Small cross section of the synthesis of darmstadtium in the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mmultiscripts><mml:mi>Ca</mml:mi><mml:mprescripts/><mml:none/><mml:mn>48</mml:mn></mml:mmultiscripts><mml:mo>+</mml:mo><mml:mmultiscripts><mml:mi>Th</mml:mi><mml:mprescripts/><mml:none/><mml:mn>232</mml:mn></mml:mmultiscripts></mml:mrow></mml:math> reaction
Annotatsiya
The smallness of the cross section of evaporation residues formed in the hot fusion reaction <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mrow><a:mmultiscripts><a:mi>Ca</a:mi><a:mprescripts/><a:none/><a:mn>48</a:mn></a:mmultiscripts><a:mo>+</a:mo><a:mmultiscripts><a:mi>Th</a:mi><a:mprescripts/><a:none/><a:mn>232</a:mn></a:mmultiscripts></a:mrow></a:math> is analyzed by the dinuclear system model (DNS). The capture probability has been calculated by solving the dynamical equations of motion for the relative distance between the centers of mass of the DNS nuclei. Fusion of nuclei is considered as evolution of the DNS to a stable compound nucleus. The fusion probability has a bell-like shape and quasifission is one of reasons causing smallness of the yield of the evaporation residues products. Another reason is the decrease of the fission barrier for the isotopes <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:mmultiscripts><b:mi>Dm</b:mi><b:mprescripts/><b:none/><b:mrow><b:mn>275</b:mn><b:mtext>–</b:mtext><b:mn>285</b:mn></b:mrow></b:mmultiscripts></b:math> related with the shell effects in the neutron structure. The agreement of the theoretical results obtained for the yield of the evaporation residues with the experimental data measured in the Factory of Superheavy Elements of Joint Institute for Nuclear Research is well. Published by the American Physical Society 2024