Nuclear Structure Studies at Beihang University (Collaboration with - - PowerPoint PPT Presentation

Nuclear Structure Studies at Beihang University

(Collaboration with RCNP) Isao Tanihata School of Physics and Nuclear Energy Engineering Beihang University and International Research Center for Nuclei and Particles in Cosmos

15年11月12日木曜日

School of Physics and Nuclear Energy Engineering

Physics Subjects at Beihang

✦

12C+12C elastic scattering and an effect of repulsive

three-body interaction

✦ Study of tensor forces in nuclei ✦ Spectroscopy at RIBF ✦ Determination of proton distribution radii of neutron

rich nuclei

✦ Charge exchange reaction of neutron-rich C isotopes

15年11月12日木曜日

12C+12C Optical potential with phenomenological

repulsive three-body interactions

• T. Furumoto, Y. Sakuragi, and Y. Yamamoto,
• Phys. Rev. C 82 (2010) 044612.

Study of Repulsive three-body interactions in heavy-ion collision (G.L. Zhang G.)

15年11月12日木曜日

12C+12C Optical potential with phenomenological

repulsive three-body interactions

• T. Furumoto, Y. Sakuragi, and Y. Yamamoto,
• Phys. Rev. C 82 (2010) 044612.

15年11月12日木曜日

The result at 100A MeV

Multi-Pomeron exchange potential with TBI

W.W. Qu, G.L. Zhang, S. Terashima,...

• T. Furumoto, Y. Yamamoto, H. Sakuragi et al.,
• Phys. Lett. B 751 (2015) 1.

without TBI CEG07b model with TBI

The angular distribution is better reproduced by the introduction of three-body repulsion.

15年11月12日木曜日

Effects of Tensor Forces in Nuclei (S. Terashima G.)

Please refer to the talk of S. Terashima

5 15年11月12日木曜日

Delayed coin. with 128Pd ions (Δt=0.15-25 μs) γ-γ coincidence with a gate on 1311 keV

Seniority isomer

• H. Watanabe et. al.,
• Phys. Rev. Lett. 111,

152501 (2013)

128 46 82

Pd

128Pd82

Spectroscopy of neutron rich nuclei at RIBF (H. Watanabe G)

15年11月12日木曜日

Delayed coin. with 128Pd ions (Δt=0.15-25 μs) γ-γ coincidence with a gate on 1311 keV

Seniority isomer

• H. Watanabe et. al.,
• Phys. Rev. Lett. 111,

152501 (2013)

128 46 82

Pd

128Pd82

15年11月12日木曜日

Delayed coin. with 128Pd ions (Δt=0.15-25 μs) γ-γ coincidence with a gate on 1311 keV

Seniority isomer

• H. Watanabe et. al.,
• Phys. Rev. Lett. 111,

152501 (2013)

128 46 82

Pd

128Pd82 130Cd82

A.Jungclaus et al., PRL 99, 132501 (2007) 15年11月12日木曜日

Delayed coin. with 128Pd ions (Δt=0.15-25 μs) γ-γ coincidence with a gate on 1311 keV

Seniority isomer

• H. Watanabe et. al.,
• Phys. Rev. Lett. 111,

152501 (2013)

B(E2;8+→6+) Seniority (ν) scheme

128 46 82

Pd

128Pd82 130Cd82

A.Jungclaus et al., PRL 99, 132501 (2007) 15年11月12日木曜日

Delayed coin. with 128Pd ions (Δt=0.15-25 μs) γ-γ coincidence with a gate on 1311 keV

Seniority isomer

• H. Watanabe et. al.,
• Phys. Rev. Lett. 111,

152501 (2013)

B(E2;8+→6+) Good ν=2 in the well isolated πg9/2 subshell Robust shell closure at N=82 Seniority (ν) scheme

128 46 82

Pd

128Pd82 130Cd82

A.Jungclaus et al., PRL 99, 132501 (2007) 15年11月12日木曜日

126Pd80 126Ag79

Long-lived isomer

✦ Ex = 2406 keV ✦ T1/2 = 23.0(8) ms ✦ Jπ = (10+) Rint = 26(8) % B(E3) = 0.07(2) W.u.

Decay schemes of the (10+) isomer and the ground state T1/2 average

★ 20.4(13) ms ★ 25.1(10) ms ★ 48.6(8) ms

• H. Watanabe et. al.,

PRL 113, 042502 (2014)

126 46 80

Pd

7- : ν(h11/2

• 1d3/2
• 1)

10+ : ν(h11/2)-2

15年11月12日木曜日

8

First CCCS Experiment at ETF

① Low energy site in general ② Atomic physics & nuclear astrophysics ③ SHANS - Spectrometer for Heavy Atom and Nuclear Structure ④ Heavy ion irradiation exp. site ⑤ RIBLL1 – 1st Radioactive Ion Beam Line in Lanzhou ⑥ ETF – External Target Facility ⑦ CSRe – Experimental Ring ⑧ PISA ⑨ Tumor therapy site

10 micro-beam

ECR

10

Measurement of charge changing cross sections(CCCS) and proton radii

• f neutron rich nuclei (B.-H. Sun G.)

15年11月12日木曜日

8

First CCCS Experiment at ETF

① Low energy site in general ② Atomic physics & nuclear astrophysics ③ SHANS - Spectrometer for Heavy Atom and Nuclear Structure ④ Heavy ion irradiation exp. site ⑤ RIBLL1 – 1st Radioactive Ion Beam Line in Lanzhou ⑥ ETF – External Target Facility ⑦ CSRe – Experimental Ring ⑧ PISA ⑨ Tumor therapy site

10 micro-beam

ECR

10

15年11月12日木曜日

9

Experiment setup

RIBLL2&(F0*F2)&+&ET& Experiment&@&IMP:&~&Jan.&24*28&2015

Slow extraction from CSRm Primary beam: 18O at 400 A MeV +CCCS Target: C(15 mm), Pb(3mm) + TOF-Bρ-dE for PID of RIBs +Plastic, Si for Z-identification +Beam tracking with MWPCs

18O

!!! = 1 ! !" Γ

!

Γ 1 ! !" N!"#

! N!" !

N!"#N!"

!

B.H. Sun(spokesperson)

• I. Tanihata (co-spokesperson)

15年11月12日木曜日

10

Setting @ 2014.01.20

CCCS measurements (Step 1)

colour coded from ADNDT99(2013)69

★: Identified in this work 4 different Bρ setting during ~ 4 days beam time New experiment scheduled around Jan. 2016 at IMP

15年11月12日木曜日

11

Sample data from 16N setting

TOF (ns)

120 121 122 123 124 125 126 127 128 129 130

dE (a.u.)

800 1000 1200 1400 1600 1800

16N 14C 12B 11B 13C 15N

Particle identification spectrum

Si2

500 1000 1500 2000 2500

Si1

500 1000 1500 2000 2500

Z-identification after target + above plastic scintillator is used for dE + Pileup rejection by: (1) Pile-up detection circuit. (2) Veto scintillator (3) Multi-hit TDC

Z

16N on C target

B.H. Sun, et al.

15年11月12日木曜日

12

!1

55 ..5/5.5051 .../1.5..5.0/..15..)

Ultra-high precision detector development

TDC TAC+ADC

500 MeV/u Fe at HIMAC

(//..51./.505.55 .5...5

a-ray

J.W. Zhao, B.H. Sun, et al. B.H. Sun, et al.

• I. Tanihata, et al.

High performance detector development for mass measurements and else.. (NSFC key project)

15年11月12日木曜日

12

!1

55 ..5/5.5051 .../1.5..5.0/..15..)

Ultra-high precision detector development

TDC TAC+ADC

500 MeV/u Fe at HIMAC

(//..51./.505.55 .5...5

a-ray

J.W. Zhao, B.H. Sun, et al. B.H. Sun, et al.

• I. Tanihata, et al.

15年11月12日木曜日

Charge Exchange Reactions of Neutron Rich Nuclei (GSI coll. G.)

13

New subject!

(p, n), (3He,t) reactions (charge exchange: Cex) at intermediate energy have been used to study Fermi and Gamow-Teller strength complementary with β-decay measurements. Cex reactions of neutron rich nuclei will give information

• n Fermi and Gamow-Teller strength for nuclei far from

the stability line.

15年11月12日木曜日

Relation between Cex cross section (σ) and β-decay strength (B(GT), B(F))

14

σ = ˆ σ iF

i(q,ω)B(i)

GV

2B(F)+ GA 2(GT) = K

ft

Unit cross section form factor=1 (q, ω)=(0,0) R = (GA /GV)2 = 1.56 ± 0.2 and K/(GV)2 = 6163 ± 4 s.

β decay and (p,n) (p,n) β-decay measurement become difficult

σF ~ 1/10σGT

Tadeucchi et al., Nucl. Phys. 469 (1987) 125.

• M. Sasano et al., Phys. Rev. C 79 (2009) 024602.

15年11月12日木曜日

Experiment with C isotopes (A=12-19)

15

AC + p -> A’N inclusive at 0 degrees

AC + p -> A+1N AC + p -> AN + n AC + p -> AN* + n -> A-xN + n +xn AC + p -> AN* + n -> A-y(7-y) + n +yp

15年11月12日木曜日

Experiment with C isotopes (A=12-19)

15

AC + p -> A’N inclusive at 0 degrees

AC + p -> A+1N AC + p -> AN + n AC + p -> AN* + n -> A-xN + n +xn AC + p -> AN* + n -> A-y(7-y) + n +yp

15年11月12日木曜日

Energetics of Transitions

16

N

A

C

A C+p

A-1

C+n

A-1

N+n

A-1

Qβ

M -M =0.782 MeV

S (N)

p

S (N)

n

S (C)

n

H

n

Sn : neutron separation energy Sp : proton separation energy Sn < Sp for neutron rich nuclei

For R-process nuclei: Sn ~ 1-2 MeV The window of Cex reaction is almost the same as β-decay window.

15年11月12日木曜日

Measurements

17

• Fig. 2 Experimental setup. Sci: plastic scintillation detector, TPC:

time-projection chamber, MUSIC: multi-sampling ion chamber.

15年11月12日木曜日

Data and comparisons

18

0.01 0.1 1 10 11 12 13 14 15 16 17 18 19 20 Cex cross section [mb] and sum(1/ft) [Arbitrary] Mass Number Α

σΖ=7 [mb]

β decay strength σΖ=7 [mb] and Σ(1/ft) normalized at A=12

β-decay data is not complete

15年11月12日木曜日

Data and comparisons

18

0.01 0.1 1 10 11 12 13 14 15 16 17 18 19 20 Cex cross section [mb] and sum(1/ft) [Arbitrary] Mass Number Α

σΖ=7 [mb]

β decay strength σΖ=7 [mb] and Σ(1/ft) normalized at A=12

β-decay data is not complete

Integrated strength of β transitions can be determined by Cex reaction.

15年11月12日木曜日

I have presented recent works at Beihang university. All experiments used intermediate- and high-energy beams. We are the group who has the most experience with high- energy heavy-ions and protons in nuclear physics. Beihang wish to contribute to HIAF physics! Thank you very much for your attention.

15年11月12日木曜日