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

Ca + Am反応で観測された反跳核--核分裂及び反跳核---核分裂相関事象

Forsberg, U.*; Rudolph, D.*; Andersson, L.-L.*; Di Nitto, A.*; Dllmann, Ch. E.*; Fahlander, C.*; Gates, J. M.*; Golubev, P.*; Gregorich, K. E.*; Gross, C. J.*; Herzberg, R.-D.*; Heberger, F. P.*; Khuyagbaatar, J.*; Kratz, J. V.*; Rykaczewski, K.*; Sarmiento, L. G.*; Schdel, M.; Yakushev, A.*; berg, S.*; Ackermann, D.*; Block, M.*; Brand, H.*; Carlsson, B. G.*; Cox, D.*; Derkx, X.*; Dobaczewski, J.*; Eberhardt, K.*; Even, J.*; Gerl, J.*; Jger, E.*; Kindler, B.*; Krier, J.*; Kojouharov, I.*; Kurz, N.*; Lommel, B.*; Mistry, A.*; Mokry, C.*; Nazarewicz, W.*; Nitsche, H.*; Omtvedt, J. P.*; Papadakis, P.*; Ragnarsson, I.*; Runke, J.*; Schaffner, H.*; Schausten, B.*; Shi, Y.*; Thrle-Pospiech, P.*; Torres, T.*; Traut, T.*; Trautmann, N.*; Trler, A.*; Ward, A.*; Ward, D. E.*; Wiehl, N.*

Forsberg, U.*; Rudolph, D.*; Andersson, L.-L.*; Di Nitto, A.*; Dllmann, Ch. E.*; Fahlander, C.*; Gates, J. M.*; Golubev, P.*; Gregorich, K. E.*; Gross, C. J.*; Herzberg, R.-D.*; Heberger, F. P.*; Khuyagbaatar, J.*; Kratz, J. V.*; Rykaczewski, K.*; Sarmiento, L. G.*; Schdel, M.; Yakushev, A.*; berg, S.*; Ackermann, D.*; Block, M.*; Brand, H.*; Carlsson, B. G.*; Cox, D.*; Derkx, X.*; Dobaczewski, J.*; Eberhardt, K.*; Even, J.*; Gerl, J.*; Jger, E.*; Kindler, B.*; Krier, J.*; Kojouharov, I.*; Kurz, N.*; Lommel, B.*; Mistry, A.*; Mokry, C.*; Nazarewicz, W.*; Nitsche, H.*; Omtvedt, J. P.*; Papadakis, P.*; Ragnarsson, I.*; Runke, J.*; Schaffner, H.*; Schausten, B.*; Shi, Y.*; Thrle-Pospiech, P.*; Torres, T.*; Traut, T.*; Trautmann, N.*; Trler, A.*; Ward, A.*; Ward, D. E.*; Wiehl, N.*

Ca + Am反応による115番元素合成実験で観測された崩壊連鎖について、最近我々が報告したドイツGSIで測定したデータと過去に報告されたロシアDubna及び米国LBNLで測定されたデータのすべてを使い、その起源を調査した。それらのデータの中に、反跳核--()-核分裂タイプの短い崩壊連鎖が14事象観測されており、そのうちのいくつかは中性子が2個放出されてできるMc起源であるとこれまで解釈されてきた。一方、今回我々は、これらの短い崩壊連鎖のほとんどが、中性子が3個放出されてできるMc起源であり、崩壊連鎖の途中でEC崩壊して核分裂したものであろうと再同定した。

Alpha-decay chains observed in the element-115 production reactions of Ca + Am were investigated using a new data set consisting of our recently reported data obtained at GSI and previously reported ones at Dubna and LBNL. Short decay chains of recoil--()-fission type, fourteen of which were observed, and some of which were interpreted as the 2-neutron evaporation products Mc, have been reassigned. It is plausible that most of them were assigned to the 3-neutron evaporation products Mc whose decay chain would on the way have branches of EC decays followed by fission.