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Nuclear astrophysical reactions by unstable beams and Progress of BRIF and BRIFII 不稳定核束核天体物理反应 北京放射性核束装置的进展. Wei-ping Liu 柳卫平 wpliu@iris.ciae.ac.cn China Institute of Atomic Energy, CIAE 中国原子能科学研究院 6 th China Japan Joint Nuclear Physics Symposium 第六届中日核物理会议 May 16-20, 2006 Shanghai 上海.
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Nuclear astrophysical reactions by unstable beams andProgress of BRIF and BRIFII不稳定核束核天体物理反应北京放射性核束装置的进展 Wei-ping Liu 柳卫平 wpliu@iris.ciae.ac.cn China Institute of Atomic Energy, CIAE 中国原子能科学研究院 6th China Japan Joint Nuclear Physics Symposium 第六届中日核物理会议 May 16-20, 2006 Shanghai 上海
Study of some key nuclear astrophysical reactions by unstable nuclear beams
Interplay between astrophysics and nuclear physics Exp Exp The The Astro. Model Nucl. Data Astro. Obs. Abundance Dist. • Nuclear process • Main energy of star to balance gravitational collapse • Mechanism of isotope synthesis apart from Hydrogen • Rule the evolution process from the first few minutes after big bang to just before the end of star life • Nuclear astrophysics • Using nuclear physics to explain the energy production and element synthesis in star and cosmos
Nuclear astrophysics and physics of unstable nuclei • primordial and super novae high temperature and density environment, large amount of unstable nuclear involved into nuclear burning RIKEN RIBF proposal
Nuclear astrophysics ‘Lab’ B. Pfeiffer, et al., Z. Physik A357, 253 (1997)
Reaction network b g Cross section Decay half-life
Challenge to experiment 11C(p,)12N • Gamow window • Extremely low energy • Vanishing low cross section
Our solution: indirect method RIB production (d,n) or (d,p) measurement W.P. Liu, NIM B204(2003)62 W.P. Liu, PRL77(1996)611 Astrophysical reaction rates ANC or Spec factor
Direct capture process of 11C(p,g) • Key reaction in hot pp chain • Dominated by direct capture N. C. Shu,…, W. P. Liu et al., Nucl. Phys. A 758 (2005) 419c W. P. Liu et al., NPA728(2003)275
First measurement of primordial 8Li(n,g)9Li reaction rate • Destroy reaction of 8Li: 8Li(n,g)9Li, 8Li(d,p)9Li in inhomogeneous big bang,APJ429(1994)499 • Half-life of 8Li: 0.83 s,direct (n,g) exp. impossible Z. H. Li, W.P. Liu et al.,PRC 71, 052801(R) (2005)
Comment on our results • The paper presents excellent experimental work and removes a longstanding debate about the absolute cross section of 8Li(n,g) • As far as I know, so far, no results have been published to determine a neutron capture rate of astrophysical importance
13N(d,n)14O13N(p,g)14O PRC, submitted
Summary of reaction studied 18Ne 17F 14O 12N 9C
Opportunities from BRIF and BRIF II BRIF: Beijing Radioactive Ion Facility
Physics : why BRIF Intensity 1-109, energy 100 keV-10 MeV/u, RIA proposal
The current Tandem lab • Beam type, only stable, no noble gas • Energy range, less than 14 MeV/q • Instrumentation, no RMS, no ISOL • Beam time: 100 % overdue
BRIF 100 MeV 200 mA compact proton cyclotron 20000 mass resolution ISOL, 2 MeV/q super-conducting LINAC
BRIF research opportunities and combinations • 100 MeV neutron • ISOL • current terminals • limitation of instrument and machine time • Tandem with unstable beam, proton-rich, fission • heavy ion beam with higher beam energy, 20 MeV/q • 100 MeV proton and neutron beams • available by the year 2010 Ion Source Stable Beam 100 MeV, 200 mA Proton Cyclotron ISOL Mass Resolution 20000 Tandem Accelerator 15 MV Super Conducting LINAC RIB Nuclear data Radiation physics Nuclear structure Reaction Astrophysics Atomic Physics Applications Radiation physics Nuclear structure Reaction Astrophysics Atomic Physics Decay data Material physics Neutron data Radiation physics
More n-rich beam: CARRISOL • Horizontal tube • He-jet + ISOL • Neutron flux 1X1014 /cm2/s • Available in 2007
Low b RFQ for new injector 17 MeV/q super-conducting LINAC RMS Large acceptance spectrometer Decay measurements
RFQ/DTL 36MHz Low energy normal temp RFQ+ finger type DTL, multi charge heavy ion beam up to the energy accepted by SC LINAC
SC LINAC QWR • Energy gain 17 MeV/q • 36 ¼ wave length QWR • 9 100 L LHe tank LHe tank
Large acceptancespectrometer • Large D Q + detectors • Mass range 100-200,energy 5-10 MeV/u • Solid angle 80 mSr,P acceptance 10% • Mass resolution 300 via TOF and tracking
RMS 12 m Quadruples Quadruples Dipole Electro Deflector Electro Deflector Target chamber Detector chamber Beam diagnostics Beam diagnostics
Gamma array • 10X BGO+seg. HPGe • Eff. 10 % @ 1 MeV • resolution 6 keV
Research opportunities • Systematic study of shell evolution • Nuclear astrophysics • Mechanism of SHE • Properties of medium mass neutron rich nuclei • New decay modes • Gamma array • Recoil mass separator • Large acceptance spectrometer • Decay setup
Conclusion • BRIF and BRIFII will open up exciting research opportunities • With BRIFII: • new experimental terminals • higher beam energy of 35 MeV/q • 100 % more beam time by separate operation • Limit: overall instrumentation usage • Available by the year of 2013 • Chances are still open, and we welcome contributions, suggestions and new proposals • We would like to collaborate with major domestic and foreign research groups and world labs to take their full research potential and to do cooperative jobs • Call for user communities to build machine and detector and physics task force with more flexible way • A nice play ground in Beijing to connect locations