Studies of Fragment Angular Distributions in the Fission ofBi209andU238

Fragment angular distributions from fission of238U,209Bi and197Au by 140-MeV4He Ions

“…2. These are in good agreement with the trends of lower energy work [10][11][12]. In Table 1 the values for the laboratory and center-of-mass anisotropies are listed along with the corresponding transformation parameters.…”

“…Thus, it would appear that the results of Ref. 10, which led to the suggestion of a possible transition in the saddle point deformation from the second maximum to the liquid drop barrier, may be more an artifact of the reaction mechanism than of the fission process itself. The present work suggests that in order to extract meaningful ~eff values for fissioning systems-which would be very desirable, especially at low xj.…”

“…However, the present status of the data does not warrant such a correction. Transmission coefficients T~ were calculated using the deformed optical model potential of Rasmussen and Sugawara-Tanabe [17], with parameters derived from fitting the experimental excitation function for 23sU fission [10,14,18]. The parameters were: well-depth, V 0 = 130 MeV; radius parameter, r o = 1.194 F; and diffuseness, d=0.35F.…”

Alpha Particle Induced Fission of 209Bi at 55.7 and 58.6 MeV

“…Umezawa et al [4] have given a prescription for the calculation of the most probable charge (Zp) for the actinides. Though this method is not suitable for pre-actinides and as no other empirical analysis or data exits for pre-actinides, it was used to calculate the Zp values (Table 3).…”

Nuclear chemistry progress report. [Summary of research at the University of Maryland]

“…The comparisons in Table I demonstrate The agreement between the various types of data in Table I in predicting the gross features of the target-projectile interaction suggests that the interaction radius concept can be generalized for use in predicting total reaction cross sections and maximum angular momenta for 20 Ne and 16 0 reactions with heavy elements. From the relationship ( 1) where v~z 1 z 2 e 2 /R and E is the center-of-mas energy of the projectile, cm an excellent fit to the experimental total reaction cross section data for 20 Ne and 16 0 bombardments of uranium above 120 MeV and 100 MeV, respectively, is obtained if one simply sets R=R. t=l2.75 fm in for 20 Ne and 12.60 fm for 16 0, as determined from the Fresnel scattering analysis.…”