New studies and a short review of heavy neutron-rich transfer products
H. M. Devaraja, S. Heinz, D. Ackermann, T Göbel, F. P. Heßberger, S. Hofmann, J. Maurer, G. Münzenberg, A. G. Popeko, A. V. Yeremin
Abstract
Abstract We present new results on multi-nucleon transfer reactions in low-energy collisions of $$^{48}\hbox {Ca}+{}^{238}\hbox {U}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msup> <mml:mrow/> <mml:mn>48</mml:mn> </mml:msup> <mml:mtext>Ca</mml:mtext> <mml:mo>+</mml:mo> <mml:msup> <mml:mrow/> <mml:mn>238</mml:mn> </mml:msup> <mml:mtext>U</mml:mtext> </mml:mrow> </mml:math> measured at the velocity filter SHIP of GSI Helmholtz Centre, where we observed around 90 different nuclides from Tl to Am ( $$Z=$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>Z</mml:mi> <mml:mo>=</mml:mo> </mml:mrow> </mml:math> 81–95). We followed the idea to use uranium targets for the synthesis of neutron-rich MNT products, particularly in the region below lead, which was triggered by model calculations. The $$\gamma $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>γ</mml:mi> </mml:math> , $$\alpha $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>α</mml:mi> </mml:math> and spontaneous fission activities of the populated nuclides have been analyzed for their identification. The cross-sections of the observed isotopes for elements $$Z = $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>Z</mml:mi> <mml:mo>=</mml:mo> </mml:mrow> </mml:math> 81–93 as a function of their mass number have been investigated. Excitation energy, total kinetic energy and the influence of nuclear shell effects on the production cross-sections of the observed transfer products have been studied. Also we present a compact review and comparative analysis of various multi-nucleon transfer and fragmentation reactions which are aimed at the synthesis of neutron-rich nuclides along the $$N=126$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>N</mml:mi> <mml:mo>=</mml:mo> <mml:mn>126</mml:mn> </mml:mrow> </mml:math> shell closure in heavy nuclei.