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!