Production of new neutron-rich isotopes near the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>N</mml:mi><mml:mo>=</mml:mo><mml:mn>60</mml:mn></mml:mrow></mml:math> isotones <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>Ge</mml:mi><mml:mprescripts/><mml:none/><mml:mn>92</mml:mn></mml:mmultiscripts></mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>As</mml:mi><mml:mprescripts/><mml:none/><mml:mn>93</mml:mn></mml:mmultiscripts></mml:math> by in-flight fission of a 345 MeV/nucleon <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi mathvariant="normal">U</mml:mi><mml:mprescripts/><mml:none/><mml:mn>238</mml:mn></mml:mmultiscripts></mml:math> beam
Y. Shimizu, T. Kubo, T. Sumikama, N. Fukuda, H. Takeda, Hiroaki Suzuki, D. S. Ahn, N. Inabe, K. Kusaka, M. Ohtake, Y. Yanagisawa, Kenichi Yoshida, Y. Ichikawa, T. Isobe, H. Otsu, Y. Satou, T. Sonoda, D. Murai, N. Iwasa, N. Imai, Y. Hirayama, Sohee Jeong, Shin‐ichi Kimura, H. Miyatake, M. Mukai, D. G. Kim, Eun‐jin Kim, A. Yagi
Abstract
A search for new neutron-rich isotopes near the $N=60$ isotones $^{92}\mathrm{Ge}$ and $^{93}\mathrm{As}$ has been performed using a 345 MeV/nucleon $^{238}\mathrm{U}$ beam at the RIKEN Nishina Center RI Beam Factory. Fission fragments produced were analyzed and identified in flight using the large-acceptance two-stage separator BigRIPS. We have observed a total of 15 new neutron-rich isotopes: $^{84}\mathrm{Cu}, ^{86,87}\mathrm{Zn}, ^{88,89}\mathrm{Ga}, ^{91,92}\mathrm{Ge}, ^{93,94,95}\mathrm{As}, ^{96,97}\mathrm{Se}, ^{99,100}\mathrm{Br}$, and $^{103}\mathrm{Kr}$.