From tomyo@rcnp.osaka-u.ac.jp Wed Jul  3 10:55:42 2002

-- Abstract --

In this work, the discrete g-rays emitted promptly from neutron capturing states of 84Kr, 20Ne and 22Ne were for the 
first time measured in the keV energy region. The measured cross section of the 84Kr(n,g)85Kr reaction is lower than the 
previous one by about 30 %. Concerning the Ne(n,g) reaction the discrete g-rays from the neutron capturing states of 20Ne 
and 22Ne have been observed for the first time and thus the Maxwellian-averaged cross sections were determined by 
considering the appropriate energy dependences. The measured cross sections of these isotopes of 20Ne and 22Ne are larger 
than previously measured values. Hence the present results could solve the problem of the discrepancy of 86Kr/82Kr ratio 
between the observed value and estimated one. It should be added that the non-resonant direct p-wave capture reaction 
process has been identified for the first time in the keV neutron capture reactions of Ne isotopes.

-- reference --

1.“A liquefier system for keV neutron radiative capture reactions of a
gaseous ample”,
  Y.Nobuhara, Y.Nagai, T.Shima, H.Makii, K.Mishima, A.Tomyo, K.Takaoka,
M.Kinoshita, Nucl. Instr. Meth. A437 (1999) 508-
515

2.“keV-Neutron Capture Cross Sections of Light Nuclei and
Nucleosynthesis”,
  T.Ohsaki, Y.Nagai, T.Shima, A.Tomyo et al., Proc. Int. Symp. Capture
Gamma-Ray Spectroscopy and Related Topics, ed. by 
S.Wender, Santa Fe, USA (1999) 458

3.“Neutron Capture Nucleosynthesis In AGB Stars”,
  R.Gallino, M.Busso, M.Lugaro, Astrophysical Implications of the Laboratory
Study of Presolar Materials. New York: AIP., 
115 (1997)

1及び2は実験方法に、3は恒星内元素合成の理論計算に関する参考文献。