1 e05-115: third generation hypernuclear experiment hall c user meeting january 18th, 2008 (fri) yu...
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E05-115: Third Generation Hypernuclear Experiment
Hall C User MeetingJanuary 18th, 2008 (Fri)Yu FujiiTohoku Univ.
E05-115 : Spectroscopic investigation of hypernuclei in the wide mass region using the (e,e’K+) reaction
JLab E05–115 collaborators in proposal
~ 87 researchers from 19 institiutes
Dept. of Phys. Tohoku Univ.
Y. Fujii, O. Hashimoto, H. Kanda, M. Kaneta, D. Kawama, K. Maeda,
N. Maruyama, A. Matsumura, S.N. Nakamura, K. Nonaka, Y. Okayasu,
M. Sumihama, H. Tamura, K. Tsukada, Y. Miyagi
Dept. of Phys. Hampton Univ.
O.K. Baker, L. Cole, M. Christy, P. Gueye, C. Jayalath, C. Keppel,
S. Malace, E.K. Segbefia, L. Tang, V. Tvaskis, L. Yuan
Dept. of Phys. Florida International Univ.
A.Acha, W. Boeglin, L. Kramer, P. Markowitz, N. Perez, B. Raue,
J. Reinhold, R. Rivera
Dept. of Phys. Yamagata Univ.
S. Kato
Institute of Particle and Nuclear Physics (KEK)
H. Noumi, Y. Sato, T. Takahashi
Laboratory of Phys, Osaka Electro-Comm. Univ.
T. Motoba
Dept. of Phys. Univ. of Houston
Ed. V. Hungerford, K.J. Lan, Y. Li, N. Elhayari, S. Randeniya, N. Klantrains
Thomas Jefferson National Accelerator Facility
P. Bosted, R. Carlini, V. Dharmawardane, R. Ent, H. Fenker, D. Gaskell,
M. Jones, D. Mack, J. Roche, G. Smith, W. Vulcan, S. Wood, C. Yan
Yerevan Physics Institute
R. Asaturyan, H. Mkrtchyan, A. Margaryan, S. Stepanyan, V. Tadevosyan
Nuclear Physics InstituteLanzhou Univ.
X. Chen, B. Hu, S. Hu, Y. Song, W. Luo, B. Wang
Dept. of Physics / Applied Phys. Univ. of Zagreb
D. Androic, M. Furic, T. Petkovic, M. Planinic, T. Seva
Dept. of Phys. North Carolina A&T State Univ.
A. Ahmidouch, S. Danagoulian, A. Gasparian
Dept. of Phys. Louisiana Tech Univ.
N. Simicevic, S. Wells
Dept. of Phys. James Madison Univ.
G. Niculescu, M.-I. Niculescu
Dept. of Phys. Univ. of North Carolina at Wilmington
L. Gan
Dept. of Phys. Duke Univ.
M.W. Ahmed
Dept. of Phys. Univ. of Maryland
F. Benmokhtar, T. Horn
Dept. of Phys. Southern Univ. at New Orleans
M. Elaasar
Phys. and Astro. Dept. California State Univ.
Ed F. Gibson
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Introduction
p-shell nuclei : 6,7Li, 10,11B, 12C, (H2O for calibration)~ Fine structure ; core excited states etc. Baryon-baryon interaction in SU(3), charge symmetry breaking, coupling in large isospin hypernuclei cluster structure etc.
fp-shell nuclei : 40Ca(PR08-002), 51V, 52CrBeyond fp-shell : 89Y
~ Single-particle potential Distinguishability of a hyperon
U0(r), m*(r), ..
E05-115 : Λ Hypernuclear Spectroscopy
in the wide mass region
Layout of HKS-HES system in Hall-C
HKS
HES
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Setup of the 3rd generation experiment
HES (e’ arm) HKS (K arm)
Magnet Configuration Q-Q-D Q-Q-D
Central Momentum 0.55~1.0 GeV/c 1.2 GeV/c
Momentum Acceptance ±0.1 GeV/c ±0.15 GeV/c
Solid Angle 10 msr 8 msr
Resolution (FWHM) 2.0×10-4 2.0×10-4
Newly constructed
Etop1pass
(GeV)
Etop2pass
(GeV)
10.40.3 0.6 0.8
Ee’ (GeV)
2.51.8 1.9Ee at Hall-C
(GeV)
Acceptable Central Energy
(GeV)
HESENGE
2.0 2.2 2.4
4.4 4.55 5.0 6.0
9.45 10.3 10.8 12.0
2.1
Comparison of available beam energy betweenHKS+ENGE and HKS+HES
(2nd gen.)(3rd gen.)
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e’ from Bremss.
Moeller ring
e’ associatesWith virtual photon
Background
Signale’
Beam ( 1.8GeV ) Target e’-arm rate
1st Exp. (w/o tilt) 0.67 A 12C, 22 mg/cm2 200 MHz
2nd Exp. (w/ tilt) 30 A 12C, 100 mg/cm2 1 MHz
How to avoid background electrons ~Tilt Method~
Backgrounds on e’ arm : e’ from Bremss. & Moeller
→Tilt Method
x’
y’
2.5GeV Electron Beam Energy
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Acceptance of HESVirtual Photon Energy 1.5 GeV
Brems
Moller
Enge acceptance
x’
y’
2nd gen. (E01-011)
Enge 0.3 GeV/c
Beam Energy 1.8 GeV
HES acceptance
3rd gen. (E05-115)
HES 1.0 GeV/c
Beam Energy 2.5 GeV
×10
10 times virtual photon tagging efficiencyx’
y’
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HES detectors
e’
ED
EDC1
EHODO1,2
Detector Specifications
EDC1 (used in the 2nd Exp.)
Effective area 100W[cm] *12H[cm] *32T[cm]
Layers 10 (xx’, uu’, xx’, vv’, xx’)
Layer distance 7.5[cm]
Cell Size 0.5cm
EDC2 (same type as HKS DC) ; Hampton Univ.
Effective area 105W[cm] *30H[cm] *3.5T[cm]
Layers 6 (xx’, uu’, vv’)
Drift Distance 6.35mm
EHODO1 ; Tohoku U. 29 segments plastic scinti.
EHODO2 ; Tohoku U. 29 segments plastic scinti.
Position Detectors EDC1 ( Honeycomb type ) + EDC2 ( Planer type )Trigger Counters EHODO1 + EHODO2
EDC2
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Upgrade of HKS Detector package
• Renew boxes of Water Cherenkov ( Tohoku U.)– Improved light collection efficiency
• Add Lucite Cherenkov (Hampton U.)– Additional information on PID and TOF measurements
• Add bucking coil for Aerogel Cherenkov (Florida Int’l U.)– Cancel stray field of HKS dipole (~ 5 gauss) to recover gain of PMT
LC
RenewBucking Coil
Q-Q-D
Add
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Yield Estimation
Target
( 100mg/cm2 )
Yield for 100nb/sr [/hour]
E01-011 ( 1.8GeV, 24
A )E05-115 ( 2.5GeV, 30
A)
7Li ( 15A ) 9 48
10B 10 67
12C 10 56
40Ca ― 17
51V ― 13
89Y ― 7.5
about 5 times
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Simulated spectrum of 51V(e,e’K+)51Ti
HKS (8msr ) + HES⊿E = 300 keV [FWHM]Beam I = 30 [μA]V 100 [mg/cm2] S/N=5
Exp
ecte
d C
ou
nts
/100K
eV
/144h
- BΛ ( MeV )
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Pictures @ TOKIN (Sendai, Japan)
CEBAF 2.5GeV Electron Beam
SplitterSplitter
1.0GeV/c e’
1.2GeV/c K+
HESHESHESHES
HKSHKSHKSHKS
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Splitter Magnet
1.72 m
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Q-Q-D Magnet
EQ1EQ2
ED
EQ1EQ2
1.25 m
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Q-Q-D MagnetTilt Version
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Schedule
• Dec 2007 HES departed from Japan
• Feb 2008 HES arrives at Norfolk
• Mar 2008 Test experiment of detectors
at Tohoku Univ. (LNS)
• Apr 2008 Tohoku group begins stay at
JLab
By the end of 2008
Ready to install HES in Hall C
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Summary
• HES magnets are on the way to JLab
• HES detectors are under construction
• Part of HKS detectors, WC and AC will be
upgraded and LC will be added
• Yield is 5 times larger than the 2nd generation exp.
• Will be ready to install HES by the end of 2008
Various targetsVarious targetsE01-011 First GenerationE94-107 Hall A ExperimentE01-011 Second GenerationE05-115 Third Generation
PR08-002 Third Generation
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HES-HKS momentum acceptance
51Ti g.s
HKS
HES
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E01-011 Set Up