Recoil-α-fission and recoil-α-α-fission events observed in the reaction ⁴⁸Ca + ²⁴³Am

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• 作者：U. Forsberg^a ; ^{ulrika.forsberg@nuclear.lu.se" class="auth_mail" title="E-mail the corresponding author} ; D. Rudolph^a ; L.-L. Andersson^b ; A. Di Nitto^c ; Ch.E. Dü ; llmann^b ; ^c ; ^d ; C. Fahlander^a ; J.M. Gates^e ; P. Golubev^a ; K.E. Gregorich^e ; C.J. Gross^f ; R.-D. Herzberg^g ; F.P. He&szlig ; berger^b ; ^d ; J. Khuyagbaatar^b ; J.V. Kratz^c ; K. Rykaczewski^f ; L.G. Sarmiento^a ; M. Schä ; del^d ; ^h ; A. Yakushev^d ; S. &Aring ; berg^a ; D. Ackermann^d ; M. Block^b ; ^c ; ^d ; H. Brand^d ; B.G. Carlsson^a ; D. Cox^g ; X. Derkx^b ; ^c ; J. Dobaczewskiⁱ ; ^j ; K. Eberhardt^b ; ^c ; J. Even^b ; ¹ ; J. Gerl^d ; E. Jä ; ger^d ; B. Kindler^d ; J. Krier^d ; I. Kojouharov^d ; N. Kurz^d ; B. Lommel^d ; A. Mistry^g ; ² ; C. Mokry^b ; ^c ; W. Nazarewicz^f ; ⁱ ; ^k ; H. Nitsche^e ; J.P. Omtvedt^l ; P. Papadakis^g ; ³ ; I. Ragnarsson^a ; J. Runke^d ; H. Schaffner^d ; B. Schausten^d ; Yue Shi^f ; ^k ; P. Thö ; rle-Pospiech^b ; ^c ; T. Torres^d ; T. Traut^c ; N. Trautmann^c
• 关键词：Superheavy elements ; Element 115 ; Uup ; α decay ; Spontaneous fission
• 刊名：Nuclear Physics A
• 出版年：2016
• 出版时间：September 2016
• 年：2016
• 卷：953
• 期：Complete
• 页码：117-138
• 全文大小：639 K

文摘

Products of the fusion-evaporation reaction ⁴⁸Ca + ²⁴³Am were studied with the TASISpec set-up at the gas-filled separator TASCA at the GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany. Amongst the detected thirty correlated α  -decay chains associated with the production of element id="mmlsi1" class="mathmlsrc">ixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0375947416300768&_mathId=si1.gif&_user=111111111&_pii=S0375947416300768&_rdoc=1&_issn=03759474&md5=be5c29cffe61776148e6f964d8102456" title="Click to view the MathML source">Z=115iner hidden">i1.gif" overflow="scroll">i>Zi>=115, two recoil-α  -fission and five recoil-id="mmlsi2" class="mathmlsrc">ixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0375947416300768&_mathId=si2.gif&_user=111111111&_pii=S0375947416300768&_rdoc=1&_issn=03759474&md5=55a5e789b26d9d1ab29df3b6c8ba0a68" title="Click to view the MathML source">α–αiner hidden">i2.gif" overflow="scroll">i>αi>–i>αi>-fission events were observed. The latter five chains are similar to four such events reported from experiments performed at the Dubna gas-filled separator, and three such events reported from an experiment at the Berkeley gas-filled separator. The four chains observed at the Dubna gas-filled separator were assigned to start from the 2n-evaporation channel ²⁸⁹115 due to the fact that these recoil-id="mmlsi2" class="mathmlsrc">ixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0375947416300768&_mathId=si2.gif&_user=111111111&_pii=S0375947416300768&_rdoc=1&_issn=03759474&md5=55a5e789b26d9d1ab29df3b6c8ba0a68" title="Click to view the MathML source">α–αiner hidden">i2.gif" overflow="scroll">i>αi>–i>αi>-fission events were observed only at low excitation energies. Contrary to this interpretation, we suggest that some of these recoil-id="mmlsi2" class="mathmlsrc">ixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0375947416300768&_mathId=si2.gif&_user=111111111&_pii=S0375947416300768&_rdoc=1&_issn=03759474&md5=55a5e789b26d9d1ab29df3b6c8ba0a68" title="Click to view the MathML source">α–αiner hidden">i2.gif" overflow="scroll">i>αi>–i>αi>-fission decay chains, as well as some of the recoil-id="mmlsi2" class="mathmlsrc">ixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0375947416300768&_mathId=si2.gif&_user=111111111&_pii=S0375947416300768&_rdoc=1&_issn=03759474&md5=55a5e789b26d9d1ab29df3b6c8ba0a68" title="Click to view the MathML source">α–αiner hidden">i2.gif" overflow="scroll">i>αi>–i>αi>-fission and recoil-α-fission decay chains reported from Berkeley and in this article, start from the 3n-evaporation channel ²⁸⁸115.