1. Rare Isotope Science Project in Korea: RAON and nuclear theory
Youngman Kim
Rare Isotope Science Project (RISP)
Institute for Basic Science (IBS)
ECT*-APCTP workshop (Sept.14-18)

2. Outline
RISP in Korea
Theory activities at RISP

4. RAON Site Bird’s-eye view Area (Lot/Bldg): 952,066 m2 / 130,257 m2
Current RISP Office
~11 km

6. RAON Concept Driver LINAC Post Accelerator ISOL system IF system
High intensity RI beams by ISOL & IF
ISOL : direct fission of 238U by 70MeV proton
IF by 200MeV/u, 8.3pμA 238U
High quality neutron-rich RI beams
132Sn with up to ~250MeV/u, up to ~108 pps
More exotic RI beams by ISOL+IF
20m
ECR-IS (10keV/u, 12 pμA)
LEBT
128.5m
RFQ (300keV/u, 9.5 pμA)
MEBT
100m
SCL1 (18.5 MeV/u, 9.5 pμA)
Driver LINAC
Chg. Stripper
SCL2 (200 MeV/u, 8.3 pμA for U+79)
(600MeV, 660 μA for p)
375m
100m
80m
ISOL
Target
70m
20m
MEBT
RFQ CB
HRMS
IF Target
μSR,
Bio-medical
RF Cooler
SCL3
Cyclotron
(p, 70 MeV, 1mA)
250m
ECR-IS
High-precision
Mass Measurement
IF Separator
Gas Catcher
Post Accelerator
ISOL system
IF system
110m
100m
Low Energy Experiments
Nuclear Astrophysics
CB : Charge Breeder
HRMS : High Resolution Mass Separator
High Energy Experiments
Nuclear Structure/
Symmetry Energy

7. KOBRA (KOrea Broad acceptance Recoil spectrometer and Apparatus)
Main facility for nuclear structure and nuclear astrophysics studies
with low-energy stable and rare isotope beams
Main Research Subject :
1) Nuclear structure of exotic nuclei near the drip lines
2) Astrophysically important nuclear reactions
3) Rare event study - Super Heavy Element (SHE), New isotopes
4) Nuclear physics with polarized beam/target etc
- RIBs production
via low-E in-flight
method by multi
nucleon trasfer
reaction (ex. 44Ti)
- Main Specification
Maximum magnetic rigidity (Tm) ~3
Mass resolution stage 1
~700
Dispersion stage 1
4.2
Momentum acceptance stage 1 ±4
Angular acceptance stage 2
40 (H) and 200 (V)
Stage 1 F1 F2
Wien filter
Stage 2 F0
In-flight separation or
Beam transport
Wien filter
Big-bite
Spectrometer F3
* Design Concept
- Ion optics calculation was done using K-trace code (ray tracing)
- Rotation of ‘stage 2’, variable position of Q-magnets in ‘stage 2’
are under consideration
- Technical design is in progress F5
1) Two stage F4
- Stage 1 (F0~F3) :
- Design of associate equipment
Production and separation of RIBs via In-Flight method with high intensity
SIBs from SCL
* Associate equipments FP
Equipments F0
RI production target, F3
gas-jet target, gamma-array, detection system, b-NMR F5
Focal plane detection system
- Stage 2 (F3~F5) :
Big-bite spectrometer with Wien filter  large acceptance
[Gas-jet target]
[PPAC]
[Gamma array]

8. (Large Acceptance Multi-Purpose Spectrometer)
LAMPS
(Large Acceptance Multi-Purpose Spectrometer)
Asy-stiff
Asy-soft
Main facility for nuclear matter and nuclear reaction studies with intermediate energy stable and rare isotope beams
Main Research Subject:
Study of nuclear symmetry energy at supra-saturation density via heavy-ion collision experiment
L.W. Chen et al.,
PRL 94, (2005)
Beam Energy: up to 250 MeV/u
Solenoid Spectrometer
- Max. 1T solenoid magnet
- TPC (~ 3 sr acceptance,
charged particle tracking)
- Scintillation counter (trigger & ToF)
- Si-CsI (measure heavy fragment
using E-E method)
Dipole Spectrometer
- Rotatable dipole magnet and
focal plane detector
(capable to study nuclear reaction)
Neutron Wall (neutron tracking)

9. RISP Milestone Schedule
ECR SI Beam
RFQ Beam
SCL Demo Beam
SCL SI Beam
IF RI Beam
ISOL SI Beam
Cyclotron
ISOL RI Beam
DAY-1 Experiment
Begin Construction
Start Utility Supply
Completion

11. Theory activities at RISP; through international/domestic collaborations!
Boundaries of the nuclear landscape
Covariant density functional theory (Shuangquan Zhang) ...
Production of exotic nuclei and heavy elements
Reaction models (DNS, …), reactions for astrophysics
Equation of state of dense matter
New vibrational modes and asymmetric matter (Panagiota Papakonstantinou) ...
Symmetry energy of dense matter … (Mannque Rho, Friday)
Neutron stars (Chang-Hwan Lee, Thursday)
Nuclear structure and reactions from first principles
Ab initio NCSM ...
Unitarily transformed realistic interactions (Panagiota Papakonstantinou)
Nuclear transport: quantum molecular dynamics, RBUU (Yujeong
Lee, Thursday)
chiral effective field theory, …

12. Asymmetric matter in a parity doublet model
Introduce two nucleon fields that transform in a mirror way under chiral transformations:
“Linear sigma model with parity doubling,” C. E. DeTar and T. Kunihiro, Phys. Rev. D 39, 2805 (1989)

13. The state N+ is the nucleon N(938)
The state N+ is the nucleon N(938). while N- is its parity partner conventionally identified with N(1500).
Cf.

14. Parity doublet model with HLS
Motivation:
Lower m0 ?
Non-zero isospin density (chemical potential)
Lower Tc for (chiral) transitions?

15. Y. Motohiro, YK, M. Harada, PRC 92, 025201 (2015)

17. slope parameter
S0=31 MeV

19. Phase diagrams for m0 = 900 MeV
solid: first-order,
dashed: crossover
point: critical point (second order)
LGT: 1st 2nd
Critical chemical potential
drops a bit

20. Phase diagrams for m0 = 500 MeV
smaller m0 favors
smaller critical density for
chiral phase transition
both in symmetric and asymmetric
dense matter

21. Quantum Molecular Dynamics
Transport model : Model to treat non-equilibrium aspects of the temporal evolution of a collision.
Many-body problem with nucleons
Numerical simulation (event generator)
Different methods for different energies
Kyungil Kim (RISP), K. S. Lee (CNU), etc

22. Non-equilibrium aspects Equilibrated (decay statistically)
Time
~10-20 sec
~10-16 sec
Non-equilibrium aspects
Equilibrated (decay statistically) p n α
Transport model
QMD
BUU
Other model
HIPSE
DIT …
Statistical Model
GEMINI
SIMON
EMPIRE …

23. Initialization <Gaussian distribution>
σr, σp : widths in configuration and momentum
spaces, respectively
<Density distribution>
- Wood-Saxon function
d > 1.5 fm
<Fermi momentum>
<Pauli principle>
<Momentum of a nucleon>

24. Propagation Skyrme parametrization for NN potential
Ref.) M. Papa PRC 64(2010)024612
<Equation of Motion>

25. Stability
9Be
40Ca
<Propagation with stabilized nuclei>

26. N-N Collision In classical scattering, r1 𝑏< 𝑟 1 + 𝑟 2 b r2
Two particles are always scattered.
𝜎= π 𝑟 1 + 𝑟 2 2
In our model,
If a distance, d, between two nucleons is smaller than b, d<b, there is always a collision try.
Here, 𝝈 𝒕𝒐𝒕 is in-medium cross-section.
Ref.) G.Li and R.Machleidt PRC 48, 1702, PRC 49, 566

27. Pauli blocking <x-space> <p-space>
<Phase space density for i th particle>
Occupation number
After a nucleon-nucleon collision , we calculate the 6-dim. phase space density for each nucleon. If this condition for any nucleon is not satisfied, that collision will be blocked by the Pauli principle.

28. Central and Peripheral Collisions
b=0 fm
b=7 fm

29. Ab initio No Core Shell Model
Ab initio: nuclei from first principles using fundamental/realistic interactions without uncontrolled approximations.
No core: all nucleons are active, no inert core.
Shell model: harmonic oscillator basis
Point nucleons

32. Ab initio No Core Gamow Shell Model

33. Ab initio method and NN interaction
Unfortunately, the NN interaction at low energies needed for nuclear physics applications cannot be directly derived from QCD at the moment
Ab initio theory requires, of course, a realistic NN interaction accurately describing NN scattering data and deuteron properties
We use NNLOOPT and JISP16 in this study

34. 6Li in ab initio No Core Shell Model: NCFC approach
NCFC model is a version of the ab initio no core shell model (NCSM) with a few important characteristics:
(1) the use of interactions defined for an infinite Hilbert space,
(2) extrapolating to the continuum limit (infinite matrix limit)
(3) uncertainty estimation for the extrapolation.
In collaboration with:
Ik Jae Shin (RISP, IBS)
James Vary, Pieter Maris (Iowa State U.)
Christian Forssen (Chalmers U.), Jimmy Rotureau (FRIB, MSU)

35. converge more slowly,
underbound by 1.44 MeV ,
underbound only by 0.46 MeV

36. Both are within 2% of the experimental value

37. reasonable converged, about 3-5% higher than experiments

38. Results from Ab initio No Core GSM
Preliminary!!!
Energy of the ground state

39. Preliminary!!!
Energy of a resonance state (2+, 1)

40. Preliminary!!!
Imaginary part of the energy of (2+, 1) state

41. JISP16 vs Daejeon16 N3LO interaction ISTP
(inverse scattering tridiagonal potential)
SRG
(similarity renormalization group)
SRG-evolved N3LO
PET (phase equivalent transformation)
JISP16
(J-matrix inverse scattering potential)
Daejeon16
Ik Jae Shin (RISP, IBS), Andrey Shirokov (Moscow State U.)
James Vary (Iowa State U.), et al, in preparation

42. 6Li g.s. energy The results of stable nuclei seem to be improved.
N3LO-SRG
N3LO-SRG-PET (Daejeon16)
experimental value : MeV

43. 8He g.s. energy
Daejeon16 also gives reliable results even though for exotic nuclei.
N3LO-SRG
N3LO-SRG-PET (Daejeon16)
experimental value : MeV

44. Thank you for your attention !