Production cross section and decay study of $^{243}$Es and $^{249}$Md

R. Briselet (1) , Ch. Theisen (1) , M. Vandebrouck (1) , A. Marchix (1) , M. Airiau (1) , K. Auranen , H. Badran , D. Boilley (2, 3) , T. Calverley , D. Cox , F. Déchery (1, 4) , F. Defranchi Bisso (5) , A. Drouart (1) , B. Gall (4) , T. Goigoux (1) , T. Grahn (5) , P.T. Greenlees (5) , K. Hauschild (6) , A. Herzan (5) , R.D. Herzberg (7) , U. Jakobsson (5) , R. Julin (5) , S. Juutinen (5) , J. Konki (5) , M. Leino (5) , A. Lightfoot (5) , A. Lopez-Martens (6) , A. Mistry (7) , P. Nieminen (5) , J. Pakarinen (5) , P. Papadakis (5) , J. Partanen (5) , P. Peura (5) , P. Rahkila (5) , J. Rubert (4) , P. Ruotsalainen (5) , M. Sandzelius (5) , J. Saren (5) , C. Scholey (5) , J. Sorri (5) , S. Stolze (5) , B. Sulignano (1) , J. Uusitalo (5) , A. Ward (7) , M. Zielińska (1)

1 IRFU - Institut de Recherches sur les lois Fondamentales de l'Univers
2 GANIL - Grand Accélérateur National d'Ions Lourds
3 UNICAEN - Université de Caen Normandie
4 IPHC - Institut Pluridisciplinaire Hubert Curien
5 JYU - University of Jyväskylä
6 CSNSM - Centre de Sciences Nucléaires et de Sciences de la Matière
7 University of Liverpool

In the study of the odd-Z, even-N nuclei $^{243}$Es and $^{249}$Md, performed at the University of Jyväskylä, the fusion-evaporation reactions $^{197}$Au($^{48}$Ca,2n)$^{243}$Es and $^{203}$Tl($^{48}$Ca,2n)$^{249}$Md have been used for the first time. Fusion-evaporation residues were selected and detected using a gas-filled separator coupled with its focal-plane spectrometer. For $^{243}$Es, the recoil decay correlation analysis yielded a half-life of 24±3s and a maximum production cross section of 37±10nb. In the same way, a half-life of 26±1s, an α-branching ratio of 75±5%, and a maximum production cross section of 300±80nb were determined for $^{249}$Md. The decay properties of $^{245}$Es, the daughter of $^{249}$Md, were also measured: an α-branching ratio of 54±7% and a half-life of 65±6s. Experimental cross sections were compared to the results of calculations performed using the KEWPIE2 statistical fusion-evaporation code.

Keywords: Nuclear Reactions

Domains: Nuclear Experiment [nucl-ex]

R. Briselet, Ch. Theisen, M. Vandebrouck, A. Marchix, M. Airiau, et al.. Production cross section and decay study of $^{243}$Es and $^{249}$Md. Phys.Rev.C, 2019, 99 (2), pp.024614. ⟨10.1103/PhysRevC.99.024614⟩. ⟨hal-01897161⟩