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(p,g) reaction via transfer reaction of mirror nuclei and direct measurement of 11C(p,g)12N at DRAGON Bing Guo For nuclear astrophysics group China Institute of Atomic Energy The Sixth China Japan Joint Nuclear Physics Symposium May, 2006 Try to avoid too many color And I delete some pages to save the time, only when people ask for detail ,then you can answer.
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Content (p,g) reaction via transfer reaction of mirror nuclei.
1. Mirror symmetry 2. 8Li(d,p)9Li and 8B(p,g)9C 3. 26Mg(d,p)27Mg and 26Si(p,g)27P Direct measurement of 11C(p,g)12N at DRAGON. Try to use simple words, not full sentence, to make word larger, and say full sentences.
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Mirror symmetry A(d,p)B angular distribution
If A and C, B and D are mirror nuclei, then A(d,p)B angular distribution DWBA analysis Neutron ANC of virtual decay B → A + n Charge symmetry Proton ANC of virtual decay D → C + p and proton width Background is too general, try to use specific words. Radiative capture theory Astrophysical S-factor and rate of the C(p,g)D reaction
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Neutron ANC from A(d,p)B
is the ANC of d → p + n. is the ANC of B → A + n. L. D. Blokhintsev et al., Sov. J. Part. Nucl. 8, 485 (1977).
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Proton ANC and width of mirror nucleus D
BACK N. Timofeyuk et al., PRL. 91, (2003).
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8Li(d,p)9Li and 8B(p,g)9C Motivation:
8Li(d,p)9Li is one of important reactions in the inhomogeneous big bang models*, can serve as a surrogate reaction to extract the 8B(p,g)9C and 8Li(n,g)9Li reaction rates for the direct capture. *T. Kajino and R. N. Boyd, Astrophys. J. 359, 267 (1990).
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Secondary beam facility
Dipole Gas target Quadrupoles Wien Filter MCP1 MCP2 Reaction Chamber X. Bai et al., NPA 588, 273c (1995). W. Liu et al., NIM B204, 62 (2003).
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Experimental setup
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9Li particle identification
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Angular distribution of 8Li(d,p)9Li
s=7.9 ± 2.0 mb Z.H. Li, W.P. Liu, X.X. Bai, B. Guo et al., Phys. Rev. C 71, (R) (2005).
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8B(p,g)9C Motivation: 7Be(p,g)8B(p,g)9C(a,p)12N(b+)12C is one of possible alternative paths to 3a process; 8B(p,g)9C may play an important role in the evolution of massive stars with very low metallicities. M. Wiescher et al., Astrophys. J. 343, 352 (1989). G.M. Fuller et al., Astrophys. J. 307, 675 (1986).
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Current status and our proposal on 8B(p,g)9C
Several theoretical studies; Proton transfer 8B(d,n)9C reaction by RIKEN; Coulomb dissociation measurement by RIKEN; Knockout reactions of 9C by Texas A&M University and Michigan State University; Neutron transfer 8Li(d,p)9Li reaction and charge symmetry of mirror nuclei.
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8Li(d,p)9Li is peripheral?
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Astrophysical S-factor of 8B(p,g)9C
This work presents an independent examination to the existing studies. M. Wiescher et al., APJ. 343, 352 (1989). P. Descouvemont, NPA 646, 261 (1999). P. Mohr, PRC 67, (2003). D. Beaumel et al., PLB 514, 226 (2001). L. Trache et al., PRC 66, (2002). T. Motobayashi, NPA 719, 65c (2003). J. Enders et al., PRC 67, (2003).
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8B(p,g)9C reaction rate BACK
B. Guo, Z.H. Li, W.P. Liu et al., Nucl. Phys. A 761, 162 (2005).
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26Si(p,g)27P reaction 26Al 7.4×105 yr 5+ 26Mg The MeV g-ray is an ideal observable for nova and x-ray burst. J. José et al., Astrophys. J. 520, 347 (1999). O. Koike et al., Astron. Astrophys. 342, 464 (1999).
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Current status and our proposal on 26Si(p,g)27P
Several theoretical studies; Measurement of resonant capture via Coulomb dissociation method by RIKEN; No measurement of direct capture; Determination of direct and resonant captures through neutron transfer reaction 26Mg(d,p)27Mg and charge symmetry of mirror nuclei.
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Angular distribution of 26Mg(d,p)27Mg
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26Mg(d,p)27Mg is peripheral?
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ANCs of 27Mg and 27P 27P
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Proton widths for 27P H. Herndl et al., Phys. Rev. C 52, 1078 (1995).
J. A. Caggiano et al., Phys. Rev. C 64, (2001).
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Astrophysical S-factor of 26Si(p,g)27P
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26Si(p,g)27P reaction rate B. Guo, Z.H. Li, X.X. Bai et al., Phys. Rev. C 73, (2006).
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More reactions we can do
6Li(d,p)7Li → 6Li(p,g)7Be 7Li(d,p)8Li → 7Be(p,g)8B 11B(d,p)12B → 11C(p,g)12N 12C(d,p)13C → 12C(p,g)13N 13C(d,p)14C → 13N(p,g)14O 14N(d,p)15N → 14N(p,g)15O …… BACK
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Direct measurement of 11C(p,g)12N at DRAGON
Alternative way to the 3a process for transforming material from the pp chains to the CNO. Play an important role in the evolution of Pop Ⅲ stars. Indirect data have large discrepancies. Simple words, and put key reason.
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Existing indirect results of 11C(p,g)12N
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proposed by Prof. W.P. Liu
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Production of 11C ISOL approach(500 MeV proton) , successful producing beams such as 8,9,11Li, 21Na. Some difficulty producing beams of volatile elements such as 11C, 13N, 15O and 19Ne in required intensities (~108/s). Larger words.
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Alternative approach - using 13 MeV proton beam from TR13
Chemical or physical separation Transfer to OLIS Production OLIS ionization ISAC RB
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Sample radioactivity (mCi)
Intensity vs. collection time Beam of 11C were produced successfully. Beam intensity ~6×108 ions/s when 11C radioactivity of (1 Ci) produced by the TR13 medical cyclotron. Run No. Sample radioactivity (mCi) Beam intensity (ions/s) ECR efficiency 1 15.0 ± 1.5 (9.9 ± 0.4) ×106 (1.9 ± 0.2) %
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Conclusions of 11C production
Produce 11C (and other isotopes) without using the 500 MeV p+ beam is possible. The beam intensity can meet the needs of radiative proton capture study using DRAGON. The limitation is efficiency of the ion source. Use simple sentences, not copy from article. M. Trinczek, S. Lapi, B. Guo et al., Can. J. Phys., (in press).
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Research Team of Nuclear Astrophysics at CIAE
Experiment Xixiang Bai Bing Guo Gang Lian Zhihong Li Weiping Liu Jun Su Youbao Wang Baoxiang Wang Team members Shengquan Yan Sheng Zeng Yongshou Chen Nengchuan Shu Kaisu Wu Theoretical
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Thanks!
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