Production cross sections of projectile-like fragments in the Ca-48 + Ni-64 and Ca-48 + Ta-181 reactions at 70A MeV

Abstract

The particle stability of extremely neutron-rich nuclei close to the drip-line can be used for testing various mass predictions. For the efficient production of extremely neutron-rich nuclei, the target dependence on production rates of the projectile-like fragments with a 70A MeV Ca-48 beam has been investigated. In addition, an attempt to estimate cross sections and yields for Ne-33, Ne-34, and Na-36 and to argue their particle stability was made. To investigate the target dependence on production cross section, two energy-loss-equivalent production targets, Ni-64 and Ta-181, were used. By using the transmission calculated with the INTENSITY code, the production cross sections from the production rates of projectile-like fragments for N-(19-23), O(23-29), F(23-29), Ne(24-32), Na(29-35), Mg(34-38), and Al(35-41) were deduced. The production cross sections thus estimated are as follows; 1-6 pb for Ne-33, 0.6-3 pb for Ne-34, and 0.4-1 pb for Na-36.

極限線に近い極端な中性子過剰な核の安定性は色々な質量の予言の検証に使える。極端な中性子過剰な核を効果的に生成するために、70AMeVのCa-48ビームを使った破砕類似生成核の生成率の標的に対する依存性を調べた。さらに、Ne-33、Ne-34、そしてNa-36の断面積と収量の評価と、それらの粒子安定性の検討を試みた。生成断面積の標的依存性を調べるため、2種類のエネルギー損失が等しい生成標的、Ni-64とTa-181を使用した。INTENSITYコードで計算した透過率を使ってN(19-23)、O(23-29)、F(23-29)、Ne(24-32)、Na(29-35)、Mg(34-38)、そしてAl(35-41)の破砕生成核の生成断面積を求めた。また、こうして評価した生成断面積は、Ne-33について1-6pb、Ne-34について0.6-3pb、Na-36について0.4-1pbである。