Production of Element-106, Seaborgium, isotopes to apply for chemical research

原子序数为Z&gt；103的超重元素的化学性质研究是现代核化学和放射化学领域中极具挑战性的课题；这些元素的化学表征探索了元素周期表第7周期中元素的新前沿。然而，这些实验中的一些实验结果相互矛盾，另一些实验条件并不令人满意，因为严格限制了一次一个原子的实验条件。因此，用良好的统计数据获得准确的结果来表征这些元素的化学性质是非常重要的。为了研究Sg的化学性质，需要通过重离子核反应产生长寿命同位素^&lt；265,266&gt；Sg^&lt；248&gt；Cm^&lt；22&gt；Ne。然而，在JAEA串列加速器上生产^&lt；265,266&gt；Sg同位素是困难的，因为为气体喷射靶系统安装的真空窗不能稳定地用于穿越^&lt；22&>Ne产生的锐化光束。在本项目中，JAEA串列加速器的辐照束线上安装了一个新的束流摆动系统和一个用于气体喷射真空窗口的高流量氦冷却系统。经过这些改进，波束形状得到了成功铺展。19&gt；F束在3天内稳定可用，强度比我们之前的实验增加了三倍。最近，为了提高^&lt；19&gt；F和^&lt；22&gt；Ne的束流强度，在加速器中安装了一个新的ECR离子源(14 GHz)。在不久的将来，^&lt；22&gt；Ne束将用于生产Sg同位素用于化学研究。

Studies on chemical properties of the superheavy elements with atomic numbers Z>103 are extremely interesting and challenging subjects in the fields of modern nuclear and radiochemistry; chemical characterization of these elements explores the new frontiers of the elements in the 7th period of the Periodic Table. However, some of these experiments show conflicting results and some others are criticized due to unsatisfactory experimental conditions because of the strict restricted experimental conditions on an atom-at-a-time basis. Therefore, it is of great importance to obtain accurate results with good statistics to characterize chemical properties of those elements. To investigate the chemical properties of Sg, the long-life isotope, ^<265,266>Sg, is needed to produce by heavy-ion nuclear reaction, ^<248>Cm+ ^<22>Ne. However, it is difficult to produce ^<265,266>Sg isotopes in the JAEA tandem accelerator which facility was only reported the chemical studies of the superheavy element in Japan, since a installed vacuum window for a gas-jet target system will not stably use for crossing generated sharpen beams of ^<22>Ne. In this program, a new beam wobbling system and a high flow rate He-cooling system for the gas-jet vacuum window were installed in the irradiation beam line at the JAEA tandem accelerator. After these improvements, the beam shape was successfully spread out. The ^<19>F-beam was stably available during 3 days and the intensity was increased for three times as much as our previous experiments. Recently, in order to increase the ^<19>F and ^<22>Ne beam intensities, a new ECR ion-source (14 GHz) was installed in the accelerator. In the near future, ^<22>Ne beam will be used the Sg isotopes production for the chemical studies.