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Beam Instrumentation at CNGS. Introduction Layout Beam Instrumentation Summary. P osc * s t cc (arbitrary units). n t ‘Appearance’ Experiment. Beam optimization: Intensity: as high as possible Neutrino energy: matched for n m - n t appearance experiments Product of n m –flux
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Beam Instrumentation at CNGS • Introduction • Layout • Beam Instrumentation • Summary E. Gschwendtner, CERN
Posc*stcc (arbitrary units) nt ‘Appearance’ Experiment • Beam optimization: • Intensity: as high as possible • Neutrino energy: matched for nm-nt appearance experiments • Product of • nm –flux • Oscillation probability nm– nt • Production cross-section nt with matter + Detection efficiency in the experiment E. Gschwendtner, CERN
Beam Parameters Upgrade phase: 3.5 ·1013 p E. Gschwendtner, CERN
700m 100m 1000m 26m 67m vacuum CNGS Layout p + C (interactions)p+, K+ (decay in flight)m+ + nm E. Gschwendtner, CERN
CNGS Schedule ‘today’ E. Gschwendtner, CERN
Target Station E. Gschwendtner, CERN
Horn E. Gschwendtner, CERN
Helium Tubes E. Gschwendtner, CERN
Decay Tube April 2004: vacuum ok E. Gschwendtner, CERN
graphite cooling modules Hadron Stop finished Sept. 2003 E. Gschwendtner, CERN
CNGS Performance For CNGS performance, the main issues are • the geodesic alignment wrt. Gran Sasso Examples: effect on ντ cc events horn off axis by 6mm < 3% reflector off axis by 30mm < 3% proton beam on target < 3% off axis by 1mm CNGS facility misaligned < 3% by 0.5mrad (beam 360m off) • the beam must hit the target very accurately E. Gschwendtner, CERN
2.7m 43.4m 100m 1095m 18m 5m 67m 5m CNGS Secondary Beam Instrumentation TBID/IonCh Muon Detectors IonCh: Ionization Chamber TBID: Target Beam Instrumentation Downstream E. Gschwendtner, CERN
TBID 2 IonCh L/R TBID + 2 Ionization Chambers TBID Monitor ● Secondary emission monitor ● 12 µm Ti foils ● better than 10-4 mbar vacuum Purpose: • Check efficiency with which protons are converted into secondaries • Multiplicity (Compare with BFCT upstream of the target) • Misalignment of the Beam Ionization Chamber ● N2 filled SPS type BLM ● radius = 4.75 cm, bias: 800V-1500V ● 30 gaps, gap-width = 0.55 cm Ionization Chambers as back-up • cross-check with TBID • information on multiplicity and beam-alignment E. Gschwendtner, CERN
Charged particle fluence for misaligned beam 0mm 1mm 2mm Part/cm2/pot 5mm TBID + 2 Ionization Chambers At position of ionization chambers: FLUKA simulations E. Gschwendtner, CERN
Muon Monitors • Monitoring of: • muon intensity • muon beam profile shape • muon beam profile centre • Muon intensity: • Up to 7.7x107 per cm2 and 10.5 µs • Dynamic range: 105 • Accuracies: • absolute 10 % • relative 3 % • reproducibility: cycle to cycle 1%, one year 5% E. Gschwendtner, CERN
µ Muon Monitor Layout • 17 fixed monitors (Ionization Chambers) • Possibility to double number of monitors • 1 movable chamber behind fixed monitors for relative calibration • Movement by stepping motors E. Gschwendtner, CERN
2nd muon pit Beam dump extent µ µ/cm2/1013pot 105 107 part/cm2/1013pot 104 ● target in, magnetic field ▲target in, no magnetic field ○no target 105 Muon Profiles 1st muon pit An updated calculation of neutron fluence in the CNGS first muon pit,A. Ferrari, A. Guglielmi, P.R. Sala FLUKA simulations (P. Sala, not published) E. Gschwendtner, CERN
1stµ-chamber > 20-23GeV 2ndµ-chamber > 30-35GeV Mis-aligned case Aligned case + (1013 pot cm2)-1 + (1013 pot cm2)-1 fastsimulation r (m) r (m) Muon Profiles Example: 6 mm horn neck lateral displacement E. Gschwendtner, CERN
Information Exchange with Gran Sasso • Timing • Expected muon fluence for the nominal CNGS beam intensity (FLUKA) (muons from ν interactions in Gran Sasso rock) • 43.6 µ/m2/1019 pot • 0.98 µ/m2/day or • 196 µ/m2/y • Muon spectrum peaks at low energies: <p> = 16.2GeV/c. E. Gschwendtner, CERN
Cross-Hair + 2 Ionization Chambers Additional Instrumentation Possibilities • Cross-Hair with 2 Ionization Chamber • additional, more accurate information on proton beam • angular accuracy achieved by BPMs (11 m apart) is limited • bigger lever arm (> 100 m) • additional “active” detector is very difficult / expensive • Short Baseline Detector • Rejected (cost, t-appearance) SBL Detector E. Gschwendtner, CERN
Summary • CNGS is on time • First beam in May 2006 • Complete and redundant beam instrumentation • Direction • Intensities E. Gschwendtner, CERN