Luca Stanco – ISTITUTO NAZIONALE di FISICA NUCLEARE - Padova 1 6 Maggio 2010 L’esperimento OPERA e lo studio dei neutrini del fascio CNGS del CERN Gruppo.

Luca Stanco – ISTITUTO NAZIONALE di FISICA NUCLEARE - Padova 1 6 Maggio 2010 L’esperimento OPERA e lo studio dei neutrini del fascio CNGS del CERN Gruppo di Padova: L.Stanco, A.Bertolin, F. Dal Corso, S.Dusini U.Kose, I.Lippi (INFN) R.Brugnera, A.Garfagnini (Università Padova)

Luca Stanco - PadovaOPERA - CTP 2009 2 The experimental challenge of direct detection of TAU’s appearance A touch of physics LongBaseLine experience in Europe (CNGS) “Modern” Nuclear Emulsion Technique (OPERA Detector) RUNS from 2006 to 2009, from DAQ to submicrometric measures: what we have learned, what we are measuring Expectations (in the near future)

Luca Stanco - Padovanu oscillations - BEYOND 2010 3 Luca Stanco - Padova 3 Here is our START and END point: the lepton mixing In 1998 new history for neutrino begins (as a second life) : - Neutrinos oscillate* (SK and afterwords SNO, K2K …): they own masses Why, how, which - Neutrinos mix themselves (CHOOZ and afterwords KamLAND …): MNS matrix * 41 years after Pontecorvo idea on oscillations in 1957

Luca Stanco - Padovanu oscillations - BEYOND 2010 4 Luca Stanco - Padova 4 CHOOZ looked for e →  oscillations (disappearance) PLB 420 (1998) 397 Mainly after KamLAND… re-interpretation of Chooz result in terms of oscillations of Mass eigenstates Gauge eigenstates Mass eigenstates Maki-Nakagawa-Sakata (1962) Lepton mixing arranged (and quark mixing in 1963 by Cabibbo)

Luca Stanco - Padovanu oscillations - BEYOND 2010 5 Luca Stanco - Padova 5 Standard parametrization of Mixing matrix via 3 Euler rotations Message: leptons and quarks mix in a similar way 1) Phase  violates CP and 2) so phases  1,  2 in Majorana picture 3) Matrix unitarity if no sterile neutrino BUT with 3 BIG questions :

Luca Stanco - Padovanu oscillations - BEYOND 2010 6 Luca Stanco - Padova 6 ≈≈≈Oscillations≈≈≈ SK, K2K/Minos, SNO, KamLand YES (they see oscillations) Chooz NO : it did not see anything because S 12 ≈ 0 (L≈ 1 km) and  13 too small “atmospheric” frequency “solar” frequency  m 12 2 =7.5*10 -5 eV 2  m 23 2 =2.5*10 -3 eV 2 Strumia-Vissani, arXiv:hep-ph/0606054v2

Luca Stanco - Padovanu oscillations - BEYOND 2010 7 Luca Stanco - Padova 7 Searching of disappearance:  13 measurements from Reactors suffer from  m 23 correlations Wonderful KamLAND 2008 Results S. Abe et al., Phys. Rev. Lett. 100, 221803(2008)

Luca Stanco – ISTITUTO NAZIONALE di FISICA NUCLEARE - Padova6 Maggio 2010 8 Hamburg 24.10.2005Björn Wonsak L/E is crucial ! sin 2 (2  12 )sin 2 (2  13 ) Example for 3 flavour Oscillation probability !  m 2 13  m 2 12

Luca Stanco - Padovanu oscillations - BEYOND 2010 9 Luca Stanco - Padova 9 e   Log m 2 m1m1 m3m3 m2m2 What is the pattern of neutrino masses?  m 2 23 ~ 2.5 x 10 -3 eV 2  m 2 12 ~ 7 x 10 -5 eV 2 It “probably” looks something like this

Luca Stanco - Padovanu oscillations - BEYOND 2010 10 Luca Stanco - Padova 10 e   Log m 2 m1m1 m3m3 m2m2 But it could look like that m3m3 m2m2 m1m1 What is the pattern of neutrino masses?

Luca Stanco - Padovanu oscillations - BEYOND 2010 11 e   Log m Even more significant is the absolute scale. 10 -2 eV 10 -1 eV 1 eV m1m1 m3m3 m2m2 This? m1m1 m3m3 m2m2 Or that?

U bm stands for QL symmetry or GUT Luca Stanco - Padovanu oscillations - BEYOND 2010 12 Lepton Mixing is weird Masses Mixing What does all that means ? Is there any meaning at all ? (more than those for cabalistes) e.g. Quark-Lepton Complementarity:  l 12 +  q 12 ≈  /4 and  l 23 +  q 23 ≈  /4 U MNS =U bm U + CKM (QLC l ) or U MNS =U + CKM U bm (QLC )

Luca Stanco - Padovanu oscillations - BEYOND 2010 13 However…. What is presently known of MNS matrix: sin 2 2   3 =1.02±0.05 tan 2   2 =0.47±0.6 sin 2 2   3 from fits (or <0.15@  m 2 23 =2.5*10 -3 eV 2, 90% C.L.)  m  3 ) 2 =2.4±0.13*10 -3 eV 2  m  3 ) 2 =7.59±0.21*10 -5 eV 2 e-  triangle Y.Farzan in 0710.4947 (ISS report) Rather poor resolutions still… Look at unitarities of Kobayashi -Maskawa !! (from PDG06) Message: leptons mixing matrix poorly known … and sin  13 =0.15  13 <11.4 0  13 =8.6 0

Luca Stanco – ISTITUTO NAZIONALE di FISICA NUCLEARE - Padova6 Maggio 2010 14 Then what do we have to measure? the BIG items can be studied with LBL experiments Three angles (  12,  13,  23 ) Two mass differences (  m 2 12,  m 2 23 ) The sign of the mass difference  m 2 (±  m 2 23 ) One CP phase (  ) The source of atmospheric oscillations (detect  appearan.)) The absolute mass scale Are neutrino Dirac or Majorana particles (or both)? Are there more - sterile - neutrinos?

Luca Stanco - Padovanu oscillations - BEYOND 2010 15 W.Buchmuller at EPS09: Summary talk Status of the “Standard Models” at this EPS conference: Particles: wealth of data, all consistent with the SM Astrophysics: no phenomena which are inconsistent with conventional physics Cosmology: remarkably precise data, all consistent with cosmological SM Are there hints for new physics, and if yes, at which energy scale? Right-handed neutrinos have been “found”; no exotics have been found Message: be prepared to the unexpected !

Luca Stanco – ISTITUTO NAZIONALE di FISICA NUCLEARE - Padova6 Maggio 2010 16 WHAT IS STILL MISSING IS A DIRECT ABSOLUTE MEASURE OF FLAVOUR CHANGING FROM FLAVOUR A TO FLAVOUR B and in anycase…

Luca Stanco – ISTITUTO NAZIONALE di FISICA NUCLEARE - Padova6 Maggio 2010 17 History of the CNGS* project 1.1979: Prof. A. Zichichi presents his vision to the “Commissione Lavori Pubblici” 2.1992: An internal report describes “CERN Beams for Long Baseline Neutrino Experiments” 3.1997: INFN-CERN Technical Working Group, chaired by K.Huebner, starts preparing the CNGS Technical Design Report 4.1999: December: CERN council approves the CNGS project; a convention is signed between CERN and INFN, “concerning the CNGS facility” 5.2000: October: start of CNGS civil construction 6.2004: June: ceremony to mark the end of CNGS civil construction 7.2005: November: end of installation of equipment, start of hardware commissioning 8.2006: July 10: start CNGS commissioning with beam, first neutrinos at Gran Sasso 9.2006: August 18: CNGS beam handed over to SPS operations team, neutrinos measured in OPERA under nominal flux 10.2007: Very short RUN due a major problem in radiation shielding 11.2008: Good RUN from CNGS: 1.8 * 10 19 p.o.t. (protons on target) 12.2009: Quite good RUN from CNGS: 3.5 * 10 19 13.2010: Very good RUN expected: up to nominal 4.5 * 10 19 p.o.t. *CNGS: Cern Neutrinos’ to Gran Sasso

Luca Stanco – ISTITUTO NAZIONALE di FISICA NUCLEARE - Padova6 Maggio 2010 18 CNGS budget - project budget total: 77.6 MCHF (incl. industrial services, FSU, etc.) of which special contributions cash:54.3 MCHF (Italy, Belgium, Spain, Switzerland) special contributions “in-kind”: 6.8 MCHF (France, Germany) - CERN manpower105 FTE CNGS project completed within the budget and schedule

Luca Stanco – ISTITUTO NAZIONALE di FISICA NUCLEARE - Padova6 Maggio 2010 19 3.5 0

Luca Stanco – ISTITUTO NAZIONALE di FISICA NUCLEARE - Padova6 Maggio 2010 20 Scheme for the production of neutrinos vacuum 800 m 100 m 1000m 67 m p + C  (interactions)   , K , (   )  (decay in flight)      Helium tanks

Luca Stanco – ISTITUTO NAZIONALE di FISICA NUCLEARE - Padova6 Maggio 2010 21

Luca Stanco – ISTITUTO NAZIONALE di FISICA NUCLEARE - Padova6 Maggio 2010 22 Proton beam – end of vertical deflection

CNGS (CERN Neutrino To Gran Sasso) beam 25 17 GeV L730 km L/E43 Km/GeV ( e + e )/  CC 0.87%  /  CC 2.1%  prompt negligible Protons from SPS: 400 GeV/c Cycle length: 6 s 2 extractions separated by 50 ms Pulse length: 10.5  s Beam intensity: 2.4 10 13 proton/extr. Expected performance: 4.5  10 19 pot/year Nominal beam performance (4.5x10 19 pot/y) Target mass of 1.3 kton  Expected number of interactions in 5 years running: ~ 23600  CC+NC ~ 170 e + e CC ~ 115  CC (  m 2 = 2.5 x 10 -3 eV 2 ) 25 Flux optimized to produce the max. number of  CC After efficiencies, 10 tau decays are expected to be observed, with <1 background events

Luca Stanco - PadovaOPERA - CTP 2009 26 CNGS Run 2008: 18 June - 03 Nov 2008 Total: 1.78·10 19 pot 18kV cable repair MD PS magnet exchange, septum bakeout MD SPS timing fault: vacuum leak & magnet exchange CNGS maintenance SPS extraction line: Magnet ground fault MD CNGS maintenance Nominal: 4.5 10 19 pot/yr for 5 years Beam to CNGS, LHC, FT, MD Beam to CNGS, LHC, FT Beam to CNGS, MD

Luca Stanco - PadovaOPERA - CTP 2009 27 CNGS Run 2009: 1 June - end Nov 2009 27 Unix time Pot/extraction 2 E 13 pot/extraction Extraction 1 Extraction 2 Saturday 30/5/09 PS vacuum leak 10/6 00:00 11/6 1:07 MD Monday 15/6 8:00 Friday 19/6 8:00 MD + Septum water leak Tuesday 30/6 8:00 Friday 3/7 7:15 MD 12/7 1:07 16/7 8:00 MD 10/8 0:0 13/8 17:24 MD 31/7 LINAC2 vacuum leak PS magnet short MD 14/9-18/9 MD 22/9-23/9 MD 26/8 PS septum 2/10-11/10 CNGS ventilation 28/9

Luca Stanco - PadovaOPERA - CTP 2009 28 Average efficiency 70.26% Peak efficiency 78% 2009

29 CNGS beam performance 2008 run2009 run total 1.782 E 19 pot 3.522 E 19 pot On-time events1012221428 candidate in the target 16983693 Pot collected during the 2009 CNGS run Foreseen stops Unforeseen stops

Luca Stanco – ISTITUTO NAZIONALE di FISICA NUCLEARE - Padova6 Maggio 2010 30 OPERA O scillation P roject with E mulsion-t R acking A pparatus Dopo il fascio di NEUTRINI… il rivelatore per osservarli ! - 1300 tonnellate di piombo “osservate” con emulsioni fotografiche (  =1  m) e triggerate con rivelatori di scintillazione (  =1 cm) - 2000 tonnellate di ferro “osservate” con rivelatori elettronici (  =1 mm) per complemento della misura Struttura modulare doppia ICARUS: next talk…

Luca Stanco – ISTITUTO NAZIONALE di FISICA NUCLEARE - Padova6 Maggio 2010 31 33 INSTITUTIONS, ~170 PHYSICISTS IPNL, IRES, LAPP INR ITEP JINR, Obninsk Zagreb L’Aquila, Bari, Bologna, Napoli, Padova, Roma, Salerno, LNF, LNGS Bern Neuchatel Zurich Brussels Hamburg, Münster, Rostock Sofia Aichi, Toho Kobe, Nagoya Utsunomiya Technion Haifa METU Ankara IHEP Beijing Shandong Gyeongsang University OPERA is an International Collaboration Circa 60 M€

Luca Stanco – ISTITUTO NAZIONALE di FISICA NUCLEARE - Padova6 Maggio 2010 32 What is the goal of OPERA Once the oscillations established, a large international program has been set for checking all parameters of the flavor transitions: Japan ( KEK to Super-Kamiokande), US ( Fermi Lab to MINOS )  μ disappearance Europe ( CERN to Gran Sasso )  τ appearance  OPERA

Luca Stanco – ISTITUTO NAZIONALE di FISICA NUCLEARE - Padova6 Maggio 2010 33 Detection of the  appearance signal Two conflicting requirements:  Large mass  low Xsection  High granularity  signal selection  background rejection Target:1300 tons, 5 years running 24 000 neutrino interactions ~170  interactions ~10  identified < 1 event of background Toplogy selection:  Kink signature The challenge is to identify  interactions from  interactions   -- Decay “kink”  -- ~1 mm  oscillation --

The OPERA basic unit: the « Brick » Based on the concept of the Emulsion Cloud Chamber : - 57 emulsion films + 56 Pb plates - a box with a removable pair of films (Changeable Sheets) (interface to the electronic detectors)  High space resolution in a large mass detectors with a completely modular scheme Bricks are complete stand-alone detectors:  Measurement of hadrons momenta by multiple scattering 12.5cm 10.2cm  Neutrino interaction vertex and kink topology reconstruction  dE/dx: pion/muon separation at low energy (at end of range)  Electron identification and measurement of the energy of electrons and gammas (electromagnetic calorimetry) Tracks reconstruction accuracy in emulsions:  x  0.3 µ m   2 mrad 37 beam brick CS Emulsion film Lead plates Emulsion film

Luca Stanco – ISTITUTO NAZIONALE di FISICA NUCLEARE - Padova6 Maggio 2010 39 What the microscope CCD sees in one film... 170  m 250  m

Luca Stanco – ISTITUTO NAZIONALE di FISICA NUCLEARE - Padova6 Maggio 2010 40 Structure of the OPERA Experiment 29 target planes / supermodule (in total: 155,000 bricks, 1350 tons)  Targets Magnetic Spectrometers Proposal: July 2000, installation at LNGS started in May 2003 First observation of CNGS beam neutrinos : August 18 th, 2006 SM1SM2

Luca Stanco – ISTITUTO NAZIONALE di FISICA NUCLEARE - Padova6 Maggio 2010 41 Veto plane (RPC) High precision tracker Instrumented dipole magnet ● 6 4-fold layers of ● 1.53 T drift tubes ● 22 XY planes of RPC in both arms Muon spectrometer (8×10 m 2 ) SM1 SM2 0.68 kton Target and Target Tracker (6.7m) 2 ● Target : 77500 bricks, 29 walls ● Target tracker : 31 XY doublets of 256 scintillator strips + WLS fibres + multi-anodes PMT for Brick selection Muon tracks reconstruction The OPERA detector

Luca Stanco - PadovaOPERA - CTP 2009 42 The completion of the OPERA construction (*) OPERA is based on the only proven technology (DONUT) to identify  on an event-by-event basis (nucl.emuls.&lead driven by real time detectors). It is celebrated as a major engineering achievement since it brought such technology to an immense size (1.25 kton) (*) R.Acquafredda et al., “The Opera experiment in the CERN to GS beam”; JINST, 4:P04018,2009 10 19 sensitive points of measurement ! 1% to be spanned through… of which 1% to be recorded…

OPERA as real time experiment  CNGS events are selected on a delayed time coincidence between proton extractions from SPS and the events in OPERA.  The synchronization is based on GPS with precision of ~100 ns (can be improved to 10ns)  DAQ livetime during CNGS is 98.8%  Real time detection of neutrino interaction in target and in the rock surrounding OPERA 45 beam angle T OPERA T SPS GPS Time distribution of events in the neutrino run. Event time difference wrt the closest extraction Angular distribution of muons produced by  interactions in the rock

CNGS Beam TT 1st super-module2nd super-module bricks scintillator Target areaMuon spectrometer 1. Event Triggering – Location – ECC Extraction Brick Wall and Brick Manipulation system. 49

ECC 10cm 2.6cm 12.5cm Changeable Sheet (CS) T TT T 2. The emulsion interface films (CS), are separated from the brick and scanned looking for a connection with respect to the electronic detectors predictions 50 Angular accuracy of the electronic predictions (muons) Position accuracy of the electronic Predictions (muons)  high signal/noise ratio for event trigger and interface between millimetric world of ED and micrometric world of the bricks for scanning time reduction

3. If tracks are found in the CS, the brick is exposed to X-rays beam and to cosmic rays for sheets alignment. 4. The brick is disassembled and the emulsion films are developed and sent to one of scanning labs European Scanning SystemSuper-UltraTrackSelector CMOS camera Scanning speed 20 cm 2 /h EUROPE : Brick emulsion scanning: 9 labs LNGS is CS scanning center High speed CCD camera (3 kHz) Scanning speed up to 75 cm 2 /h JAPAN: Brick emulsion scanning: 2 labs Nagoya is CS scanning center 51

 12 57 565554 53 5251504948 … 2 1 CS prediction Scan-Back start from CS prediction Volume Scan 5 up-stream 10 down-stream Tracks found in CS are followed in the most downstream films of the brick up to their stopping point : Scan-back procedure Volume scan: a zone of ~ 2 cm 2 in several films is measured around track disappearance point(s) to confirm the presence of the interaction 52 5. Brick Scanning and neutrino interaction vertex location 6. Vertex tracks may be followed in the forth direction for kinematical measurements Data are published on the central DataBase O(GB/event)

NC/CC ratio measurement after removal of external bck accumulation at target borders: Data 2008: NC/CC= 0.230 ± 0.014 (stat.) Data 2009: NC/CC= 0.230 ± 0.009 (stat.) MC: NC/CC= 0.236 ± 0.005 (stat.) 53 Muon reconstruction and hadronic showers behaviour in reasonable agreement data/MC for  CC events Raw hadronic energy deposited in TT scintillator (MeV) Shower transverse profile  CC events : quantities measured in the ED Muon momentum Track length x density (range for muon id) Muon identification: Range cut Range vs momentum measured in bricks with MCS Best brick-ED angular matching

54 Reconstructed tracks and momenta in bricks MCS measurement of soft muons (p<6 GeV) in order to validate the technique for kinematical measurements and compare to momentum from ED Track slope (rad)  Data  Monte Carlo   = (22±4)% Soft muons measured in OPERA Momentum from electronic detector (GeV/c) Momentum from MCS (GeV/c) Event track multiplicity distribution  p p <>=2.8 Pmcs-Pspectro Pspectro Reconstructed tracks at the primary vertex for  CC events Muon slopes measured at primary vertex compared to MC (at generator level !)

Scanning activities (till fall 2009) were focused on vertex location 55 Decay search  A systematic DECAY SEARCH was started on 2008 and 2009 data in order to find all possible decay topologies 1) improvement of the vertex definition and IP distribution 2) detection of possible kink topologies (on tracks attached to primary vertex) 3) search for extra tracks from decays not attached to primary vertex 20 charm candidates were found so far (in good part with the scan-back and vertex location procedures). Charm events are the control sample for decay search  completion of systematic decay search for final evaluation Impact parameter distribution Data IP  m Muon I.P.    (MC)

56 Events location summary for 2008 run Events location summary for 2009 run About 1400 neutrino interaction vertices localized

57 Topological identification and kinematical confirmation of a charm event Primary vertex Decay vertex All units are in microns ! A D 0 4 prongs decay candidate :

58 Electrons and photons reconstruction: primary vertex electromagnetic shower A e CC interaction candidate : E ~0.5 GeV E ~8.1 GeV 2 e-showers give a reconstructed mass 160 ±30 MeV/c 2   e-pair e+ e-  A  CC interaction with  0 production : 70% of 1-prong hadronic  decays include one or more  0. Important to detect gamma from tau decay to improve S/N. Gamma detection detection of shower detection e-pair at start point

Luca Stanco – ISTITUTO NAZIONALE di FISICA NUCLEARE - Padova6 Maggio 2010 60 1. Significanza dell’osservazione del TAU in OPERA Domande a cui deve rispondere OPERA: 1. Esiste l’oscillazione nu(mu)-nu(tau) ? 2. Quanti sono i tau “oscillati” ? calcoliamola in funzione degli EVENTI osservati (invece che la canonica funzione di LUMINOSITA’)

Luca Stanco - PadovaOPERA - CTP 2009 61 Conclusions OPERA goals: 1) tau’s evidence (~ 2 events expected to be observed u.t.n.) 2) tau’s oscillation confirmation 3) Ancillary results on charm and cosmics 4) Confirm the unexpected ! OPERA challenges: 1) from cm to micron precisions 2) Intimate interplay of “standard” and “subtleties” technologies 3) “Industrial” activities not only at construction time but even heavier at analysis stage 4) Up till now we collected 5.3 x 10 19 p.o.t. OPERA represent a unique measurement to stay in future textbooks (~25 taus produced)

Luca Stanco – ISTITUTO NAZIONALE di FISICA NUCLEARE - Padova6 Maggio 2010 62 Backup Slides

Luca Stanco – ISTITUTO NAZIONALE di FISICA NUCLEARE - Padova6 Maggio 2010 63 Evento sotto analisi al laboratorio di scanning di LEGNARO

Luca Stanco – ISTITUTO NAZIONALE di FISICA NUCLEARE - Padova6 Maggio 2010 65 Neutrino interaction: 5 hadrons, 1 muon, 2 photons (one converts)

Luca Stanco – ISTITUTO NAZIONALE di FISICA NUCLEARE - Padova6 Maggio 2010 66 Electron reconstruction and identification Reconstruction principle: “backpropagation” method to collect basetracks in a cone using connection criteria (slopes and positions) e/  separation: Method use a neural network based on the reconstructed shower longitudinal profile and the number of collected basetracks 6 GeV electron (real data) in 20 emulsions ~3.3 X 0

Luca Stanco – ISTITUTO NAZIONALE di FISICA NUCLEARE - Padova6 Maggio 2010 67 The CNGS UTC* systems and the measurement of neutrino velocity *UTC: Universal Time Coordinate

Luca Stanco – ISTITUTO NAZIONALE di FISICA NUCLEARE - Padova6 Maggio 2010 68 The Global Positioning System (GPS) The GPS system was built and it is controlled by the US militaries (DOD), it is composed by at least 24 satellites orbiting at 20000 Km, the budget for maintenance is 500 M$/year Depending on the place and the time of the day on average between 5 and 8 satellites are visible by an observer on the earth

Luca Stanco – ISTITUTO NAZIONALE di FISICA NUCLEARE - Padova6 Maggio 2010 69 Each satellite is equipped with a Cs atomic clock and transmits its time and position (computed with its ephemeris): e.g.: x1,y1,z1,t1 The observer on the earth, getting the quadrivectors of 4 satellites has to solve a system of 4 equations in order to find his own time and position: x0,y0,z0,t0 (x0-x1) 2 + (y0-y1) 2 + (z0-z1) 2 = c 2 (t0- t1) 2 (x0-x2) 2 + (y0-y2) 2 + (z0-z2) 2 = c 2 (t0- t2) 2 (x0-x3) 2 + (y0-y3) 2 + (z0-z3) 2 = c 2 (t0- t3) 2 (x0-x4) 2 + (y0-y4) 2 + (z0-z4) 2 = c 2 (t0- t4) 2 Then x0,y0,z0,t0 can be converted in the more familiar Latitude,Longitude,Altitude and time

Luca Stanco – ISTITUTO NAZIONALE di FISICA NUCLEARE - Padova6 Maggio 2010 70 o At least 4 satellites are needed, if only 3 satellites are visible one can still compute the position by imposing the constraint of being on the surface of the earth (geoid model), in this case the altitude cannot be measured. In case n (n>4) satellites are visible the system becomes overconstrained and the precision improves as 1/sqrt(n) o If the observer knows already his position x0,y0,z0 (fixed observer) then just one satellite is needed in order to measure t0 (time mode) o One assumes the speed of the ligth in vacuum (c) but this is not exactely the case since the ionosphere is a medium: The satellite emits on two frequencies: L1=1.575 GHz (C/A code) L2=1.2276 GHz (P(y) code) in order to model and correct for the real speed of the ligth in the ionosphere (differential GPS)

Luca Stanco – ISTITUTO NAZIONALE di FISICA NUCLEARE - Padova6 Maggio 2010 71 The satellites needs to know their ephemeris and the atomic clocks need continously to be readjusted from the ground stations with a complex procedure. Main control at Colorado Springs. Relativistic corrections are not negligible and are correctly taken into account

Luca Stanco – ISTITUTO NAZIONALE di FISICA NUCLEARE - Padova6 Maggio 2010 72 CERN-LNGS UTC clocks intercalibration For the neutrino spill syncronization both CERN and LNGS have a double unit (including a spare) UTC clock system, but from different manifacturers. The CERN system was calibrated by the Swiss metrology institute METAS. CERN and LNGS systems have comparable performance (<100 ns) and their single units are in both cases based on a GPS system + Rb clock. One of the CERN UTC units was installed and running for one month in Gran Sasso in order to check for relative offsets and time stability of the two systems. Action was taken also to measure all the delays in the LNGS time distribution chain LNGS UTC cloks (ESAT) CERN Symmetricom XL-DC unit installed at LNGS

Luca Stanco – ISTITUTO NAZIONALE di FISICA NUCLEARE - Padova 1 6 Maggio 2010 L’esperimento OPERA e lo studio dei neutrini del fascio CNGS del CERN Gruppo.

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Luca Stanco – ISTITUTO NAZIONALE di FISICA NUCLEARE - Padova 1 6 Maggio 2010 L’esperimento OPERA e lo studio dei neutrini del fascio CNGS del CERN Gruppo.

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Presentation on theme: "Luca Stanco – ISTITUTO NAZIONALE di FISICA NUCLEARE - Padova 1 6 Maggio 2010 L’esperimento OPERA e lo studio dei neutrini del fascio CNGS del CERN Gruppo."— Presentation transcript:

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