ISS, 23 September 2005E. Gschwendtner, CERN1 Beam Instrumentation at CNGS 1. Introduction 2. Layout 3. Beam Instrumentation 4. Summary

ISS, 23 September 2005E. Gschwendtner, CERN2  ‘Appearance’ Experiment P osc *   cc (arbitrary units) Beam optimization:  Intensity: as high as possible  Neutrino energy: matched for  -  appearance experiments Product of   –flux 2. Oscillation probability  –   3. Production cross-section  with matter + Detection efficiency in the experiment

ISS, 23 September 2005E. Gschwendtner, CERN3 Beam Parameters Upgrade phase: 3.5 · p

ISS, 23 September 2005E. Gschwendtner, CERN4

ISS, 23 September 2005E. Gschwendtner, CERN5 CNGS Layout p + C  (interactions)   , K   (decay in flight)      vacuum 700m100m1000m67m26m

ISS, 23 September 2005E. Gschwendtner, CERN6 ‘today’ CNGS Schedule

ISS, 23 September 2005E. Gschwendtner, CERN7 Target Station

ISS, 23 September 2005E. Gschwendtner, CERN8 Horn

ISS, 23 September 2005E. Gschwendtner, CERN9 Helium Tubes

ISS, 23 September 2005E. Gschwendtner, CERN10 Decay Tube April 2004: vacuum ok

ISS, 23 September 2005E. Gschwendtner, CERN11 graphite cooling modules Hadron Stop finished Sept. 2003

ISS, 23 September 2005E. Gschwendtner, CERN12 CNGS Performance For CNGS performance, the main issues are  the geodesic alignment wrt. Gran Sasso Examples:effect on ν τ 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

ISS, 23 September 2005E. Gschwendtner, CERN m 100m 1095m18m5m 67m 2.7m CNGS Secondary Beam Instrumentation TBID/IonChMuon Detectors TBID: Target Beam Instrumentation Downstream IonCh: Ionization Chamber

ISS, 23 September 2005E. Gschwendtner, CERN14 TBID + 2 Ionization Chambers TBID 2 IonCh L/R Purpose:  Check efficiency with which protons are converted into secondaries → Multiplicity (Compare with BFCT upstream of the target) → Misalignment of the Beam TBID Monitor ● Secondary emission monitor ● 12 µm Ti foils ● better than mbar vacuum  Ionization Chambers as back-up  cross-check with TBID  information on multiplicity and beam-alignment Ionization Chamber ● N 2 filled SPS type BLM ● radius = 4.75 cm, bias: 800V-1500V ● 30 gaps, gap-width = 0.55 cm

ISS, 23 September 2005E. Gschwendtner, CERN15 TBID + 2 Ionization Chambers FLUKA simulations Charged particle fluence for misaligned beam 1mm 0mm 2mm 5mm Part/cm 2 /pot At position of ionization chambers:

ISS, 23 September 2005E. Gschwendtner, CERN16 Muon Monitors Monitoring of:  muon intensity  muon beam profile shape  muon beam profile centre Muon intensity:  Up to 7.7x10 7 per cm 2 and 10.5 µs Dynamic range: 10 5 Accuracies:  absolute 10 %  relative 3 %  reproducibility: cycle to cycle 1%, one year 5%

ISS, 23 September 2005E. Gschwendtner, CERN17 Muon Monitor Layout µ  17 fixed monitors (Ionization Chambers) Possibility to double number of monitors  1 movable chamber behind fixed monitors for relative calibration  Movement by stepping motors

ISS, 23 September 2005E. Gschwendtner, CERN18 Muon Profiles part/cm 2 /10 13 pot µ Beam dump extent 1 st muon pit An updated calculation of neutron fluence in the CNGS first muon pit, A. Ferrari, A. Guglielmi, P.R. Sala µ/cm 2 /10 13 pot ● target in, magnetic field ▲ target in, no magnetic field ○ no target 2 nd muon pit FLUKA simulations (P. Sala, not published)

ISS, 23 September 2005E. Gschwendtner, CERN19 Muon Profiles 1 st µ-chamber > 20-23GeV  + (10 13 pot cm 2 ) -1 r (m) Mis-aligned case Aligned case 2 nd µ-chamber > 30-35GeV fast simulation Example: 6 mm horn neck lateral displacement

ISS, 23 September 2005E. Gschwendtner, CERN20 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/m 2 /10 19 pot  0.98 µ/m 2 /day or  196 µ/m 2 /y  Muon spectrum peaks at low energies: = 16.2GeV/c.

ISS, 23 September 2005E. Gschwendtner, CERN21 Additional Instrumentation Possibilities Short Baseline Detector Cross-Hair + 2 Ionization Chambers  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  Rejected (cost,  -appearance) Cross-Hair with 2 Ionization Chamber SBL Detector

ISS, 23 September 2005E. Gschwendtner, CERN22 Summary CNGS is on time  First beam in May 2006 Complete and redundant beam instrumentation  Direction  Intensities