Description of α-decay of heavy and superheavy nuclei A. Sobiczewski and A. Parkhomenko Sołtan Institute for Nuclear Studies, Warsaw XII Nuclear Physics Workshop Kazimierz Dolny, Sept , 2005 Program 1. Introduction 2. Description of Q α 3. Formula for T α 4. Description of T α 5. Conclusions

NucleiN MeV rms MeV e-e o-e e-o o-o Table 1 Z = N = (201 nuclei)

Phenomenological formula for T α log 10 T α (Z,N) = a Z (Q α - E) -1/2 + b Z + c a = b = c =

Nuclein rmsnp e-e o-e e-o o-o Table 2 Z = N = (201 nuclei)

Nuclein rmsnp e-e o-e e-o o-o Table 3 Z = N = (201 nuclei)

5. Conclusions 1) Macro-micro calculations describe Q α of heaviest nuclei with an average accuracy of about 200 keV (e-e nuclei) to 300 keV (o-o nuclei). 2) With a simple (5-parameter) phenomenological formula, one can reasonably desribe T α of heavy and superheavy nuclei (within approximately a factor of 1.3, 2, 3 and 4 for e-e, o-e, e-o and o-o, respectively). 3) To the total inaccuracy of calculated T α, the inaccuracy Q α contributes importantly. Due to this, the above factor increases to about 5, 12, 11 and 17, respectively, i.e. by about a factor of 4 to 5. 4) Effects of shell structure of nuclei on T α are large and well seen in its systematics, for both deformed and spherical nuclei.