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CNGS - CERN Neutrinos to Gran Sasso

CNGS - CERN Neutrinos to Gran Sasso. > “Neutrinos” and “Gran Sasso” > CNGS Schedule > Main components, installation at CERN > Neutrinos at CNGS (some numbers). A sincere “ THANK YOU ! “ to the many colleagues who are contributing,

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CNGS - CERN Neutrinos to Gran Sasso

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  1. CNGS - CERN Neutrinos to Gran Sasso >“Neutrinos” and “Gran Sasso” > CNGS Schedule >Main components, installation at CERN >Neutrinos at CNGS (some numbers)

  2. A sincere “ THANK YOU ! “ to the many colleagues who are contributing, at CERN and elsewhere, to the CNGS project

  3. elementary particles come inthreeflavors (LEP) (pistachio, chocolate, vanilla) electric charge: zero ! mass:very smallzero? interaction with matter: “very weak” “ the elusive particle “ Leptons electric particle charge e -1 ne 0 ------------------------------------ m -1 nm 0 ------------------------------------- t -1 nt 0 What are Neutrinos (n) ? + antiparticles

  4. “all around us” -> radioactive decay of atomic nuclei(natural) n --> p + e + ne Where are the Neutrinos? every person is a neutrino – emitter: 340 millions per day 20 milligrams radioactive potassium (40K)

  5. -> from nuclear reactors -> from the sun Where are the Neutrinos? • 4x1014 neutrinos per second from the sun • are traversing our body, but ... • ...in 100 years, only 1 solar neutrino interacts • with our body. • One would need an iron block 1016 meters long in order to “stop” 50% of the solar neutrinos

  6. -> at accelerators… (high energy neutrinos) (proton + Nucleus -> pions -> decay) p --> m +nm Where are the Neutrinos? -> from collisions of cosmic rays with nuclei in the atmosphere -> everywhere around us (cosmic ...) ... ...

  7. e m t ne nm nt p,n,p,K... p,n,p,K... p,n,p,K... How do we detect neutrinos ? neutrinos interact VERY rarely with matter - when they do, they often produce a lepton of their “own flavour”: NOTE: a minimum amount of energy is needed (to create the mass of the lepton): me = 0.5 MeV, - mm = 106 MeV - mt = 1770 MeV The higher the neutrino energy, the more likely the interaction !

  8. Neutrino mass ? • Standard model of particle physics: n masses “ZERO” • “Direct” mass measurements -> upper limits( in decay experiments measuring kinetic energy of “the partner” )mne < 2.2 eVmnm < 170 keVmnt < 15.5 MeV • What’s the problem ? • OBSERVATION 1 : SOLAR NEUTRINO “DEFICIT”only about 50% of the ne expected are actually observed:ne disappear “en route” from the sun to the earth …

  9. OBSERVATION 2 : “ATMOSPHERIC NEUTRINO ANOMALY” much lessnm“from below” observed w.r.t. expectations nmdisappear “en route” over 10’000 km … ?

  10. Neutrino Oscillation ne Gran Sasso nm nt n’schange flavor !Is this possible? --> Yes, “if neutrinos have mass”!

  11. In Dec. 1999, CERN council approved the CNGS project:  build an intense nm beam at CERN-SPS  search for ntappearance at Gran Sasso laboratory (730 km from CERN) “long base-line”nm--ntoscillation experiment note: K2K (Japan) completed; NuMI/MINOS (US) running

  12. ORGANISATION of CNGS INFN CERN Convention bilateral co-ordination committee CERN and LNGS scientific committees operates the Gran Sasso underground Laboratory, which houses detectors builds and operates CNGS neutrino beam special contributions finance a large fraction of CNGS International Collaborations

  13. The Gran Sasso Laboratory (LNGS)

  14. 730 km might seem too short - but look at the details : Background low enough, event rate still acceptable --> 730 km almost perfect AND, VERY IMPORTANT: - existing laboratory with its infrastructure (since 1987) - large halls directed to CERN - caverns in the GS mountains: 1500 m of rock shielding - tradition in very successful neutrino physics experiments (solar n’s)

  15. p,e,m ne nm t nt nt p,n,p,K... Detecting ntat Gran Sasso -> look for thetlepton: extremely difficult - ttravels less than 1 mm before decaying -> two approaches: (a) very good position resolution (see the decay “kink”) -> OPERA (b) very good energy and angle resolution -> ICARUS

  16. t nt t Neutrinos t decay “kink” A tau event can be identified because it leaves several tracks starting at the same « point » (the neutrino interaction vertex) – one of the tracks (the tau) shows a kink after about ~1 mm. Electron (or muon) ~ 0.6 mm Hadrons 1 mm A detector with excellent spatial resolution is required !

  17. 8.3kg 1 mm t n Pb Couche de gélatine photographique 40 mm assembled in small units called bricks  modular detector  rapid analysis massive « target » : lead plates micrometric precision : emulsions 56 lead plates (1 mm thick) alternating with 56 photographic films (emulsions). Brique Brick 10.2 x 12.7 x 7.5 cm

  18. OPERA: 1800 tons of “detector mass” walls made of bricks (total more than 200’000) -> bricks made of “sandwiches” -> sandwiches made of lead and nuclear emulsion (type of film) artists view (2001)

  19. artists view (2004)

  20. OPERA status, November 2005 SM1 SM2 Target SM1 Aimants

  21. “back to CERN”... CNGS beam-line: the main components (1) (based on CERN experience: PS / SPS neutrino beams -> WANF) p + C (interactions) p+, K+ (decay in flight) m+ + nm

  22. CNGS: the main components (2) 700 m 100 m 1000m 67 m vacuum p + C (interactions) p+, K+ (decay in flight) m+ + nm

  23. CNGS schedule

  24. CNGS works  ground breaking ceremony: 12 October 2000

  25. CNGS civil engineering more than 3 km of tunnels and caverns (diameter 3.1 m -> 6.0 m) more than 45’000 m3 rock to be removed more than 12’000 m3 concrete to be “sprayed” or poured

  26. CNGS -- proton beam -> protons from SPS, 400 GeV -> NEW fast extraction - tested in 2004 -> this extraction system needed for TI8 -> LHC transfer line (but modified for CNGS) -> CNGS p-beam branches off after  100 metres -> 700 metres of proton beam line to CNGS target (proton beam spot: s = 0.5 mm)

  27. CNGS -- proton beam 73 deflection (dipole) magnets(6.4 m long, 11 tons)+ 21 quadrupole magnets + correction dipoles + ... typical “half cell” BEAM corrector Dipole Electrical distribution box 5.6% slope BEAM Quadrupole Magnet Interlock electronics Beam position monitor control electronics

  28. Proton beam tunnel – February 2002

  29. Proton beam tunnel – April 2003

  30. Proton beam tunnel – Dec. 2004

  31. Proton beam tunnel – Feb. 2005

  32. Proton beam tunnel – 1 July 2005

  33. Proton beam tunnel – 13 July 2005

  34. Proton beam – November 2005

  35. beam position ion pump beam profile Proton beam: Monitoring equipment and vacuum system

  36. Proton beam: Final focusing towards the target

  37. Proton beam: last beam position / beam profile monitors upstream of the target station collimator and shielding

  38. CNGS -- target -> 10 cm long graphite rods, Ø=5mm and/or 4mm proton beam Note: - target rods thin / interspaced to “let the pions out” - target rods need to be precisely aligned (0.1 mm) - target needs to be cooled (particle energy deposition)

  39. target unit (assembly of Alu container)

  40. target magazine (4 spare target units)

  41. Target station installed in final configuration – 8 March 2006

  42. target magazine with motors, in the lab

  43. target station motor / indexing finger

  44. CNGS -- focusing devices length: 6.5 m diameter: 70 cm weight: 1500 kg Pulsed devices: 150kA / 180 kA, 7 ms water-cooled: distributed nozzles

  45. “Magnetic Horn” (S. van der Meer, CERN 1961)

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