Progress of Experimental Nuclear

Astrophysics in CIAE

Wei-ping Liuwpliu@iris.ciae.ac.cn

China Institute of Atomic Energy (CIAE)CCAST symposium on physics of isospin

and nuclear phase transitionAugust 19-21, Beijing

Nuclear AstrophysicsFrom macro to microNuclear physics in energy production and element synthesisProcess, time scales, environment, isotope abundanceAstrophysical model

Some of the great discovery of astrophysics in 20th and 21th

century3K microwave background radiation,1965, experimental support for Big-Bang theoryDetection of solar neutrino, 1960, message from solar interiorElement distribution anomaly in metal starDetection of 26Al -ray, 1980, direct support of explosive nuclear synthesis, development of -ray astronomyDetection of SN1987A supernova explosion,1987Experimental explanation of solar neutrino missing, 2003

Exp The

Nuclear data

Astro Obs

Astro Model

Exp The

The interplay between nuclear physics and astrophysics

Abundance

Estimation

Nuclear physics plays role

®RIA white paper 2001

®RIKEN proposal

Important NP dataS-factor, focus on NP, down to astrophysicsReaction rates, direct input to network calculationDirect capture, direct reactionsResonance, level scheme, level width, and partial width

Where is reaction and decay data in network calculation

lkjijklAlkj

ilkj

kjijkAkj

ikjjj

j

ij

i

YYYVNN

YYVNNYNdt

dY

,22

,,,,

,,

,

Maxwellan dist. e-E/kT

Gamow peak

Coulomb penetratione-bE^(1/2)

Res. Peak

Prob

abilit

y

温度（能量）kT E0 Er

Extra low energies

0.2 0.25 0.3 0.35 0.4 0.45 0.5T9

100

150

200

250

300

350

yg

re

nE

ni

Vek

T9 vs. Gamow window

11C(p,)12N

General ideaProduction of RIB ( In-flight method)Measurement of (d,n) or (d,p) angular distribution Fit the distribution by DWBAGet ANC or spec factorUse ANC or spec factor to deduce (p,) astrophysical S-factor or (n,) reaction rate H. M. Xu, PRL 73(1994)2027

More basicsFor peripheral transfer

reaction: B(d,n)A two virtual captures:

B + p A n + p d

two ANC’s : ABpC

dnpCand

DWBAjljl

jnpljBpl

djnpl

AjBpl

ddAA

ddAA

ddAA

bb

CC

d

d 22

22 )()(

12 76.0)( fmC dnp

known value

2)( ABpC can be obtained from exp)(

dd

The Cross Section for E1 capture

22/1,

22

2

2

2

121

|)2()(|)(

)12)(12(

1);1(

rWkrfdrrCIjjk

e

TII

jjEB

f

N

ff

I

jI

R

IjjI

ffeff

m mImff

)( Ijj ff is the kinetic factor

eeff = eN/A for Protons

-eZ/A for Neutrons

ANC or spec factor

BRIF

Tandem: 15 MVCyclotron: 100 MeV p, 200A

RIBs expected

BIRFII

)(1,1

sin targetbeam1max AAlab

,labv

,CMlab

Cv

CMvmax

lab

labE

labE

maxlab

Inverse kinematics

GIRAFFE

Target Dipole

Quadrapoles

Reaction

Wien filter

W. Liu, NIMB 204(2003)62

Unstable beams produced

Secondary beams summary

Now, with velocity filter the new beam and beam purity enhancement:7Be, purity > 99 %17F, 15O, 13N, purity > 90 %10C, new beam, purity > 90 %With the future new beams of 14O and 8B etc by using 3He gas target

15 years of research in CIAE

95 2000 2005

7Be(d,n)8B, CIAE, PRL96, CPL2000

6He(p,n)6Li, CIAE, PLB2002

11C(d,n)12N, CIAE, NP2003

8Li(d,p)9Li, PRC2005

11C(p,)12N, TRIUMF

17F(d,n)18Ne, CIAE

Physics of 7BeThe astrophysical S factor for the 7Be(p,)8B reaction at solar energies is a crucial nuclear physics input for the “solar neutrino problem”. It was proposed that the S factor can be indirectly determined through the asymptotic normalization constant (ANC) extracted from the proton pickup reactions of 7Be, with an accuracy comparable to that from direct radiative capture or Coulomb Dissociation reaction.

Results － 7Be

W. LiuPRL77(1996)611NPA 616(1997)131c

Physics of 11CProton- and -capture reactions on proton-rich unstable nuclei of A≤13 involved in the hot pp chains are thought to be another alternative way to the 3 process for transforming material from the pp chains to the CNO nuclei in the peculiar astrophysical sites where the temperature and density are high enough so that the capture reaction becomes faster than the competing β decay These linking reactions between the nuclei in the pp chains and the CNO nuclei might be of immense importance for the evolution of massive stars with very low metallicities.One of the key reactions in the hot pp chains is the 11C(p,)12N which is believed to play an important role in the evolution of Pop Ⅲ stars.

From (d,n) to (p,g)

Results － 11C

W. Liu, NPA728(2003)275

11C(d,n)12N

E

Er MRSD

Network calculation

N. Shu, Nucl. Phys. A 758 (2005) 419c

E983@DRAGON

0.0 0.2 0.4 0.6 0.8 1.010-4

10-3

10-2

10-1

100

101

102

A

stro

ph

ysic

al S

-fa

cto

r (k

eV

b)

EC.M.

(MeV)

11C(p,)12N reaction

HCNO Novae

0.96, 2+

1.19 2-

CIAETAMUGANIL

RIKEN Coulmb dissociaion

Wiescher

Descouemont

Wei-ping Liu, E983 Proposal

Physics of 8LiInhomogeneous model predict that short-lived isotopes are created which allow for more reaction pathways to the heavier elementsReactions involving short-lived radioactive nucleus 8Li, 7Be and 8B play key role8Li generating reactions: 7Li(n,)8Li and 7Li(d,p)8Li ，8Li destroying reactions: 8Li(,n)11B, 8Li(n,)9Li, 8Li(d,p)9Li, 8Li(d,t)7Li, 8Li(d,n)9Be, etc. 8Li(,n)11B and 8Li(n,)9Li are key of them8Li has short half life of 0.83 s, so indirect approach is the only way to get (n,) rates

APJ429(1994)499

Results － 8Li

8Li(d,p)9Li

Ep

Z. H. Li, W. P. Liu et al., Phys. Rev. C 71, 052801(R) (2005)

Some details of calculation 1

In agreement with ANL results, A. H. Wuosmaa et al., PRL94(2005)082502, which is 0.90+ - 0.13

Some details of calculation 2

1

Fitted by experimental known 6,7Li and 12C (n,g) reactions

Results for (n,) rate

Z. H. Li, W. P. Liu et al., PHYSICAL REVIEW C 71, 052801(R) (2005)

Application to mirror system

Angular distribution 8Li(d,p)9Lig.s. @ Ecm = 7.8 MeV ANC of 9Li 8Li + n is 1.33 +-0.27 fm-1 Charge symmetry, ANC for 9C8B + p is 1.10 +-0.23 fm-1.S-factor and reaction rate for direct capture in 8B(p,g)9C using the ANC

B. Guo et al., Nucl. Phys., in press

Summary

Summary of experiments

1.33+-0.27 3970+-950

SummaryGIRAFFE, a tandem based one stage unstable beam facility proved to be effective to produce secondary beams suitable for the study of nuclear astrophysics reactions. Angular distribution measurements of transfer reaction in inverse kinematics, together with DWBA/ANC theoretical approach have been used to study the astrophysical reactions indirectly. The astrophysical S-factors and/or reaction rates for 7Be(p,)8B, 11C(p,)12N, 8Li(n,)9Li were deduced by using the measurements of 7Be(d,n)8B ,11C(d,n)12N, and 8Li(d,p)9Li reactions at the energies of astrophysical interest.

Research Team and support

Bing Guo

Gang Lian

Weiping Liu, wpliu@iris.ciae.ac.cn

Xixiang Bai

Baoxiang Wang

Sheng Zeng

Yun LuZhihong Li

Shengquan YanYongshou ChenNengchuan Shu

Kaisu Wu

Youbao Wang

Zhanwen Ma

Xiaodong Tang

NAO, U of Tokyo Toshitaka Kajino

CIAE

Zhanwen Ma

Research project supported by Ministry of science and technology, by National science foundation of China.