Theoretical study of synthesizing superheavy element using changes in shell structure caused by fusion dynamics

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K04003
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 15020:Experimental studies related to particle-, nuclear-, cosmic ray and astro-physics
• Research Institution: Kindai University
• Principal Investigator: Aritomo Yoshihiro 近畿大学, 理工学部, 教授 (90573147)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 新元素合成 / ニホニウム / 120番元素 / 動力学模型 / 殻構造 / 散逸揺動定理 / ランジュバン方程式 / 中性子過剰核

Outline of Final Research Achievements

In this study, by trajectory analysis using a dynamical model, we verified the mechanism by which complex nuclei in the spherical region can be formed via metastable states in the deformation region, and evaluated the cross section of the evaporation residue nucleus for superheavy element formation. The goal was to propose new experimental methods for new nucleosynthesis, and to propose the selection of target nuclei and incident nuclei, the optimal incident energies, and the generation cross sections. We performed the systematically calculation for the evaporative residual cross section and showed the feasibility of synthetic experiments for elements with atomic numbers of 119 and above. By repeating trajectory calculations and verifying the shell structure, which is important in the superheavy element region, we proposed the practical use of the "dynamic shell structure variation" that occurs in the fusion process.

Free Research Field

原子核理論

Academic Significance and Societal Importance of the Research Achievements

宇宙に存在できる最も重い元素の探求（人工的な合成）のため、ここでは次の新元素である原子番号119番以上の元素および安定な島の中心の二重魔法核の合成の成功を目指す。そのために、画期的な新しい反応機構を見つけ出し、新機構を利用した実験手法を提案する。現在計画されている実験手法は、従来の手法の延長線上の方法であり、加速器や検出器の性能の向上を図っても、将来にわたる長期的な新元素合成の成功に高い望みは持てない。理論研究の目的としては、融合過程における「動的な殻構造の変化」を最大限に利用した特異で新規な反応メカニズムを追求し明らかにすることである。