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Progress of Experimental Nuclear
Astrophysics in CIAE
Wei-ping [email protected]
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, [email protected]
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.