Superheavy research in Japan

Extraction of probability of compound-nucleus formation

“…The experimental data of evaporation cross sections are taken from refs. [11][12][13][14][15] methods of deducing P CN give similar results for "cold" fusion reactions.…”

“…Fig.1 shows the deduced mean values of logarithm of P CN (which gives the order of magnitude of P CN ) as a function the charge number of the compound nucleus. The squares denote the results with the "cold" fusion, i.e., the reactions with Pb and Bi targets [11,12,15]. The open circles denote the results with the "hot" fusion, i.e., the reactions with 48 Ca bombarding on actinite targets [13,14].…”

Synthesis and Study of Superheavy Elements

“…Comparing properties of "light" isotopes, produced in "cold" fusion reactions [9,11], with those of "heavy" ones, produced in Act. + 48 Ca reactions (Table II), one can see, that addition of several neutrons leads to a signifi- cant increase in lifetimes (Table III).…”

“…Figure 2 shows the production cross-sections of transfermium nuclei in "hot" and "cold" fusion reactions. During 2003-2008, the RIKEN group (Japan) performed an experiment to synthesize element 113 in a 209 Bi+ 70 Zn reaction using the gas-filled separator GARIS [11]. The beam-on-target time amounted 7477 h and total accumulated dose of 70 Zn projectiles was 8.48 •10 19 .…”

Study of alpha-decay half-lives with deformed, oriented daughter nuclei

“…On the one hand, a lot of superheavy elements or isotopes have been produced by the cold-, warm-and hot fusion reaction methods. [14][15][16] By detecting the alpha-radioactivity, many newly synthesized superheavy nuclei have been successfully identified. On the other hand, one has observed the alpha-radioactivities for some light neutrondeficient isotopes, such as [105][106][107][108][109][110] Te, 17-21 110-113 I, 17 109-113 Xe, 17,18,21 114 Ba 22 and so forth.…”