The fragmentation reactions of neutron-rich unstable nuclei 81Ga and 82Ge at 250 MeV/nucleon have been studied in order to search the optimal mean for the production of very neutron-rich nuclei in the vicinity of 78Ni. The newly measured cross sections were compared with various calculations, showing a good agreement with EPAX3.01. The present work provides experimental insights into the two-step scheme—fragmentation following fission—as a method to produce very neutron-rich nuclei through a combination of ISOL and fragmentation of post-accelerated beams of unstable nuclei. Our results enable an evaluation of the potential of the two-step scheme in the production of very neutron-rich nuclei for the 78Ni region. The two-step scheme using fragmentation of a post-accelerated 81Ga beam could be an option to produce neutron-rich nuclei around 78Ni when the 81Ga beam intensity reaches 1.0×108 pps, compared to the one-step scheme with fission of 238U.

中文翻译：

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在 78Ni 附近产生富中子核：不稳定的 81Ga 和 82Ge 束流的碎裂反应


已经研究了富中子不稳定原子核 81Ga 和 82Ge 在 250 MeV/核子下的碎裂反应，以寻找在 78Ni 附近产生非常富含中子的原子核的最佳平均值。将新测量的横截面与各种计算结果进行比较，与 EPAX3.01 具有良好的一致性。目前的工作为两步方案（裂变后的碎裂）提供了实验见解，作为一种通过 ISOL 和不稳定原子核的后加速束碎裂的组合产生非常富含中子的原子核的方法。我们的结果能够评估两步方案在 78Ni 区产生非常富含中子的原子核的潜力。与 238U 裂变的一步方案相比，当 81Ga 束流强度达到 1.0×108 pps 时，使用后加速 81Ga 束流碎裂的两步方案可能是在 78Ni 周围产生富中子核的一种选择。