with Timepix pixel detector at 850km altitude in ESA Proba V mission SATRAM experiment 2013-2014 Most of these clusters can be explained as energetic heavy ions sometimes part of an nuclear interaction in upstream material

14. CERN SPS 80GeV/n Pb ion beam 2012 Pb ION with many delta rays energy loss mip in Si 280 eV per µm = 77 e- /µm Landau value in 0.3mm full loss is 380 eV/ µm relativistic Pb ion in Si x Z/A (=0.396) x z2 (=6724) 295 keV per µm = 81000 e- /µm trails are 76±1 pixels x 55.14 µm total energy deposit 3124 MeV rear-side glancing angular incidence, here 4.1 degree

15. Delta Electrons Emulsions: delta counting performed on 5keV delta’s: energy deposit per grain above ~50keV tracks are too long to be followed Bubble chamber: delta’s only visible if >MeV Microstrip detector: delta’s detectable only in lateral direction if kinetic energy >90keV cause undesirable double or multiple hits Timepix pixel detector: delta’s visible if kinetic energy >70keV >50µm range needed to escape from pixels along the trail pixel size is 55µm square

16. Ionization Energy Loss for m.i.p. in Si (with η) (a) Bethe Bloch (b) corrected for density effect (c) restricted loss η 500keV (d) Landau peak Heijne CERN Yellow Report 83-06 0.1 1 10 100 1000 10000 GeV/c momentum of muon

17. Ionization Energy Loss for m.i.p. in Si (with η) (a) Bethe Bloch (b) corrected for density effect (c) restricted loss η 500keV (d) Landau peak Increase by large transfers η= > ε > many of these appear as δ rays 500GeV/c Heijne CERN Yellow Report 83-06 0.1 1 10 100 1000 10000 GeV/c momentum of muon

18. Energy Loss for Minimum Ionizing µ in Si the factor k with z=1, for Si if β1 k = 0.0766 MeV cm2g-1 substitute =2.33 g cm-3 k = 179 keV cm-1 Energy loss liberates charge partially as d – electrons with transfers < < for a 100 GeV/c muon, simplified major term number of d‘s per cm of Si

19. Fraction of Energy Transfer into d Electrons in Si >10MeV >10MeV >10MeV increasing fraction goes into energetic delta electrons relevant for LHC large transfers along tracks

20. Electron Range in Si mm 100 10 1.0 20 pixels 2-4 pixels 0.1 1 pixel 0.01 0.001 pixel 55µm Graph adapted from Leroy-Rancoita ISBN 981-238-909-1 p.81

21. Delta Electron Generation 100GeV/c muon in Si a few SATRAM particles seem to have exceptional d frequency see later

22. Muon Energy Loss in Copper OVER 109 INTERVAL bg density effect Rev Part Phys 2006, Groom et al.

23. ~TeV particles may be found in high altitude cosmic raysTimepix pixel detector has been launched on 7 March 2013on ESA minisatellite PROBA Vorbit 800-900km ’SATRAM’ experiment >1 year of data frames online(Space Application of Timepix Radiation Monitor)

24. Observations on SATRAM involving delta electrons Space Application Timepix Radiation Monitor Launched 7 March 2013 Altitude ~820km (Low Earth Orbit) Carlos Granja Talk EPS Ravenna Workshop

25. Satram Cluster/Event with Trail and d electrons (?) a few more candidates

26. Deltas in Si two of the ‘apparent’ deltas may be in fact short m.i.p. s that overlap on the long track indicated with the arrow data from IEAP-CTU Medipix Monitoring web site

27. Satram: the Full Frame 32570 in reality complicated event ???? data from IEAP-CTU Medipix Monitoring web site

28. Another Satram Frame: November 2013 6 m.i.p. + ion coming out from satellite wide charge deposit by ion at rear of sensor due to diffusion delta’s point towards rear data from IEAP-CTU Medipix Monitoring web site

29. SATRAM frame on ESA PROBA V satellite Nov 2013 Many perpendicularly incident protons also 2 ions recognized by crown of d-rays axially symmetric data from IEAP-CTU Medipix Monitoring web site

30. SATRAM frame on ESA PROBA V satellite 31 December 2013 17.26.00 Particle showing enhanced frequency of d-rays low background trail length in Si 7.8mm see following enlargement data from IEAP-CTU Medipix Monitoring web site

31. SATRAM frame on ESA PROBA V satellite 31 December 2013 17.26.00 Particle nearly at 45° 3 d-rays multiple 7 single pixel d several more pixels have enhanced dE/dx

32. Can enhanced d Electrons indicate TeV Space Muons? Some indications, need more candidates The microscopic imaging capability proves very useful “MHz Emulsion” Experiment becomes possible Our particle physics imagers light-weight, “picosatellite <1kg”

33. 3D Stacked Pixel Imaging Unit 1 mm Spacer to achieve circle periphery 0.44mm 64 pixels 2.56mm total 3 mm 20.5 mm 512 pixels 40x40µm 200µm

34. Tentative Design for Inner Particle Imager LHC chip 64x512 pixels 40µm + periphery 3x20.5mm detector unit 1mm =2 layers ~200 units one ring of radial pixel assemblies sensor/readout chip is 20.5 x 3 mm one unit (1mm thick) is 4 chips r=30mm inner circle 200mm beam pipe services 2mm ? circle 220mm outer sensor circle 210mm slits10mm

35. Speculative Parameters Sensor Pixel Matrix: Pixel 40µmx40µm, thickness 200µm matrix 512x64 32768 pixels Readout Chip: Matrix idem as sensor, 20.5mmx2.56mm + periphery 400µm CMOS technology 32nm including TSV, thinned 40µm power per pixel 1µW (??) chip ~40mW Basic Unit 4-layer hybrid pixel detector: Thickness 1mm= 4x0.2 back-toback + 4x0.04 + spacers Power and data connections per basic unit of 1mm Basic ring, consists of 200 basic units = 800 chips + sensors: Circumference: Inner 200mm around beam pipe  60mm Outer circumference 220mm  70mm Width 20.5mm Thickness Rin-Rout 3mm Si + 2mm services (???) Power 800x40mW = 32 W need 20 rings to cover 41cm  >600W

36. Speculative Parameters Full Pixel System of 20 rings, 40cm long: Number of chips 20x200x4 =16 000 16 000 x 32768 = 525 000 000 pixels Overall layer structure: Basic Unit has 4x512 pixels of 200µmx40µm coverage is 200 x 2064 = 400 000 pixels per layer occupancy ~1% for 1000 interactions/average multiplicity 40 20% Insensitive area from readout chips and spacers, remedy could be to incline basic units 64 layers deep along the radius r=30mm Operational: Ultra-LHC 1000 collisons/crossing 40 000 tracks x 64 pixels generate 1010 carriers/10ns continuous signal current ~0.1A dark current ~equal 16 000 x 10µA = 0.16 A inner circle 200mm Highly speculative indeed, many mechanical and electrical issues.... What could be physics gains for such a system?

37. MHz Imaging & Flow Detector Relatively thick rings of tracking layer many pixels deep , sensitive over several mm can handle high particle density deep submicron precision Imaging allows recognition of different features may be most interesting close to primary collisions Need for experimental verification >100 GeV electron beam new Timepix3 just now operational, readout per cluster Still highly speculative option initial studies can be made in space experiments investigate principles, technology as well as analysis

38. CERN H6 40GeV/c IonTrails beam with A/Z=2.5 scale 3000 scale 100 Pixelman display software different trails with distinguishing signatures

39. Different IonTrails A/Z=2.5 Frame 2717 a a scale 1000 scale 4000 Pixelman display software for large energy deposition, wide trails with 'sarcophage' effect'

40. Different IonTrails A/Z=2.5 Frame 2717 a d e b f d d a c b scale 1000 scale 4000 for large energy deposition, wide trails with 'sarcophage' effect'

41. END

42. Extra Slides

43. Accelerator people seem not to mind to make Ultra-LHC (1000 collisions/crossing)Plainly reject, or think about this? Physics and Politics, increase of intensity may be main justification for longer-term operation of LHC 2030-2040 Horizon Can radiation levels be supportable at all? Indications for TeV-energy physics may be found in space cosmic radiation Please note: these statements are my personal view for this workshop, no endorsement by CERN is implied

44. Particle Physics Old Times (2m Chamber CERN) 2 cm

45. MUON ENERGY LOSS in Fe AT HIGH MOMENTUM DOMINATED by BREMSSTRAHLUNG

46. 1000 keV/mm 1 eV/µm 0.001 ELECTRON ENERGY LOSS in Si • Silicon IONIZATION EXCITATION BREMSSTRAHLUNG K-EDGE FLUORESCENCE 1 keV 1 MeV 100 GeV Electron

47. MUON ENERGY TRANSFER PROBABILITY in Fe IONIZATION up to ~100 MeV PAIR PRODUCTION >100 MeV BREMSSTRAHLUNG >20 GeV SUM of CONTRIBUTIONS ~1/E2

48. % CONTRIBUTIONS ENERGY LOSS in Fe CONTRIBUTIONS up to 100 GeV