[en] The bandhead energies for the two-particle states in the doubly odd actinide nucleus 2 ₉₅⁴⁶Am₁₅₁ are calculated involving single particle states up to a summed energy (E/sub p/+E/sub n/) up to 300 keV based on an evaluation of the zero range residual interaction energy contribution. The results are compared with the available experimental data. It is concluded that the ground state is the high spin isomer with K/sup π/ = 7^- corresponding to the configuration ](5/2)⁺[642]/sub p/:(9/2) ^-[734]/sub n/] with the K/sup π/ = 2^- of the same configuration as the low spin isomer at an excitation energy of (30 +- 10) keV. The K/sup π/ = 2⁺ ](5/2)^-[523]/sub p/:(9/2) ^-[734]/sub n/] bandhead is predicted to lie at about the same energy as the K/sup π/ = 2^- state. Predictions are made in all regarding the expected location of twelve two-particle states (six Gallagher-Moszkowski pairs)

[en] Semiconductor gamma-spectrometry has been used to identify ²⁴⁶Pu, ²⁴⁷Pu, sup(246m)Am and ²⁴⁷Am in plutonium targets irradiated in the central channel of the high-flux SM-2 reactor. The half-lives of ²⁴⁶PU, ²⁴⁷Pu, sup(246m)Am and ²⁴⁷Am are found to be: for ²⁴⁶PU=10.78+-0.5 days, ²⁴⁷Pu=2.27+-0.23 days, sup(246m)Am--24.7+-0.7 min, and ²⁴⁷Am=23.0+-1.3 min. The effective cross section of ²⁴⁶Pu burnup, according to Westcott for the central channel of the SM-2 reactor is calculated to be 7000+-3000 b

[en] The method of semiconductor γ spectrometry was used to identify ²⁴⁶Pu, ²⁴⁷Pu, /sup 246m/Am, and ²⁴⁷Am in plutonium targets irradiated in the central channel of a high-flux SM-2 reactor. The results of a determination of the half-lives of ²⁴⁶Pu, ²⁴⁷Pu, /sup 246m/Am, and ²⁴⁷Am are cited. The values found are: 10.78 +/- 0.05 days for ²⁴⁶Pu, 2.27 +/- 0.23 days for ²⁴⁷Pu, 24.7 +/- 0.7 min for /sup 246m/Am, and 23.0 +/- 1.3 min for ²⁴⁷Am. The effective cross-section of burnout of ²⁴⁶Pu was calculated according to Westcott for the central channel of the SM-2 reactor and is 7000 +/- 3000 barns

[en] Intense sources of ²⁴⁶Pu have been produced (through double neutron capture by ²⁴⁴Pu) for making detailed electromagnetic and conversion-electron measurements of the decay of ²⁴⁶Am/subm/ to levels of ²⁴⁶Cm. γ rays from ²⁴⁶Pu decaying to ²⁴⁶Am levels were identified in a chemical milking experiment. Of the 260 ²⁴⁶Cm γ rays observed, 97 are new and 64 have been assigned multipolarities from Si (Li) conversion-electron measurements. Some transitions were found to have strong E0 components, and two pure E0 transitions were observed. High-resolution γ-γ--time coincidence measurements were used to establish 54 levels, from which the low-energy band structure of ²⁴⁶Cm was determined. The investigation confirmed previous assignments of K/sup pi/=0^-, 1^-, and 2^- octupole bands, and a K/sup pi/=0⁺ band at 1175 keV. We have also identified the probable K/sup pi/=3^- octupole band, and a second K/sup pi/=0⁺ band at 1289 keV. The two K/sup pi/=0⁺ bands are discussed in terms of possible collective excitations. Other identified bands are discussed in terms of two-quasiparticle and multipole-phonon excitations

[en] Neutron-rich actinide nuclei were searched, for which relatively large rates of β^--delayed fission are expected, so that they are suitable for experimental investigation of fission barriers. (orig.)

[en] A procedure is outlined for predicting the bandhead energies of the two-particle (intrinsic) states of odd-odd deformed nuclei based on a quantitative evaluation of the zero range n-p residual interaction energy. We present our results for 250Bk, where many such levels are experimentally known, and for 236Np and 246Am, where the information is very scarce and that too uncertain, to illustrate the effectiveness of this approach

[en] The evaluators present in this publication spectroscopic data and level schemes from radioactive decay and nuclear reaction studies for all nuclei with mass number A=246.

[en] The role of the band quantum number K in influencing the character of allowed β transitions in heavy deformed nuclei is examined. The conditions for the occurrence of K-forbidden decays in this region are explored. Specific cases of ''allowed'' β decays proceeding via ΔK=2 to ΔK=6 channels are presented to illustrate the phenomenon. The listed ΔK=2 transitions, which by themselves contribute over 10% of all the presently known allowed transitions for A≥228 nuclei, are seen to have an average log ft≥9.0, which is clearly outside the normal range for allowed transitions. It is concluded that, wherever the β-connected states can be confidently labelled using the I^πK quantum numbers, the K-forbiddenness is in general as significant as that involving the other two (spin and parity) quantum numbers. (orig.)

[en] Importance of knowledge of trustworthy nuclear characteristics of transplutonium elements is noted from the point of view of increased demands of science and technology. Data on determination of americium 241, 243, 245, 246, 247; curium 245, 246; berkelium 249; californium 249 and einsteinium 253 half-life periods are presented along with the data on partial period of berkelium 249 alpha decay and ratio of alpha and beta decay probability

[en] Short note