Efremov A, Bogomolov S, Mironov V
Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, Dubna, Moscow reg. 141980, Russia.
Rev Sci Instrum. 2020 Jan 1;91(1):013314. doi: 10.1063/1.5128172.
Since the early 1970s, attempts to synthesize Super Heavy Elements (SHE) have been made in many laboratories around the world. One of the main requirements of these experiments is a sufficiently large dose of target irradiation, which should be increased with a decrease in the reaction cross section. In this regard, the capacities of ion sources play an important role for the successful synthesis of SHE. At the FLNR JINR, the discovery and investigation of the new region of super heavy nuclei were based on fusion reactions of Ca with U-Cf target nuclei. In these experiments, a technique for the production of metallic Ca was developed. The operation mode of the ECR ion source was set to optimize the intensity of Ca ions and attain maximum ionization efficiency. Because of the heaviest target for experiments on synthesis of SHE in heavy ion reactions is Cf, so further progress in the synthesis of elements with Z > 118 requires the production of intense beams of accelerated neutron enriched isotopes, such as Ti, Fe, and Ni.
自20世纪70年代初以来，世界各地的许多实验室都在尝试合成超重元素（SHE）。这些实验的主要要求之一是要有足够大的靶辐照剂量，该剂量应随着反应截面的减小而增加。在这方面，离子源的性能对于超重元素的成功合成起着重要作用。在联合核研究所的弗廖罗夫核反应实验室，超重核新区域的发现和研究是基于钙与铀 - 锎靶核的聚变反应。在这些实验中，开发了一种生产金属钙的技术。设置了电子回旋共振（ECR）离子源的运行模式，以优化钙离子强度并实现最大电离效率。由于在重离子反应中合成超重元素的实验中最重的靶是锎，因此要在合成原子序数大于118的元素方面取得进一步进展，就需要产生高强度的加速富中子同位素束，如钛、铁和镍。
