In this work, a search for production of the superheavy elements with atomic numbers 119 and 120 was performed in the 50Ti + 249Bk and 50Ti + 249Cf fusion-evaporation reactions, respectively, at the gas-filled recoil separator TASCA at GSI Darmstadt, Germany. Over four months of irradiation, the 249Bk target partially decayed into 249Cf, which allowed for a simultaneous search for both elements. Neither was detected at cross-section sensitivity levels of 65 and 200 fb for the 50Ti + 249Bk and 50Ti + 249Cf reactions, respectively, at a midtarget beam energy of Elab = 281.5 MeV. The nonobservation of elements 119 and 120 is discussed within the concept of fusion-evaporation reactions including various theoretical predictions on the fission-barrier heights of superheavy nuclei in the region of the island of stability.
Khuyagbaatar, J., Yakushev, A., Düllmann, Ch. E., Ackermann, D., Andersson, L.-L., Asai, M., Block, M., Boll, R. A., Brand, H., Cox, D. M., Dasgupta, M., Derkx, X., Di Nitto, A., Eberhardt, K., Even, J., Evers, M., Fahlander, C., Forsberg, U., ... Yakusheva, V. (2020). Search for elements 119 and 120. Physical Review C, 102(6). https://doi.org/10.1103/physrevc.102.064602
Khuyagbaatar, J., Yakushev, A., Düllmann, Ch. E., et al., "Search for elements 119 and 120," Physical Review C 102, no. 6 (2020), https://doi.org/10.1103/physrevc.102.064602
@article{osti_1806438,
author = {Khuyagbaatar, J. and Yakushev, A. and Düllmann, Ch. E. and Ackermann, D. and Andersson, L.-L. and Asai, M. and Block, M. and Boll, R. A. and Brand, H. and Cox, D. M. and others},
title = {Search for elements 119 and 120},
annote = {In this work, a search for production of the superheavy elements with atomic numbers 119 and 120 was performed in the 50Ti + 249Bk and 50Ti + 249Cf fusion-evaporation reactions, respectively, at the gas-filled recoil separator TASCA at GSI Darmstadt, Germany. Over four months of irradiation, the 249Bk target partially decayed into 249Cf, which allowed for a simultaneous search for both elements. Neither was detected at cross-section sensitivity levels of 65 and 200 fb for the 50Ti + 249Bk and 50Ti + 249Cf reactions, respectively, at a midtarget beam energy of Elab = 281.5 MeV. The nonobservation of elements 119 and 120 is discussed within the concept of fusion-evaporation reactions including various theoretical predictions on the fission-barrier heights of superheavy nuclei in the region of the island of stability.},
doi = {10.1103/physrevc.102.064602},
url = {https://www.osti.gov/biblio/1806438},
journal = {Physical Review C},
issn = {ISSN 2469-9985},
number = {6},
volume = {102},
place = {United States},
publisher = {American Physical Society (APS)},
year = {2020},
month = {12}}
Khuyagbaatar, J.; Ackermann, D.; Andersson, L. -L.
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