Facility upgrade for superheavy-element research at RIKEN Hideyuki Sakai, Hiromitsu Haba, Kouji Morimoto and Naruhiko Sakamoto Eur. Phys. J. A, 58 12 (2022) 238 Published online: 09 December 2022 DOI: 10.1140/epja/s10050-022-00888-3