Plan for LAMPS at KoRIA Byungsik Hong (Korea University) June 19, 2011 1 NuSYM 2011 Outline - Brief introduction to KoRIA - Physics of Symmetry Energy for Dense Matter - Design of LAMPS detector system - Summary The Second International Symposium on Nuclear Symmetry Energy Smith College, Northampton, Massachusetts, U.S.A., June 17-20, 2011
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Plan for LAMPS at KoRIA Byungsik Hong (Korea University) June 19, 20111NuSYM 2011 Outline - Brief introduction to KoRIA - Physics of Symmetry Energy for.
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NuSYM 2011 1
Plan for LAMPS at KoRIA
Byungsik Hong (Korea University)
June 19, 2011
Outline- Brief introduction to KoRIA- Physics of Symmetry Energy for Dense Matter- Design of LAMPS detector system- Summary
The Second International Symposium on Nuclear Symmetry EnergySmith College, Northampton, Massachusetts, U.S.A., June 17-20, 2011
NuSYM 2011 2
KoRIA: Korea Rare Isotope Accelerator
June 19, 2011
SCL
IFF LINACFuture extension
250 MeV/u, 9Ⅹ108pps(132Sn)200 MeV/u, 8pmA (U)
Stripper
28GHz SC ECR IS
Cyclotronp: 70/100MeV, 1mA
SCL RFQ SCL
H2
+D+
17.5 MeV/u
ISOL LINACSCL
ECR IS Fragment Separator
Nuclear Astro-physics
Material ScienceBio Science
Medical Sci-
ence
Low-energy experimentsAtomicPhysics
High-energyExperiments
(LAMPS)
ISOLTarget In-flight
Target
β=0.041, β=0.085 QWR QWR
β=0.285, β=0.53 HWR HWR
β=0.10 QWR
β=0.04 QWR
Nuclear Data
400KW
70KW
Stripper
Nuclear DataRFQ
Nuclear Physics
NuSYM 2011 3
Aim of Technical Specifi-cation
June 19, 2011
1. High-intensity RI beams by ISOL & IFF 70 kW ISOL from direct fission of 238U induced by 70 MeV
protons with the current of 1 mA
400 kW IFF by 200 MeV/u 238U with the current of 8pμA
E.g., 132Sn at ~250 MeV/u up to 9ⅹ108 pps (See next page)
2. More exotic RI beams by using multi-step RI production processes Combination of ISOL & IFF
3. Design Philosophy Simultaneous operational mode for maximal use of the
If the symmetry energy is too soft, then a mechanical insta-bility will occur when dP/dρ<0, neutron stars will, then, col-lapse.
oncondensatikaon
for critical is )(ρμe
G.Q. Li, C.-H. Lee & G.E. BrownNucl. Phys. A 625, 372 (1997)
eμ
Kμ
?TOV equation: a condition at hydrodynamical equilibrium
Gravity
Nuclear pressureFor npe matter,
dP/dρ<0, if E’sym is big and negative (super-soft)
)()1(2
1)()0,(
4
1)()()(
22
20
ρρEδδδρEδρEρ
μρρ
Eρρ,δPρPρ,δP
symsym
ee
δ
asy
)2(
4 3
g
g
mrr
PπrmPε
dr
dP
NuSYM 2011 13
Experimental Observ-ables
June 19, 2011
Signals at sub-saturation densities1)Sizes of n-skins for unstable nuclei2)n/p ratio of fast, pre-equilibrium nucleons3)Isospin fractionation and isoscaling in nuclear multifragmentation4)Isospin diffusion (transport)5)Differential collective flows (v1 & v2) of n and p
6)Correlation function of n and p7)3H/3He ratio, etc.
Signals at supra-saturation densities 1)p-/p+ ratio2)K+/K0 ratio (irrelevant to KoRIA energies)3)Differential collective flows (v1 & v2) of n and p
4)Azimuthal angle dependence of n/p ratio with respect to the R.P.Correlation of various observablesSimultaneous measurement of neutrons and charged particles
NuSYM 2011 14June 19, 2011
Soft
E sym
Stiff Esym
Central den-sity
More neutrons are emit-ted from the n-rich sys-tem and softer symme-try energies.
Yield Ratio
■n/p□3H/3He
610
500
)/(
)/(.
sym
.sym
ρρE
ρρE
M. A. Famiano et al. RPL 97, 052701 (2006)
Double ratio: min. systematic error
ImQMD
Y(n
)/Y(p
)
Esym(r)=12.7(r/r0)2/3+17.6(r/r0)gi
NuSYM 2011 15
Yield Ratio (π-/π+)
June 19, 2011
Data: FOPI Collaboration, Nucl. Phys. A 781, 459 (2007)IQMD: Eur. Phys. J. A 1, 151 (1998)
Need a symmetry energy softer than the above to make the pion produc-tionregion more neutron-rich!
2/3 0
00
2/3100 3(2corresponding t 1) ( )
5o ( )
8 FsymE E
NuSYM 2011 16
π-/π+ Ratio
June 19, 2011
Stiff Esym
Soft Esym
p- /p
+
(N/Z) reaction system
KoRIA,
etc
NuSYM 2011 17
Isospin Diffusion Parameter:Isospin Tracer
June 19, 2011
Isospin diffusion occurs only in asymmetric systems A+B
(No isospin diffusion between symmetric systems)
BBAA
BBAAAB
i NN
NNNR
2/)(
2
F. Rami et al., FOPI, PRL 84, 1120 (2000)B. Hong et al., FOPI, PRC 66, 034901 (2002)Y.-J. Kim & B. Hong, FOPI, To be pub-lished.
Ri = +1
Ri = 0 for
complete isospin mixing
Ri = -1
NuSYM 2011 18
Isospin Diffusion Param-eter
June 19, 2011
Projectile
Target
124Sn
112Sn
soft
stiff
Symmetry energy drives system towards equilibrium
stiff EOS : small diffusion (|Ri| ≫ 0)
soft EOS : large diffusion & fast equilibrium (Ri 0)
M.B. Tsang et al., PRL 92, 062701 (2004)
NuSYM 2011 19
Collective Flow
June 19, 2011
Stiff
SuperSoft
0
2
220
)(9
ρρ
symsym ρ
ρEρK
LargeN/Z
SmallN/Z
B.-A. Li, PRL 85, 4221 (2000)
Als
o k
now
n a
s v
1
NuSYM 2011 20
Design of Detector Sys-tem
1. We need to accommodate Large acceptance Precision measurement of momentum (or energy)
for variety of particle species including p+/- and neutrons with high efficiency
Keep flexibility for other physics topics in the future
2. This leads to the design of LAMPS Large-Acceptance Multipurpose Spectrometer
3. Unique features of LAMPS Combination of solenoid and dipole spectrometers Movable arms Large acceptance of neutron detector with preci-
sion energy measurementJune 19, 2011
NuSYM 2011 21June 19, 2011
•Dipole acceptance ~30mSr •Dipole length =1.0 m •TOF length ~8.0 m
Conceptual Design of LAMPS
Dipole magnet: We can also con-sider the large aperture super-conducting dipole magnet (SAMURAI type).
For B=1.5 T, p/Z ≈ 1.5 GeV/c at 30o
For B=1.5 T, p/Z ≈ 0.35 GeV/c at 110o
Neutron-detector arrayLow p/Z
High p/Z
Sole-noid
magnet
NuSYM 2011 22
Solenoid Spectrometer TPC: large acceptance (~3p Sr) for the measure-
ments of p+/- and light fragments Silicon strip detector: 3~4 layers for nuclear
fragments Useful for event characterization
June 19, 2011
NuSYM 2011 23
Dipole Spectrometer
June 19, 2011
Acceptance: > 50 mSr Multiparticle tracking of p,
d, t, and He isotopes, etc. Tracking chambers: ≥ 3
stations of drift chambers (+pad readout possible) for each arm
ToF: Conventional plastic scintillatior detector or multigap RPC technology– st < 100 ps, essential for
Dp/p < 10-3 @ b=0.5
NuSYM 2011 24
Simulated Event Display
June 19, 2011
IQMD(SM) for Au+Au at 250A MeV
NuSYM 2011 25
Simulated Event Display
June 19, 2011
IQMD(SM) for Au+Au at 250A MeV
Charged hadrons & fragments only
NuSYM 2011 26
Simulated Event Display
June 19, 2011
IQMD(SM) for Au+Au at 250A MeV
Neutral particles (g’s+neutrons) only
June 19, 2011 NuSYM 2011
Acceptance of LAMPS
27
p d t
4He p+ p-
Au+Au @ 250A MeV
June 19, 2011 NuSYM 2011
Acceptance of LAMPS
28
p d t
4He p+ p-
Au+Au @ 400A MeV
NuSYM 2011 29
Neutron-Detector Array
June 19, 2011
y
z
10 cm
100 cm
200 cm
50 cm
x
Important to measure neutrons simultane-ously with protons and fragments for the nu-clear symmetry energy
Important to measure wide range of the neu-tron energy
Large detector com-posed of scintillation slats for the veto and the neutron detectors
NuSYM 2011 30
Simulation: Veto Detec-tor
June 19, 2011
Neutron efficiency of neutron detector for various veto thresholds
Energy deposition as a function of proton energy for different thickness of veto de-tector
NuSYM 2011 31
Simulation: Neutron Detector
June 19, 2011
Assuming Perfect Time Resolution
Assuming st = 1.0 ns
Edet estimated by ToF
NuSYM 2011 32
Simulation: Neutron Detector
June 19, 2011
Energy Resolutions Tail Fractions
st = 0.0
nsst = 0.5
nsst = 1.0
ns
NuSYM 2011 33
Energy-Deposition Pro-files
June 19, 2011
count
neutron 100 MeV
MeV neutron 100 MeV
proton 100 MeV
proton 100 MeVgamma 100 MeV
gamma 100 MeV
countcount
MeVMeV
NuSYM 2011 34
Magnets
June 19, 2011
H-type dipolePole size: (x, z)=(150 cm, 100 cm)Maximum By: ~1.5 T (~4 T for SC op-tion)Gradient: 1.0 T∙m < ∫By∙dz < 2.0 T∙m
Solenoid Size (r, z) : (50 cm, 200 cm)Maximum Bz: about 1.0 T
by S. Hwang & J. K. Ahn
NuSYM 2011 35
Summary1. Korea Rare Isotope Accelerator (KoRIA)
Plan to deliver more exotic RI beams using multi-step pro-duction and acceleration processes
Keep the diverse operational modes
2. Large-Acceptance Multipurpose Spectrometer (LAMPS) Large acceptance Combination of solenoid and dipole spectrometers Movable arms Keep the flexibility for other physics topics in the future
3. Symmetry Energy in EoS Crucial to understand the neutron matter & several astro-
physical objects Long-standing, but yet to be solved problem in nuclear
physics LAMPS in KoRIA is willing to contribute to this effort.