奇异核的实验研究

总结了兰州放射性束实验小组在兰州放射性次级束流线上近几年来利用产生的放射性束流,轰击Si或C等靶子,测量它的反应总截面.并利用经验公式将这些结果归一到相同的能量和靶子,与其相邻的核相比较,发现了⁹C,¹¹Be,¹⁴Be,⁸B,¹⁴B 和¹²N等核素的反应总截面值有奇异增大的现象.利用微观的Glauber模型进行了计算,对有奇异结构的核采用核芯加价核子的密度分布形式,理论计算和实验结果符合得很好,可以给出奇异核的弥散的密度分布.

Experimental Study of the Exotic-Nuclei

These years the RIBLL(Radioactive Ion Beam Line in Lanzhou) group have measured many nuclei's total reaction cross sections, which is the most popular and simple way to identify the exotic nuclei. The experiments were completed by using transparency method. The experimental results of different nuclei at different energies were converted into the same energy (30MeV/nucleon) and same target (silicon) by Shen's formula. With comparing to their neighbors, we found that 9C, 11Be, 14Be,8B, 14B and 12N's results show larger ones. The Glauber model was used to calculate the total reaction cross sections, and 2-para-Fermi density distribution was introduced. For the exotic nuclei, a core plus exotic nucleons density distribution was used. The theoretical results are consistent with the experimental ones.