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Hadron Physics Programs at HIRFL-CSRm——Status and plan
Zhigang XiaoInstitute of Modern Physics, Chinese Academy of Sciences
Lanzhou 730000 China
QM 2006 Xi’an Satellite MeetingNov22-25 Xi’an, China
Collaborators:IMP: H. S. Xu, C. Zheng, N. Yao
R. R. Fan, Y. P. Zhang, J. J. LiangUSTC: X. DongCIAE: X. M. Li
Content
1 HIRFL-CSR complex2 Hadron Physics LanzhoU Spectrometer (HPLUS)3 Sub-detectors R&D in progress4 Summary
Physical Interests at CSR
Hadron and nucleon Physics (Hplus)
Nuclear Structure with RIB (Ext. Tar.)
Collision dynamics, EOS, high baryon density… (Ext. Tar.)
High charged atomic physicsHigh energy density physicsApplications (Irradiative, therapy )
HIRFL-CSR complex
ETE
HPLUS
Luminosity EstimationL=3×1031 /cm2/s
Xsection Evt.Rate
1nbar 10-2/s
1μbar 10/s
1mbar 104/s
50mbar 5×105/s
1 HIRFL-CSR complex2 Hadron Physics LanzhoU Spectrometer
2.1 Hadron Physics programs2.2 Concept of Hplus based on simulation
3 Sub-detector R&D in progress4 Summary
2.1 Hadron Physics programs
Hadron SpectroscopySymmetry Spin/isospin physics
Channels Threshold(GeV)
Physical interest
pp→ppφ→ppK+K−
2.593 Internal strange quark distribution and violation of symmetry
pp→pK+Σ (Λ→n+γ) 1.793(1.582)
Multi-quark states and strange constituent
pp→da0(980)(f0(980))
2.483 Mesons a0/f0 & internal quark-gluon structure
pp→ppK+K−
pd→ 3He K+K−2.4941.731
direct K production
pp→ppη (η′)pp→ppω
1.26(2.4)1.89
Isospin symmetry violation
pp→N*, Δ++(→KΛ…)
1.383 Baryon resonance
pα→N*α 0.795 Baryon excited states with Big σN coupling
pA→ρ(ω, η)pA→φ→ K+K−
Sub-threhold
Medium effect
2.2 Concept of HPLUS based on simulation
Channels in simulation
pp→ppφ→ppK+K-
pp→pN*(→KΛ…)
Phase space distributionFast trigger considerationConcept Real shapeTOF
TD
EMC
HC
Solenoid
Version 0
2.8GeV pp collision in Pythia
Proton
Pion+
gamma
Kaon+
Channel 1: pp pN*(1535)( K+Λ)
For Kaon:
P<2GeV
Angular: 80% in 30° (signal)
62% in 30° (bkg)
Channel 1: pp pN*( KΛ) decay products
Channel 2: pp ppφ( K+K-)
Forward region consideration: Physical channels
pp pN*( K+Λ)
pp ppφ*( K+K-)
Forward region consideration: background
pp pnπ
pp pp elastic
For EMC: Two gamma from π0
RM(CsI)=3.5cmθmin=7° Dmin=1m
Phase space distribution for charged particles
Dominant at forward sphere in laboratory.30° defines a good boundaryFor the channels above, K+ in forward angle could be used as a fast trigger.Distance of EMC to target: >1m
Current consideration of HPLUS
~90cm
~1.2m
~2.5m
~2.8m
EMC
TPC
FTD
TOF
YOKE
G4 based simulation platform
HPLUS
TPC
Det. Response
Det. Constr.
Data Store
HIT & Digi.
IO definitionIO implem.
IO
Det. Response
Det. Constr.
Data Store
HIT & DIGI
FTD
Track gene/store
Hit gen/store
MC Truth
Gmake env.
Gmake imple.External
Det. Response
Det. Response
Data Store
HIT & Digi
••••••
XML writer
Det. Install. DefGDML writer
TPC
FTD
••••••
Det. On/off
Phys. list
Field
Kernel
EventGenerator
Pythia generator
G4 Interface
Done
Doing
To do
1 HIRFL-CSR complex2 Hadron Physics LanzhoU Spectrometer3 Subdetector R&D in progress
3.1 CsI crystal3.2 MWDC
4 Summary
3.1 CsI crystals
Beam test:50 MeV/u 58Ni+Ta (93mg/cm2)CsI(Tl):size: 20×20 ×20 mm3
readout: PD
E
ΔE I
C
NiCo
FeMn
CrV
Ti
57Ni
• 138Cs source test:• light outputs: 20% higher than
Hamamatsu sample.
• Energy resolution: 5.1%
IMP3Φ 2×2 inch
IMP1Φ1×1 inch
IMP2Φ1×1 inch
3.2 MWDC: Prototype test
55 6 0 6 5 70 7 5
1 4 0
1 6 0
1 8 0
2 0 0
2 2 0 S im u la tio n
σ(μm
)
Σ σ
M e a s u re d
w ith o u t re s tr ic tio nw ith re s tr ic tio n
Single wire σ =13 μm
1520 1560 1600 1640 1680 1720
0.72
0.76
0.80
0.84
0.88
0.92
0.96
1.00
Laye
r Effi
cien
cy
Sense wire voltage
E=96%
Forward tracking ability
FTD improves resolution at forward regionWe need at least 5 pieces of MWDC
NFTD=5
4 Summary
HIRFL-CSR provides plenty opportunities forhadron physics research with 2.8GeV proton beam.HPLUS is on conceptual design stage. Design willbe focus at forward angle. High momentumresolution and high coverage for both chargedmesons and gamma are of importance.Full simulations for HPLUS have been started andneeds increasingly large investment. R&D of thecomponents are in process hierarchically .
Pellet target + polarized p/d target (future)
Maximum stored ions is 3× 1011,pellet explored at higher intensity, correspondingly, maximum luminosity is 1·1032
cm-2s-1 for pellet.
beam lifetime simulation
Proton beam lifetime ~ 400s at 2.8GeV
D= 1×1016 atoms/cm2
τ~400s
D= 4.8×1015 atoms/cm2
τ=900s
Luminosity Estimation
3×1031 /cm2/s
Xsection Evt.Rate
1nbar 10-2/s
1μbar 10/s
1mbar 104/s
50mbar 5×105/s
TPC FS: dE/dX vsSampling Layers
1GeV π+truncate at 3.5KeV
Sig:=width/MPVSampling up to 20
times, dE/dX Constant
3.3.2 PID for charged particles
dE/dX vs P
Ideal case: PID of π+ and K+ up to ~0.8GeV/cRegardless the large difference between the yield of π+/p and K+.
50 Samplings Landau + 5% Gaussian Electronic
fluctuation
Barrel – Short flight length
Typical flight length ~ 0.5m
Due to short flight length, TOF PID can’t extend the PID range of dE/dx much.
TOF-Barrel used as trigger detectors only
For high momentum particle identification, DIRC option.Challenge 1.
3.3.3 TPC resolution simulation
average ~1.5% momentum
resolution is possible
3.3.4 TPC under high event rateChallenge 2
Event time difference ~ 2μsFull drift time (1.5m TPC) 30 μsMulti-event multiplicity in TPC ~ 45Mean track Multiplicity/event in TPC
~3 Tracks rate in TPC 1.5×106/s
Possible solution: with the aid of TOF barrel to do event stampingSimulation going on
Necessity of forward tracking
TPC not sufficient for PID at forward region
Necessity of forward tracking
FTD improves resolution at forward region
Necessity of forward tracking
TPC ability weak at forward region
P
K
π
3.3.5 Necessity of forward tracking
FTD improves resolution at forward region
Outline of the simulation
Background and channel simulation shows that in lab most of products dominate at forward angle, design should focus at forward angle in labStrangeness meson used for fast triggerTPC not sufficient, FTD and long TOF time necessary
A later version of designOutlook Full simulation and final optimism
Increase manpower investment
§ 2.3 Simulations for HPLUS
2.3.1 Phase space distribution 2.3.2 PID ability of TPC / TOF2.3.3 Fast trigger, Necessity of forward tracking2.3.4 Recent consideration of HPLUS
3.3.6 pp→ppφ→ K+ K- with smeared momenta
3.3.7 G4 based simulation platform
HPLUS
TPC
Det. Response
Det. Constr.
Data Store
HIT & Digi.
IO definitionIO implem.
IO
Det. Response
Det. Constr.
Data Store
HIT & DIGI
FTD
Track gene/store
Hit gen/store
MC Truth
Gmake env.
Gmake imple.External
Det. Response
Det. Response
Data Store
HIT & Digi
••••••
XML writer
Det. Install. DefGDML writer
TPC
FTD
••••••
Det. On/off
Phys. list
Field
Kernel
EventGenerator
Pythia generator
G4 Interface
Done
Doing
To do
3 Projects in progress
3.1 CsI crystal growth, simulation and test3.2 Neutron Wall R&D3.3 Drift Chamber R&D
1 HIRFL-CSR complex2 Hadron Physics LanzhoU Spectrometer3 Projects in progress
3.1 CsI crystal growth, simulation and test3.2 Neutron Wall R&D3.3 Drift Chamber R&D
4 Summary
§4.1 CsI crystal growth /test
1020 crystal needed in EMC,δE/E ~3%φ11cm×35cmCsI crystal growth in IMP possible.Machining and test in progress
Uniformity test(190*60*50)
Uniformity:~3%(both sides)。
-2 0 2 4 6 8 10 12 14 16 18 201000
1100
1200
1300
1400
1500
C
hann
el
Position
Mean(B) Mean(A)
Efficiency SimulationSurface & decay length
Efficiency
No Surf. Reflectλ=35cm
22.8%
Full reflection λ= 35cm
31.5%
Full reflection λ= 60cm
51.3%
Full reflection λ= 120cm
81%
Single scintillator simulation going on
To do: EMC construction and simulation
§ 4.2 Neutron Wall R&D
Active area 1.5×1.5m2
Thickness 1m
Acceptance ±3.80
coverage 11~20 mSr
Angular resolution 0.30
Efficiency (1GeV n) >90%
Position resolution ±8cm
E resolution(<1GeV n) ≤5 %
Design and structure
1000
1500
1500
Neutron
Calorimeter unit consistence and test
CU: 5 scintillator layers + 6 absorber layers12 CU in total
Coupling
Steel Scintillator
TriggerR7724 Start
Prototype test/simulation results
Real Test
Simulation
Scintillator : σ<80 Calorimeter: σ<100
Test results
<Np>~6, <Nw>~1
Drift time
0
20
40
60
80
100
120
140
160IDEntriesMeanRMS
201 18269
2220. 474.4
D:\DWPC\FF5\MUON03_05.RZD
0
5
10
15
20
25
30
35
40
45
50
1500 1750 2000 2250 2500 2750 3000 3250 3500
IDEntriesMeanRMS
202 2176
1934. 304.1
layer hit multiplicity per event
0
100
200
300
400
500
600
700
800
900
-1 0 1 2 3 4 5 6 7 8
IDEntriesMeanRMS
55 959
1.113 0.6457
51.R
fired layer multiplicity per event
0
100
200
300
400
500
600
700
800
0 2 4 6 8 10 12
IDEntriesMeanRMS
20 972
5.684 0.7028
51.R
Nw fired /plane
Np fired /event
Efficiency and resolution
~96% efficiency<200μm position resolution
1520 1560 1600 1640 1680 1720
0.72
0.76
0.80
0.84
0.88
0.92
0.96
1.00
Laye
r Effi
cien
cy
Sense wire voltage
Track-hit Residual
0
20
40
60
80
100
120
140
160
-200 -100 0 100 200
IDEntriesMeanRMS
61 892
1.404 27.81
101.2 / 43Constant 118.4Mean -0.9617Sigma 13.28
51.R
55 60 65 70 75
140
160
180
200
220 Simulation
σ(μ
m)
Σσ
Measured
without restrictionwith restriction
Single wire σ =13 μm
5 Summary
HIRFL-CSR provides plenty opportunities for hadron andnuclear physics research at 1AGeV region.HPLUS is on late conceptual stage. Fast simulation is going
on and likely supports current configuration. PID for highmomentum particles and TPC running at high event rate aretwo challenges.Full simulations for HPLUS have been started and needsincreasingly large investment. R&D of the components forboth experiments are processing hierarchically .
Thank you!