超重元素はどこまで存在するか : 質量公式からみた重・超重核領域の原子核崩壊  [in Japanese] How Far does the Area of Superheavy Elements Extend? : Decay Modes of Heavy and Superheavy Nuclei Predicted by a Mass Formula  [in Japanese]

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Author(s)

Abstract

近年盛んになっている超重元素合成実験において, より大きい原子番号の元素が発見されるに伴い, 原子核は一体どこまで存在するのであろうかという疑問が生じるのは自然なことであろう.軽・中重核領域の基底状態にある原子核の崩壊はβ崩壊が主であるのに比べて, 重・超重核領域ではα崩壊や自発核分裂に代表されるような多様な崩壊様式が重要になってくる.つまり, 原子核の存在領域の理解の鍵を握るのは超重核領域における核分裂であり, 現在, 原子核の微視的および巨視的な研究が進められている.本解説において重・超重核領域の崩壊様式についての全体像を示し, その存在領域についての一つの見解を示す.

Nuclear decay modes for heavy and superheavy nuclei are discussed with the use of a nuclear mass formula and some decay models. This mass formula, which we refer to as the KTUY formula, is composed of a gross part expressed as a smooth function of proton number and neutron number and a shell part calculated from single-particle potentials. On estimations of decay modes excluding spontaneous-fission, we use Q-values of the KTUY mass formula. The spontaneous fission half-lives are estimated from penetrability on a potential energy surface derived from a method of calculating shell energies of the KTUY mass formula. We indicate some regions of unknown nuclei with spontaneous-fission dominance and show the "island of stability" in the region of superheavy nuclei. We also point out a possibility of existence of another region of the island of stability beyond the superheavy region. In these regions, spontaneous-fission is very important to determine the border of existence of nuclei.

Journal

  • Butsuri

    Butsuri 60(9), 717-724, 2005-09-05

    The Physical Society of Japan (JPS)

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  • The Newly Observed 113th Element  [in Japanese]

    MORITA Kosuke

    Butsuri 60(9), 698-707, 2005-09-05

    J-STAGE  References (24) Cited by (2)

Cited by:  2

Codes

  • NII Article ID (NAID)
    110002079435
  • NII NACSIS-CAT ID (NCID)
    AN00196952
  • Text Lang
    JPN
  • Article Type
    Journal Article
  • ISSN
    00290181
  • NDL Article ID
    7419471
  • NDL Source Classification
    ZM35(科学技術--物理学)
  • NDL Call No.
    Z15-13
  • Data Source
    CJP  CJPref  NDL  NII-ELS 
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