June 2001HARP Status – Chris Booth1 Status of the HARP Experiment Chris Booth University of Sheffield

June 2001HARP Status – Chris Booth2 Outline Motivation –Neutrino Physics –Muon storage ring design Requirements and Design –Acceptance –Particle identification History and Status –Results from the technical run –Current status

June 2001HARP Status – Chris Booth3 Motivation – Neutrino Physics! Conventional accelerator beams p N   + X   +   e + e  K + X   + e + e Neutrino physics – first indication of physics beyond S.M. Solar neutrinos Atmospheric neutrinos Neutrino beams (LSND, ….) Mixture of species , , e Range of momenta of progenitors Uncertain fluxes

June 2001HARP Status – Chris Booth4 Motivation – reduced systematics Aims of HARP Optimal design of target and collector for source Calculation of atmospheric fluxes Calibration of beams for K2K and MiniBooNe Stopped  source for solid state physics E.g. Atmospheric neutrinos: 30% uncertainty in fluxes 7% uncertainty in ratio  / e  Dedicated neutrino beams, from monoenergetic muons.

June 2001HARP Status – Chris Booth5 Targetry for Neutrino Factory Proposal to build a muon storage ring for a -factory. – (also first stage of a high energy  -collider) High -fluxes are required for precision measurements –~10 12 m –2 yr –1 for 732 km baseline or ~10 10 m –2 yr –1 for 7332 km –Requires ~10 21 muons per year –Requires ~10 21 pions per year –This assumes capturing ~0.6 pions/incident proton Need high Z target  + /  – ratio should be ~1 requires low A Several proton driver designs CERN: Linac+accumulator p=2 GeV/c FNAL: Synchrotron p=16 GeV/c CERN-BNL:Synchrotron p=24 GeV/c

June 2001HARP Status – Chris Booth6 HARP: hadronic d  /dP T /dP L at various beam energy and targets

June 2001HARP Status – Chris Booth7 Targets and pion capture Two parameters are important: p Tmax determined by inner radius of the capture solenoid Acceptance of the RF-system given by p L spectrum of pions  To optimise the target and capture system requires good knowledge of the p T and p L spectra to very low p T values.

June 2001HARP Status – Chris Booth8 Low Energy pion production Observe pions and protons

June 2001HARP Status – Chris Booth9 Surely it has all been done before ! Lack of data!! few old experiments: Allaby et al.(1970) Eichten et al.(1972) 24 GeV p Be small acceptances in many cases only Be target with beam energies in the range GeV Xlab =p  /p beam

June 2001HARP Status – Chris Booth10 Data required for a -Factory We can optimize the neutrino factory design by: 1. maximizing the  +  – production rate /proton /GeV 2. knowing with high precision (<5%) the P T distribution BUT the current simulation packages (FLUKA and MARS) show a 30%-100% discrepancies on pion yields

June 2001HARP Status – Chris Booth11 Università degli Studi e Sezione INFN, Bari, Italy Institut für Physik, Universität Dortmund, Germany Joint Institute for Nuclear Research, JINR Dubna, Russia Università degli Studi e Sezione INFN, Ferrara, Italy CERN, Geneva, Switzerland Section de Physique, Université de Genève, Switzerland Laboratori Nazionali di Legnaro dell' INFN, Legnaro, Italy Institut de Physique Nucléaire, UCL, Louvain-la-Neuve, Belgium Università degli Studi e Sezione INFN, Milano, Italy Institute for Nuclear Research, Moscow, Russia Università "Federico II" e Sezione INFN, Napoli, Italy Nuclear and Astrophysics Laboratory, University of Oxford, UK Università degli Studi e Sezione INFN, Padova, Italy LPNHE, Université de Paris VI et VII, Paris, France Institute for High Energy Physics, Protvino, Russia Università "La Sapienza" e Sezione INFN Roma I, Roma, Italy Università degli Studi e Sezione INFN Roma III, Roma, Italy Rutherford Appleton Laboratory, Chilton, Didcot, UK Dept. of Physics and Astronomy, University of Sheffield, UK Faculty of Physics, St Kliment Ohridski University, Sofia, Bulgaria Università di Trieste e Sezione INFN, Trieste, Italy Univ. de Valencia, Spain HARP experiment PS institutes 107 authors

June 2001HARP Status – Chris Booth12 Hadronic production cross sections (d  /dP T,dP L ) at various energies and with various targets Goal: 2% accuracy over all phase space O(10 6 ) events/setting, low systematic error CERN PS, T9 beam, 2 GeV/c – 15 GeV/c Approval: December 1999 "Stage 0" Technical run with partial set-up, 25 September – 25 October 2000 Stage 1 Measurements with solid and cryogenic targets, early 2002 Future plans: Measurements with incoming Deuterium and Helium, 2002 ~100 GeV incoming beam, using NA49 set-up HARP will measure......

June 2001HARP Status – Chris Booth13 Recycling! Very short timescale  re-use existing equipment & designs DC & TOF wall from NOMAD prototype TPC from ALEPH dipole magnet from Orsay Electron-identifier from CHORUS … However, in practice many changes, re-optimisations etc required, so most has had to be rebuilt!

June 2001HARP Status – Chris Booth14 Deliverables Input data for the design of the Neutrino factory/Muon collider Input data for the Atmospheric neutrino flux calculations Precise predictions of the neutrino fluxes for the K2K and MiniBooNE experiments targets will be installed in HARP Input data for the hadron generators in Monte Carlo simulation packages GEANT-4

June 2001HARP Status – Chris Booth15 Parameters to optimise: proton energy, target material and target geometry, D 2 Proton beam 2-24 GeV CERN: Linac 2 GeV BNL: Synch. 24 GeV FNAL: Synch. 16 GeV Various high-Z Targets Li,Be,C,Al,Cu,liq.Hg etc. (thin and thick)  + /  - ratio: D 2 beam backward-going pions stopped muon source We Need new DATA

June 2001HARP Status – Chris Booth16 Large acceptance (even backward) p/  separation K/p separation electron/p separation Momentum evaluation over 2 decades (100 MeV–10 GeV) Acceptance and particle-ID

June 2001HARP Status – Chris Booth17 Acceptance and particle-ID Acceptance Target inside TPC Forward spectrometer (drift chambers) Identification Time of flight (RPCs & scintillators) dE/dx (TPC) Cherenkov e &  identifiers (scintillator/absorbers)

June 2001HARP Status – Chris Booth18 Experimental setup drift chambers Cherenkov TOF wall electron identifier spectrometer magnet TPC solenoid magnet forward trigger forward RPC muon identifier beam …-id at large p L Tracking, low p T spectrometer particle-id at low p L, low p T High p T and particle-id

June 2001HARP Status – Chris Booth19 Targets – U.K. responsibility Cryogenic targets all 6 cm long target tube target holder targetZ thin l (cm) thick l (cm) Be40.81 C Al Cu Sn Ta Pb H2H2 D2D2 N2N2 O2O2 K2K target~60 cm Al MiniBooNE target~65 cm Be Solid targets Special targets > 99.99% pure

June 2001HARP Status – Chris Booth20 Experimental setup beam TPC field cage TPC pad plane/readout target ITC inner trigger cylinder solenoid coil RPC barrel 2.24 m

June 2001HARP Status – Chris Booth21 TPC beam 1.59 m PAD plane readout HV plane ~ 22 kV “cork” (HV degrading + calibration systems) Field cages HARP Stesalit wall (8 mm outer, 2 mm inner) metallisation

June 2001HARP Status – Chris Booth22 TPC Gate Wiring scheme PAD size 6.5  15 mm 2 20 PAD rows 3972 PADs in total "CALICE" preamplifier chips on the back of the PAD plane  flex connection  buffer amplifier  pico-coax cable (5 m)  FEDC (VME card with 10-bit ADC and digital circuit for data reduction) Wire planes: anode wires (no field wires) cathode wires gating grid all wiring around precision pins on a 7 mm wide spoke-wheel gate wiring 32 cm

June 2001HARP Status – Chris Booth23 TPC TPC calibration systems: Mn source Photo-emission from UV light (aluminised optical fibre) Gate pulsing Radioactive gas Cosmics Gas choice: 90% Ar, 10% CO 2 Gas speed: 5 cm/  s Total drift time: 32  s  320 time samples at 10 MHz Expect around 1% of the 1.3  10 6 PAD-time words to contain a hit  data reduction in the FEDC  up to ~50 kBytes per event to be read out for up to 1000 events/spill

June 2001HARP Status – Chris Booth24 TPC The TPC design takes into account the results of many detailed simulations/calculations on: gas choice, B-field dependence, ion movements, gating studies, simulation of PAD response function, electrostatics for wire planes and field cage, mechanical deformations Charge sharing With field wires Charge sharing Without field wires

June 2001HARP Status – Chris Booth25 TPC TPCino prototype mini-TPC with 24 PADs final wire configuration 90% Ar, 10% CO 2 Short drift ~5 cm "Calice" preamps Buffer amplifiers Pico-coax cable Alice FE Digital Card DATE DAQ Monitoring Laser for photo emission Allows to test PAD signals under various conditions Gating system Calibration systems PAD response function dE/dx resolution TPCino Pad Response Function measured with (point-like)  -source and oscilloscope readout TPCino Pad Response Function measured with (point-like)  -source and oscilloscope readout

June 2001HARP Status – Chris Booth26 TPC HARP-TPCino Full electronic chain Point-like photo emission source preliminary:  pulseheight 10-14% HARP-TPCino Full electronic chain Point-like photo emission source preliminary:  pulseheight 10-14%

June 2001HARP Status – Chris Booth27 TPC TPCino test setup, full readout chain, online monitoring FWHM of signal duration 200 ns scope view of a single PAD 10 MHz readout 30  s

June 2001HARP Status – Chris Booth28 RPC Additional detector (not in the proposal) Particle (e –  ) separation at low momenta (150 MeV – 250 MeV) <200 ps time resolution needed can be achieved with RPC 4 gaps of 0.3 mm thickness module size:192 cm  10.6 cm PAD size:10.4 cm  2.95 cm Barrel-part, around the TPC:30 RPC modules Forward part, at the TPC exit:16 RPC modules Each PAD is read out by its own (OPA687) preamplifier 8 PADs are added together after the amplifier stage Signal split into: trigger, TDC, ADC Total 368 readout channels

June 2001HARP Status – Chris Booth29 RPC Prototype results (T10 test beam)  = 104 ps Time (TDC channel 50 ps) (30 ps trigger resolution still folded in)

June 2001HARP Status – Chris Booth30 Solenoid magnet Gap radius45 cm Gap length224 cm Number of coils88 Field strength0.7 T DC current910 A Power consumption0.72 MW Ex-ALEPH TPC90 magnet Magnet Requirements: Homogeneous field in TPC (1.6 m long) B r /B z < 1% Field strength 0.7 T Downstream return yoke removed Needed 50 cm extra length  20 new coils  of which 14 with a larger radius new coils

June 2001HARP Status – Chris Booth31 Spectrometer magnet Gap height88 cm Gap width241 cm Gap depth171 cm Field strength (vertical) 0.5 T  BdL 0.68 Tm Current2910 A Power consumption0.36 W August 2000  BdL 0.68 Tm 1 m

June 2001HARP Status – Chris Booth32 Spectrometer magnet B y (in y,z plane) B y (in x,z plane) interpolation of magnetic field measurements

June 2001HARP Status – Chris Booth33 Drift chambers 23 chambers installed in HARP (69 planes) Drift Chambers 32 mm drift length 1 chamber = 1 triplet 1 module = 4 chambers wires at –5º, 0º, +5º total 126 wires/chamber 8 mm gas gap gas: 90% Ar, 9% CO 2, 1% CH 4 Read out by: CAEN TDC V767

June 2001HARP Status – Chris Booth34 Cherenkov beam 5.4 m 2 rows of 19 PM's (8") in magnetic shielding additional focusing: Winston cones Cherenkov box, 30 m 3 filled with C 4 F 10 gas cylindrical mirror, 8 m 2 curvature radius 2.4 m  2.6 GeV/c K9.3 GeV/c p17.6 GeV/c threshold

June 2001HARP Status – Chris Booth35 C 4 F 10 threshold mode 34 Chooz PMs EMI 9356KA Optimisation of granularity for expected occupancy PM shielding requirements Mirrors/focussing design scheme (and technology)  Serious construction problems! Cherenkov Design Serious leaks! Removed from area and dismantled, to be re-welded.

June 2001HARP Status – Chris Booth36 Cherenkov Mirror reflectivity 90% 700 nm300 nm mirror support mirror support PM + shielding PM + shielding Winston cone Winston cone

June 2001HARP Status – Chris Booth37 Time-Of-Flight wall 39 counters 2.5 cm thick BC408 ~7.4 m 2.5 m technical run prototype results: time difference between 2 counters 280 ps 420 ps 300 ps 200 ps

June 2001HARP Status – Chris Booth38 Electron and Muon identifier electron identifier muon identifier 6.72 m 3.3 m Electron identifier: Pb/fibre: 4/1 62 EM modules, 4 cm thick 80 HAD1 modules, 8 cm thick Muon identifier: Iron + scintillator slabs Thickness 6.44 I

June 2001HARP Status – Chris Booth39 Trigger: internal (sci-fibs) AND external RPCs AND TOF Outer Trigger 24 RPCs (TOF to support the TPC e/h separation ) Inner Fibre Trigger (Backward/Large angle) Forward RPCs …and far TOF plane (10 m distance) for small angle particles! Trigger system

June 2001HARP Status – Chris Booth40 Trigger counters TDS target defining scintillator disc, 2 cm , 5 mm thick, air light guides 4 photomultipliers >99.5 % efficiency per PM TDS target defining scintillator disc, 2 cm , 5 mm thick, air light guides 4 photomultipliers >99.5 % efficiency per PM ITC inner trigger cylinder surrounding the target 130 cm long, 7 cm  4 layers of 1 mm  scint. fibre viewed by 16 photomultipliers ITC inner trigger cylinder surrounding the target 130 cm long, 7 cm  4 layers of 1 mm  scint. fibre viewed by 16 photomultipliers beam trigger interaction trigger

June 2001HARP Status – Chris Booth41 Trigger counters 2 planes of 7 scintillation counters read out from both sides Total coverage 1.4  1.4 m 2 at the solenoid exit Forward trigger hodoscope (interaction trigger, together with RPCs) 6 cm hole for the outgoing beam 13/9/2000

June 2001HARP Status – Chris Booth42 Total Acceptance: 15 GeV  on Be TPC Forward Spectrometer A 4  experiment!!

June 2001HARP Status – Chris Booth43 p/  separation TPC TOF Cherenkov p/  separation at 4  level, “conservative” simplification P T -P L box-plot of  distribution from 15 GeV p on Be thin target

June 2001HARP Status – Chris Booth44 pions and protons; 2 GeV p on Be pionsprotons

June 2001HARP Status – Chris Booth45 HARP technical run

June 2001HARP Status – Chris Booth46 Secondary beam line Horizontal and Vertical Beam diameter (2  +2  ) for the extended T9 beam (simulated, without multiple scattering) Beam particle identification: 2 Cherenkov counters 2 TOF counters (dist. 24 m) ČČ B TOF A TOF HARP target

June 2001HARP Status – Chris Booth47 Beam optimization Measured beam sizes (  in mm) 1.28 m in front of HARP focus Multiple scattering effects at low momentum  = 10 mm

June 2001HARP Status – Chris Booth48 Beam particle identification raw data TOFA - TOFB versus Cherenkov-2 Time difference (ns) C2 (ADC counts) 1.4 ns nominal (p –  +) time difference A complete set of Cherenkov threshold values for all momenta was produced (Calculated + Measured) A complete set of Cherenkov threshold values for all momenta was produced (Calculated + Measured)

June 2001HARP Status – Chris Booth49 Beam chambers Argon ~65% CO 2 ~35% Argon ~65% CO 2 ~35% 4 MWPC with 1 mm (2 mm) wire spacing total ~800 readout channels Aim: tracking of incoming beam particles (~10 5 /spill) monitor beam halo and muon background analog chamber signals (20 mV, 50 ns) New! 50% Ar, 50% C0 2, trace H 2 O Lower threshold electronics >99.5% efficiency at lower voltage.

June 2001HARP Status – Chris Booth50 Drift chambers Beam profile, x hits of 1 plane Beam profile, x hits of 1 plane 19 cm ~680 ns Drift time  V D  47  m/ns Drift time  V D  47  m/ns Efficiency versus V anode 94% -spectrometer on -spectrometer off

June 2001HARP Status – Chris Booth51 Electron and Muon Identifier Raw data results from the technical run (single PM’s) Muon identifierElectron identifier ADC counts

June 2001HARP Status – Chris Booth52 HARP installation status Secondary beam lineFinished, tuned. Beam particle identificationFinished, calibrated. Incoming beam trackingReady; Halo monitor readout to debug. TriggerComplete; incorporating RPC. Solid targets Mech. support and first targets finished Cryogenic targets for summer TPC solenoid & spectrometer magnets Finished. TPC Under test in area. Flexi cables to repair on 4 sectors. RPCsInstalled on “dummy TPC”. Drift chambers68 of 69 planes working. Efficiency 90-95%. Gas CherenkovUnder repair. TOF wallInstalled, tested, operational. Electron & muon identifiersInstalled, tested, operational. Mid-June 2001

June 2001HARP Status – Chris Booth53 Remaining problems Cherenkov Counter Main frame delivered out-of-spec. Machined & corrected . Serious leaks. Re-weld box (25th June - 5th July). Test & purge (5 days); fill (5 days)  ready 15th July. TPC Break-down  field cage redesign . Warped pad boards fixed . Assembly complete; minor leaks to fix. Flexi micro-cables to repair on 4 sectors. Fill & test with 2 working sectors in parallel (15 days). Remove TPC, install final sectors, reinstall (5 days)  ready 10th July. Drift Chambers Efficiency with non-flammable gas only 90–95%. Revise reconstruction software to use individual hits rather than triplets. (Various algorithms under consideration.)

June 2001HARP Status – Chris Booth54 Software Process Stringent time schedule required adoption of software engineering standards. Software deliverables: –Project and Configuration Management Plans –User and Software Requirements Documents –Architectural Design Document & Design Diagrams –Test Plan and Release Procedures –Traceability matrixes across software deliverables Domains identification & dependency structure lead to: –definition of releasable units (libraries and source code), –definition of working groups (and schedules), –definition of ordering for unit & system testing and for release.

June 2001HARP Status – Chris Booth55 Software Functionality DAQ and detectors readout (DATE). Storage and retrieval of physics data and settings (Objectivity DB, AMS-HPSS interface). Framework including application manager, interfaces & data exchange for the components, and event model (GAUDI). Physics Simulation & Detector Model (GEANT4). Physics Reconstruction (of individual detectors). Online Monitoring & Offline Calibration of detectors. User Interface and Event Display (ROOT). Foundation libs & Utilities (STL, CLHEP).

June 2001HARP Status – Chris Booth56 Software architecture

June 2001HARP Status – Chris Booth57 DAQ DATE system Additions to DATE (ALICE DAQ prototype) framework: modifications to the event distribution algorithms in the Event Builder changes in the organization of data per spill (Physics trigger, SOB, EOB, SOR, EOR) Interfaces PCI-VME (latency problem with start of memory transfer) Alternative solutions are studied New VME hardware TDC V767, TDC V775, QDC 792

June 2001HARP Status – Chris Booth58 Example of data analysis Data processed through the complete software chain TOFB – TOFA time read by 35 ps resolution TDC Raw data p+p+ ++   =225 ps ++ p+p+   =200 ps Geom. corr. p+p+ ++   =135 ps + ADC corrected1.4 ns

June 2001HARP Status – Chris Booth59 Simulation

June 2001HARP Status – Chris Booth60 Simulation

June 2001HARP Status – Chris Booth61 Simulation

June 2001HARP Status – Chris Booth62 Event display

June 2001HARP Status – Chris Booth63 Reconstruction reconstructed drift chamber triplets (MC data)

June 2001HARP Status – Chris Booth64 Conclusion The HARP experiment has made considerable progress, but taking the full set of measurements will be a real challenge! We still have problems to overcome. Technical run 25/9/2000 – 25/10/2000 achievements: Beam line ready, including beam particle identification. Experimental area infrastructure. Both magnets (spectrometer, solenoid) installed and working. Many detectors installed and functioning. All essential software functionality (DAQ, storage, framework, simulation, reconstruction, monitoring, calibration, event display, library utilities). Current status of additional detectors: TOF wallInstalled and operational. RPCInstalled on dummy TPC. Electron identifierInstalled and working. CherenkovRe-welding to fix leaks. Ready 15th July. TPCRepairing micro-cable connections. Ready ~10th July. Cryogenic targetsJuly – August.

June 2001HARP Status – Chris Booth65 The HARP detector: Large Acceptance, PID Capabilities, Redundancy TPC, momentum and PID (dE/dX) at large P T TPC, momentum and PID (dE/dX) at large P T Drift Chambers: Tracking and low P T spectrometer Drift Chambers: Tracking and low P T spectrometer 1.5 T dipole spectrometer Threshold gas Cherenkov:  identification at large P L Threshold gas Cherenkov:  identification at large P L 0.7 T solenoidal coil Target-Trigger EM filter (beam muon ID and normalisation) EM filter (beam muon ID and normalisation) Drift Chambers: Tracking Drift Chambers: Tracking TOF:  identification in the low P L and low P T region TOF:  identification in the low P L and low P T region

June 2001HARP Status – Chris Booth66 Aim: hadronic d  /dP T /dP L - various beams and targets High statistics O(10 6 )/ “setting” & low systematic errors Goal: 2% accuracy over all phase space Stage I: proton/  beam in the range 2-15 GeV/c, multiple solid + cryo. targets Stage II: Additional (cryogenic) targets and additional Deuterium/Helium beam Stage III: GeV/c beams (SPS) What HARP can do in Summary:

June 2001HARP Status – Chris Booth67 Many thanks to..... LHC/ACR LHC/ECR (cryogenic targets) LHCb (GAUDI) TIS division (safety issues) ALICE (DATE system) NA49 (TPCino test setup) EP/ESS group (electronic pool) EP/ACD group (ITC construction) DELPHI (BC preamps) ALICE, NA49, ALEPH, DELPHI (TPC advice) EST division (alignment, cable mounting, gas supply, gas system, CERN workshops) EP/DED group (gas system) EP/ES group (electronics mounting and design) EP/ED group (TPC and RPC electronics) IT division (computing support, network) PS division (beam, experimental area infrastructure ) EP/EC group (magnets, field measurements and RPC) NA52 (TOF counters)ST division (transport, cooling, electricity, safety infrastr.) TA1 group (technical support, design, mirrors) SPL division (orders and CERN stores) GEANT4 collaboration Technical staff of home laboratories