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H A R P A Hadron Production Experiment at the Proton Synchrotron at CERN. Motivation for the HARP experiment The HARP Detector MiniBooNE and HARP. HARP Motivation (general). Measure absolute inclusive cross-sections for Hadron production with a range of
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H A R PA Hadron Production Experiment at the Proton Synchrotron at CERN • Motivation for the HARP experiment • The HARP Detector • MiniBooNE and HARP
HARP Motivation (general) Measure absolute inclusive cross-sections for Hadron production with a range of targets and primary proton energies.
HARP Motivation (specific) • Neutrino Factory Design • Atmospheric Neutrino Flux Calculations • Neutrino Fluxes for MiniBooNE and K2K • Input to Monte Carlo simulation packages
Neutrino Factory Need to Know: 1. production rates for varying target materials, target size and proton beam energies (2-24GeV). 2. The PT distribution with high precision to optimize muon collection.
Atmospheric Neutrinos Need to Know: 1. Primary Cosmic Ray Flux* 2. Hadron Interaction Model** * known to better than 10% **limited data leads to ~30% uncertainty in atmospheric neutrino fluxes _
MiniBooNE Flux + 8 GeV p Be K+ source of source of e background e+ source of e background K+ e+ source of e background K0L e+
HARP at the CERN PS • 200 meters in diameter • 28 GeV maximum energy • Feeds into SPS • Used to make anti-protons • Used for target expr. - HARP
HARP at the CERN PS East Hall
T9 Secondary Beam at PS • PS protons hit a target producing secondary particles. • Particles are momentum selected allowing HARP to choose beam energy (2 -15 GeV). • However, beam consists of different particles - mainly protons and pions. • TOF measurements distinguish different particles in the beam before hitting the HARP target. NOTE: This is different from MiniBooNE. MiniBooNE gets 8 GeV protons directly from the Booster.
Time Projection Chamber - TPC 10-1 1 10 p(GeV/c)
Resistive Plate Chamber -RPC HV + + + ++ + + + ++ Gas Gas + + + ++ + + + ++ HV
Drift Chambers & Spectrometer Magnet • 0.5 T Vertical Field for momentum spectrometry • Vertical, +5°, -5° wire orientation in drift chambers • 90% Argon, 5% CO2, 5% CH4 gas mixture • 150m - 700m resolution depending on incident angle • Typical single chamber efficiency of 97% + -
Threshold Cerenkov Detector • Filled with C4F10 (perflourobutane) at atmospheric pressure. • Discriminates between protons and pions at high momentum. • At high beam momentum, strange particles (kaons) are also created. C4F10 properties: n = 1.001415 pion threshold = 2.6 GeV/c kaon threshold = 9.3 GeV/c proton threshold = 17.6 GeV/c
TOF Wall, Electron Identifier,Cosmic Trigger Wall,Beam Muon Identifier TOF Wall - plane of scintillator counters to discriminate between protons and pions at low momentum t ~ 210 ps) Electron Identifier - lead-scintillating fiber counters to discriminate between hadrons on the one hand, and photons and electrons on the other. Cosmic Trigger Wall - plane of scintillator sheets to trigger on cosmic muons for monitoring and calibration. Beam muon Identifier - iron-scintillator calorimeter to identify beam muons.
Pion Production and pi/pPID PT vs. PL Box Plot for pion Production (@15GeV) TPC TOF Cerenkov
HARP Targets • Beryllium • Carbon • Aluminum • Copper • Tin • Titanium • Lead } solid targets 2%, 5%, 50%, 100% neutrino factory, MiniBooNE, K2K } • Hydrogen • Deuterium • Nitrogen • Oxygen cryogenic targets atmospheric neutrino flux
MiniBooNE and HARP Production Rates Decay Now Goal ~50% 5% e+ ~50% 5% ~100% 10% K+ e+ K0L ~100% 10% e+
MiniBooNE & HARP • 1.3M events recorded in 2001 for 8 GeV protons on a 2% Be target • In August, 2002, data will be taken for a 5% and a 50% Be target 2% 5% 50% MiniBooNE Target
HARP 2002 Data Taking • Scheduled for 140 days of running in 2002 • 28 days for cryogenic targets • 14 days for special targets • 7 days for setup and calibration • 91 days to run all targets and beam energies • Cross-section measurements at the 1-2% level should be achievable.