北京航空航天大学核物理实验研究介绍 北京航空航天大学 核科学与技术系 2012 年 7 月

报告内容  北京航空航天大学核物理实验组简介  在 RIBLL1 上的一些实验设想

Search for Direct Evidence of Tensor Interactions in Nuclei  Measure the differential cross section of 12 C(p,d) 11 C and 16 O(p,d) 15 O reactions at deuteron angle θ d =0 degree using the RIBLL2 separator

 Use the FRS for producing secondary beams of 6 He and 6 Li and measuring 0 degree scattered deuterons by p( 6 He, d) 5 He and p( 6 Li, d) 5 Li reaction

School of Physics and Nuclear Energy Engineering Study of repulsive nature of optical potential for high energy 12 C+ 12 C elastic scattering (Effect of the tensor and three-body interactions)

Important role of masses of exotic nuclei in nuclear structrue and astrophysics. Precision mass measurements in storage rings in collobration with Lanzhou and Darmstadt. B. Sun et al., NPA 812 (2008) 1 Precision nuclear mass and half-life measurements in storage rings

TOF-P-E method Beihang & IMP (2012) Ultra-fast timing detector High precision position detector E-detector: MUSIC Towards more n-rich nuclei B  =  m 0 v/q

Magnetic rotation in the A=110mass Exotic motions of nucleus at high spin states (Magnetic rotation, Chiral rotation, Critical point symmetry) Magnetic rotation in the A=110 mass region : 112 In Chiral rotation in the A=110 mass region : 107 Ag Collaboration: China Institute of Atomic Energy Beihang University Shenzhen University Shandong University Peking University Collaboration: iThemba LABS, South Africa University of Stellenbosch Shandong University Peking University Beihang University… Search for chiral rotational bands in the A=80 mass region

 Reaction mechanism of weakly bound nuclei 在 RIBLL1 上的一些实验设想 The fusion cross sections may be strongly affected by channel coupling effects(inelastic, transfer and breakup), which are particularly important at sub-barrier energies. For strongly bound nuclei, which have very high breakup thresholds, coupling to the breakup channel plays a small role in fusion reactions. For light weakly bound nuclei(stable weakly bound nuclei 6,7 Li, 9 Be and unstable nuclei 6 He, 11 Be, 8 B), which have very low breakup threshold, can affect the fusion process. The different fusion process can take place. (1)direct complete fusion(DCF), which is analogous to fusion of strongly bound nuclei; (2)For weakly bound nuclei, the projectile is dissociated into two or more fragments as it approaches the target, the fragments are fully (SCF, sequential complete fusion)or partially(ICF, incomplete fusion) absorbed. CF=DCF+SCF, TF=CF+ICF For weakly bound nuclei, CF cross sections can be affected by two effects: (1)the long tail of density reduces the barrier height and changes the barrier curvature, lead to the enhancement of fusion; (2)maybe the strong dynamic effects arising from the coupling with the breakup channel, is harder to assess. L. F. Canto et al., Nucl. Phys. A 821 (2009) 51.

6 Li: S  =1.47MeV 7 Li: S  =2.47MeV 9 Be: S  =1.57MeV 8 Li: S n =2.033MeV 7 Be: S p =1.59MeV 6 He: S 2n =0.975MeV 8 B: S p =0.137MeV 17 F: S p =0.601MeV  Enhancement or hindrance? (1)CF cross sections is suppressed 10-30%, compared with those of CC(coupled channel) calculation which do not consider the breakup channel; (2)from TF cross section, didn’t show no appreciable effect; (3)CDCC calculation indicated that CF cross section is enhanced at energies much below the barrier and suppressed at energies well above the barrier. A. Barioni et al., Phys. Rev. C (2011)

G. L. Zhang et al., Eur. Phys. J. A 48, 65 (2012) M. Mazzocco et al., Phys. Rev. C (2010) P. R. S. Gomes et al., Phys. Rev. C (2005)

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J. M. B. Shorto et al., Phys. Lett. B 678 (2009) 77. G. L. Zhang et al., Eur. Phys. J. A 48, 65 (2012) J. C. Zamora et al., Phys. Rev. C 84, (2011)

J. M. B. Shorto et al., Phys. Lett. B 678 (2009) 77.

A. Di Pietro et al., Phys. Rev. Lett. 105, (2010) A. Di Pietro et al., Phys. Rev. C. 85, (2012)

K. Rusek et al., Acta Physica Polonica B, 43, 233 (2012)

 Structure of atomic nuclei with N~Z Sun, et al., Sci China-Phys Mech Astron, 54,210,(2010) Coulomb displacement energy Isobaric analogue states High spin structure Long-lived isomers

 Nuclear structure in 65 As: 65 Ge 65 As + Production by projectile fragmentation + Separation by RIBLL1 + Energy level scheme of 65 As + B(GT) strength + Possible isomeric state in 65 As + Isobaric analogue states ( 65 Ge, 65 As) + …

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