Download - Status of the HARP Experiment
June 2001 HARP Status – Chris Booth 1
Status of the HARP Experiment
Chris Booth
University of Sheffield
June 2001 HARP Status – Chris Booth 2
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 2001 HARP Status – Chris Booth 3
Motivation – Neutrino Physics!
Conventional accelerator beamsp 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 2001 HARP Status – Chris Booth 4
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 2001 HARP Status – Chris Booth 5
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– ~1012 m–2yr–1 for 732 km baseline or ~1010 m–2yr–1 for 7332 km– Requires ~1021 muons per year– Requires ~1021 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 2001 HARP Status – Chris Booth 6
HARP: hadronic d/dPT/dPL at various beam energy and targets
June 2001 HARP Status – Chris Booth 7
Targets and pion capture
Two parameters are important:• pTmax determined by inner radius
of the capture solenoid• Acceptance of the RF-system
given by pL spectrum of pions
To optimise the target and capture system requires good knowledge of the pT and pL spectra to very low pT values.
June 2001 HARP Status – Chris Booth 8
Low Energy pion production
Observe pions and protons
June 2001 HARP Status – Chris Booth 9
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 12-24 GeV
Xlab =p/pbeam
June 2001 HARP Status – Chris Booth 10
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 PT
distribution
BUT the current simulation packages (FLUKA and MARS) show a 30%-100% discrepancies on pion yields
June 2001 HARP Status – Chris Booth 11
Università degli Studi e Sezione INFN, Bari, ItalyInstitut für Physik, Universität Dortmund, Germany
Joint Institute for Nuclear Research, JINR Dubna, RussiaUniversità degli Studi e Sezione INFN, Ferrara, Italy
CERN, Geneva, Switzerland Section de Physique, Université de Genève, SwitzerlandLaboratori Nazionali di Legnaro dell' INFN, Legnaro, Italy
Institut de Physique Nucléaire, UCL, Louvain-la-Neuve, BelgiumUniversità degli Studi e Sezione INFN, Milano, Italy
Institute for Nuclear Research, Moscow, RussiaUniversità "Federico II" e Sezione INFN, Napoli, Italy
Nuclear and Astrophysics Laboratory, University of Oxford, UKUniversità degli Studi e Sezione INFN, Padova, Italy
LPNHE, Université de Paris VI et VII, Paris, FranceInstitute for High Energy Physics, Protvino, Russia
Università "La Sapienza" e Sezione INFN Roma I, Roma, ItalyUniversità 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, BulgariaUniversità di Trieste e Sezione INFN, Trieste, Italy
Univ. de Valencia, Spain
HARP experiment PS214
22 institutes
107 authors
June 2001 HARP Status – Chris Booth 12
• Hadronic production cross sections (d/dPT,dPL)
at various energies and with various targets• Goal: 2% accuracy over all phase space
O(106) 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 1Measurements with solid and cryogenic targets, 2001 + early 2002
• Future plans:Measurements with incoming Deuterium and Helium, 2002~100 GeV incoming beam, using NA49 set-up
HARP will measure......
June 2001 HARP Status – Chris Booth 13
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 2001 HARP Status – Chris Booth 14
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 2001 HARP Status – Chris Booth 15
Parameters to optimise: proton energy, target material and target geometry, D2
• Proton beam 2-24 GeV
CERN: Linac 2 GeVBNL: Synch. 24 GeVFNAL: Synch. 16 GeV
Various high-Z Targets
• Li,Be,C,Al,Cu,liq.Hg etc.
(thin and thick)+/- ratio: • D2
beambackward-going pions • stopped muon
source
We Need new DATA
June 2001 HARP Status – Chris Booth 16
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 2001 HARP Status – Chris Booth 17
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 2001 HARP Status – Chris Booth 18
Experimental setup
drift chambers
Cherenkov
TOF wall electronidentifier
spectrometermagnet
TPC solenoidmagnet
forward triggerforward RPC
muonidentifier
beam
…-id at large pL
Tracking, low pT spectrometer
particle-id at low pL, low pT
High pT and particle-id
June 2001 HARP Status – Chris Booth 19
Targets – U.K. responsibility
Cryogenic targetsall 6 cm long
target tubetarget holder
target Z thinl (cm)
thickl (cm)
Be 4 0.81
C 6 0.76 38.0
Al 13 0.79 39.4
Cu 29 0.30 15.0
Sn 50 0.45
Ta 73 0.22 11.1
Pb 82 0.34 17.1
H2 D2 N2 O2
K2K target ~60 cm Al
MiniBooNE target
~65 cm Be
Solid targets
Special targets
> 99.99%
pure
June 2001 HARP Status – Chris Booth 20
Experimental setup
beam
TPC field cage
TPC pad plane/readout
target
ITC innertrigger cylinder
solenoid coil
RPC barrel
2.24 m
June 2001 HARP Status – Chris Booth 21
TPC
beam
1.59 m
PAD planereadout
HV plane~ 22 kV
“cork”(HV degrading +calibration systems)
Field cages
HARP
Stesalit wall (8 mm outer, 2 mm inner)
metallisation
June 2001 HARP Status – Chris Booth 22
TPC
Gate Wiring scheme
PAD size 6.515 mm2
20 PAD rows3972 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 wiresgating grid
all wiring around precisionpins on a 7 mm wide spoke-wheel gate wiring
32 cm
June 2001 HARP Status – Chris Booth 23
TPC
TPC calibration systems:•Mn source•Photo-emission from UV light (aluminised optical fibre)•Gate pulsing•Radioactive gas•Cosmics
Gas choice: 90% Ar, 10% CO2
Gas speed: 5 cm/sTotal drift time: 32 s 320 time samples at 10 MHzExpect around 1% of the 1.3106 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 2001 HARP Status – Chris Booth 24
TPCThe TPC design takes into account the results of many detailedsimulations/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 sharingWith field wires
Charge sharingWithout field wires
June 2001 HARP Status – Chris Booth 25
TPCTPCino prototypemini-TPC with 24 PADs•final wire configuration•90% Ar, 10% CO2•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 Functionmeasured with (point-like) -sourceand oscilloscope readout
TPCino Pad Response Functionmeasured with (point-like) -sourceand oscilloscope readout
June 2001 HARP Status – Chris Booth 26
TPC
HARP-TPCinoFull electronic chain Point-like photo emission source
preliminary:
pulseheight 10-14%
HARP-TPCinoFull electronic chain Point-like photo emission source
preliminary:
pulseheight 10-14%
June 2001 HARP Status – Chris Booth 27
TPC
TPCino test setup, full readout chain, online monitoring
FWHM of signal duration
200 nsscope view
of a single PAD10 MHz readout
30 s
June 2001 HARP Status – Chris Booth 28
RPCAdditional detector (not in the proposal)Particle (e – ) separation at low momenta (150 MeV – 250 MeV)<200 ps time resolution needed
can be achieved with RPC4 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) preamplifier8 PADs are added together after the amplifier stageSignal split into: trigger, TDC, ADCTotal 368 readout channels
June 2001 HARP Status – Chris Booth 29
RPC
Prototype results (T10 test beam)
= 104 ps
Time (TDC channel 50 ps)(30 ps trigger resolution still folded in)
June 2001 HARP Status – Chris Booth 30
Solenoid magnet
Gap radius 45 cm
Gap length 224 cm
Number of coils 88
Field strength 0.7 T
DC current 910 A
Power consumption
0.72 MW
Ex-ALEPH TPC90 magnetMagnet Requirements:• Homogeneous field in TPC (1.6 m long)• Br/Bz < 1%• Field strength 0.7 T• Downstream return yoke removed
Needed 50 cm extra length20 new coils of which 14 with a larger radius
new coils
June 2001 HARP Status – Chris Booth 31
Spectrometer magnet
Gap height 88 cm
Gap width 241 cm
Gap depth 171 cm
Field strength (vertical)
0.5 T
BdL 0.68 Tm
Current 2910 A
Power consumption 0.36 W
August 2000
August 2000
BdL 0.68 Tm
1 m
June 2001 HARP Status – Chris Booth 32
Spectrometer magnet
By (in y,z plane)
By (in x,z plane)
interpolation ofmagnetic field measurements
June 2001 HARP Status – Chris Booth 33
Drift chambers
23 chambers installed in HARP(69 planes)
Drift Chambers
32 mm drift length1 chamber = 1 triplet1 module = 4 chambers
wires at –5º, 0º, +5ºtotal 126 wires/chamber
8 mm gas gapgas:
90% Ar, 9% CO2, 1%
CH4
Read out by:CAEN TDC V767
June 2001 HARP Status – Chris Booth 34
Cherenkov
beam
5.4 m
2 rows of 19 PM's (8")in magnetic shieldingadditional focusing: Winston cones
Cherenkov box, 30
m3
filled with C4F10 gas
cylindrical mirror, 8
m2
curvature radius 2.4 m
2.6 GeV/c
K 9.3 GeV/c
p 17.6 GeV/c
threshold
June 2001 HARP Status – Chris Booth 35
C4F10 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 2001 HARP Status – Chris Booth 36
Cherenkov
Mirror reflectivityMirror reflectivity
90%
700 nm300 nm
mirrorsupport
mirrorsupport
PM + shielding
PM + shielding
Winstoncone
Winstoncone
June 2001 HARP Status – Chris Booth 37
Time-Of-Flight wall39 counters2.5 cm thick
BC408
~7.4 m
2.5 m
technical runprototype results:time difference between 2 counters
280 ps
420 ps
300 ps
200 ps
June 2001 HARP Status – Chris Booth 38
Electron and Muon identifier
electron identifier
muon identifier
6.72 m
3.3 m
Electron identifier:Pb/fibre: 4/162 EM modules, 4 cm thick80 HAD1 modules, 8 cm thick
Muon identifier:Iron + scintillator slabs
Thickness 6.44 I
June 2001 HARP Status – Chris Booth 39
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 2001 HARP Status – Chris Booth 40
Trigger counters
TDStarget defining scintillatordisc, 2 cm , 5 mm thick,air light guides4 photomultipliers>99.5 % efficiency per PM
TDStarget defining scintillatordisc, 2 cm , 5 mm thick,air light guides4 photomultipliers>99.5 % efficiency per PM
ITCinner trigger cylinder surrounding the target130 cm long, 7 cm 4 layers of 1 mm scint. fibreviewed by 16 photomultipliers
ITCinner trigger cylinder surrounding the target130 cm long, 7 cm 4 layers of 1 mm scint. fibreviewed by 16 photomultipliers
beam trigger
interactiontrigger
June 2001 HARP Status – Chris Booth 41
Trigger counters
2 planes of 7 scintillation countersread out from both sides
Total coverage 1.4 1.4 m2 at the solenoid exit
Forward trigger hodoscope(interaction trigger, together with RPCs)
6 cm hole for the outgoing beam
13/9/2000
June 2001 HARP Status – Chris Booth 42
Total Acceptance:
15 GeV on Be
TPC Forward Spectrometer
A 4 experiment!!
June 2001 HARP Status – Chris Booth 43
p/ separation
TPCTPC
TOFTOF
CherenkovCherenkov
p/ separation at 4 level, “conservative” simplification
PT-PL box-plot of distribution from 15 GeV p on Be thin target
June 2001 HARP Status – Chris Booth 44
pions and protons; 2 GeV p on Be
pions protons
June 2001 HARP Status – Chris Booth 45
HARP technical run
June 2001 HARP Status – Chris Booth 46
Secondary beam line
Horizontal and Vertical Beam diameter (2+2) for the extended T9 beam(simulated, without multiple scattering)
Beam particle identification:2 Cherenkov counters2 TOF counters (dist. 24 m)ČČ B
TOF
ATOF
HARPtarget
June 2001 HARP Status – Chris Booth 47
Beam optimization
Measured beam sizes ( in mm) 1.28 m in front of HARP focus
Multiple scattering effects at low momentum
= 10 mm
June 2001 HARP Status – Chris Booth 48
Beam particle identification
raw dataTOFA - TOFBversusCherenkov-2
Tim
e d
iffere
nce (
ns)
C2 (ADC counts)
1.4 ns nominal
(p – +) time difference
A complete set of Cherenkov thresholdvalues for all momenta was produced
(Calculated + Measured)
A complete set of Cherenkov thresholdvalues for all momenta was produced
(Calculated + Measured)
June 2001 HARP Status – Chris Booth 49
Beam chambers
Argon ~65%CO2 ~35%Argon ~65%CO2 ~35%
4 MWPC with 1 mm (2 mm) wire spacingtotal ~800 readout channels
Aim: • tracking of incoming beam particles (~105/spill)• monitor beam halo and muon background
analog chamber signals(20 mV, 50 ns)
New! 50% Ar, 50% C02, trace H2O
Lower threshold electronics>99.5% efficiency at lower voltage.
June 2001 HARP Status – Chris Booth 50
Drift chambers
Beam profile, xhits of 1 plane
Beam profile, xhits of 1 plane
19 cm
~680 ns
Drift time
VD 47
m/ns
Drift time
VD 47
m/ns
Efficiency versus
Vanode
94%
-spectrometer on-spectrometer off
June 2001 HARP Status – Chris Booth 51
Electron and Muon Identifier
Raw data results from the technical run(single PM’s)
Muon identifierElectron identifier
ADC countsADC counts
June 2001 HARP Status – Chris Booth 52
HARP installation status
Secondary beam line Finished, tuned.
Beam particle identification Finished, calibrated.
Incoming beam tracking Ready; Halo monitor readout to debug.
Trigger Complete; incorporating RPC.
Solid targets Mech. support and first targets finishedCryogenic targets for summer 2001.
TPC solenoid & spectrometer magnets
Finished.
TPC Under test in area. Flexi cables to repair on 4 sectors.
RPCs Installed on “dummy TPC”.
Drift chambers 68 of 69 planes working. Efficiency 90-95%.
Gas Cherenkov Under repair.
TOF wall Installed, tested, operational.
Electron & muon identifiers Installed, tested, operational.
Mid-June 2001
June 2001 HARP Status – Chris Booth 53
Remaining problemsCherenkov 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 2001 HARP Status – Chris Booth 54
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 2001 HARP Status – Chris Booth 55
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 2001 HARP Status – Chris Booth 56
Software architecture
Reconstruction Simulation ObjyPersistency
EventDisplay DetRep ObjectCnvObjyHarpEvent
HbookCnv HarpDD HarpEvent
Framework DAQ
ROOT(external lib)
GEANT4(external lib)
CLHEP Utilities STL DATE(external lib)
Objectivity(external lib)
HBOOK(external lib)
June 2001 HARP Status – Chris Booth 57
DAQDATE systemAdditions 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 2001 HARP Status – Chris Booth 58
Example of data analysisData processed through the complete software chain
TOFB – TOFA time read by 35 ps resolution TDCRaw data
p+
+
=225 ps
+
p+
=200 ps
Geom. corr.
p+
+
=135 ps
+ ADC corrected
1.4 ns
June 2001 HARP Status – Chris Booth 59
Simulation
June 2001 HARP Status – Chris Booth 60
Simulation
June 2001 HARP Status – Chris Booth 61
Simulation
June 2001 HARP Status – Chris Booth 62
Event display
June 2001 HARP Status – Chris Booth 63
Reconstruction
reconstructed drift chamber triplets (MC data)
June 2001 HARP Status – Chris Booth 64
ConclusionThe 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 wall Installed and operational.• RPC Installed on dummy TPC.• Electron identifier Installed and working.• Cherenkov Re-welding to fix leaks. Ready 15th July.• TPC Repairing micro-cable connections. Ready ~10th July.• Cryogenic targets July – August.
June 2001 HARP Status – Chris Booth 65
The HARP detector: Large Acceptance, PID Capabilities ,
Redundancy
TPC, momentum and PID (dE/dX)
at large PT
TPC, momentum and PID (dE/dX)
at large PT
Drift Chambers:Tracking and low
PT spectrometer
Drift Chambers:Tracking and low
PT spectrometer
1.5 T dipole spectrometer1.5 T dipole spectrometer
Threshold gas Cherenkov: identification
at large PL
Threshold gas Cherenkov: identification
at large PL
0.7 T solenoidal coil0.7 T solenoidal coil
Target-TriggerTarget-Trigger
EM filter (beammuon ID andnormalisation)
EM filter (beammuon ID andnormalisation)
Drift Chambers:Tracking
Drift Chambers:Tracking
TOF: identification
in the low PL
and low PT region
TOF: identification
in the low PL
and low PT region
June 2001 HARP Status – Chris Booth 66
Aim: hadronic d/dPT/dPL - various beams and targetsAim: hadronic d/dPT/dPL - various beams and targets
High statistics O(106)/ “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. targetsStage II: Additional (cryogenic) targets and additional Deuterium/Helium beamStage III: 15-100 GeV/c beams (SPS)
What HARP can do in Summary:
June 2001 HARP Status – Chris Booth 67
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