Identification of the New Isotope \u3csup\u3e244\u3c/sup\u3eMd

In an experiment performed at Lawrence Berkeley National Laboratory\u27s 88-inch cyclotron, the isotope Md244 was produced in the Bi209(Ar40,5n) reaction. Decay properties of Md244 were measured at the focal plane of the Berkeley Gas-filled Separator, and the mass number assignment of A=244 was confirmed with the apparatus for the identification of nuclide A. The isotope Md244 is reported to have one, possibly two, α-decaying states with α energies of 8.66(2) and 8.31(2) MeV and half-lives of 0.4-0.1+0.4 and ∼6 s, respectively. Additionally, first evidence of the α decay of Bk236 was observed and is reported

Decay and Fission Hindrance of Two- and Four-Quasiparticle K Isomers in (254)Rf

Two isomers decaying by electromagnetic transitions with half-lives of 4.7(1.1) and 247(73)μs have been discovered in the heavy Rf254 nucleus. The observation of the shorter-lived isomer was made possible by a novel application of a digital data acquisition system. The isomers were interpreted as the Kπ=8-, ν2(7/2+[624],9/2-[734]) two-quasineutron and the Kπ=16+, 8-ν2(7/2+[624],9/2-[734])⊗ - 8-π2(7/2-[514],9/2+[624]) four-quasiparticle configurations, respectively. Surprisingly, the lifetime of the two-quasiparticle isomer is more than 4 orders of magnitude shorter than what has been observed for analogous isomers in the lighter N=150 isotones. The four-quasiparticle isomer is longer lived than the Rf254 ground state that decays exclusively by spontaneous fission with a half-life of 23.2(1.1)μs. The absence of sizable fission branches from either of the isomers implies unprecedented fission hindrance relative to the ground state

Decay and Fission Hindrance of Two- and Four-Quasiparticle K Isomers in Rf 254

Two isomers decaying by electromagnetic transitions with half-lives of 4.7(1.1) and 247(73)μs have been discovered in the heavy Rf254 nucleus. The observation of the shorter-lived isomer was made possible by a novel application of a digital data acquisition system. The isomers were interpreted as the Kπ=8-, ν2(7/2+[624],9/2-[734]) two-quasineutron and the Kπ=16+, 8-ν2(7/2+[624],9/2-[734])⊗ - 8-π2(7/2-[514],9/2+[624]) four-quasiparticle configurations, respectively. Surprisingly, the lifetime of the two-quasiparticle isomer is more than 4 orders of magnitude shorter than what has been observed for analogous isomers in the lighter N=150 isotones. The four-quasiparticle isomer is longer lived than the Rf254 ground state that decays exclusively by spontaneous fission with a half-life of 23.2(1.1)μs. The absence of sizable fission branches from either of the isomers implies unprecedented fission hindrance relative to the ground state

Identification of the New Isotope 244Md

In an experiment performed at Lawrence Berkeley National Laboratory’s 88-inch cyclotron, the isotope 244Md was produced in the 209Bi(40Ar,5n) reaction. Decay properties of 244Md were measured at the focal plane of the Berkeley Gas-filled Separator, and the mass number assignment of A = 244 was confirmed with the apparatus for the identification of nuclide A. The isotope 244Md is reported to have one, possibly two, α-decaying states with α energies of 8.66(2) and 8.31(2) MeV and half-lives of 0.4+0.4-0.1 and ∼6 s, respectively. Additionally, first evidence of the α decay of 236Bk was observed and is reported

Decay and Fission Hindrance of Two- and Four-Quasiparticle K

Two isomers decaying by electromagnetic transitions with half-lives of 4.7(1.1) and 247(73)μs have been discovered in the heavy Rf254 nucleus. The observation of the shorter-lived isomer was made possible by a novel application of a digital data acquisition system. The isomers were interpreted as the Kπ=8-, ν2(7/2+[624],9/2-[734]) two-quasineutron and the Kπ=16+, 8-ν2(7/2+[624],9/2-[734])⊗ - 8-π2(7/2-[514],9/2+[624]) four-quasiparticle configurations, respectively. Surprisingly, the lifetime of the two-quasiparticle isomer is more than 4 orders of magnitude shorter than what has been observed for analogous isomers in the lighter N=150 isotones. The four-quasiparticle isomer is longer lived than the Rf254 ground state that decays exclusively by spontaneous fission with a half-life of 23.2(1.1)μs. The absence of sizable fission branches from either of the isomers implies unprecedented fission hindrance relative to the ground state

Decay and Fission Hindrance of Two- and Four-Quasiparticle K Isomers in (254)Rf

International audienceTwo isomers decaying by electromagnetic transitions with half-lives of 4.7(1.1) and 247(73) mu s have been discovered in the heavy (254)Rf nucleus. The observation of the shorter-lived isomer was made possible by a novel application of a digital data acquisition system. The isomers were interpreted as the K-pi = 8(-), nu(2)(7/2(+)[624]; 9/2(-)[734]) two-quasineutron and the K-pi = 16(+), 8(-)nu(2)(7/2(+)[624]; 9/2(-)[734] circle times 8(-)pi(2) (7/2(-)[514]; 9/2(+)[624]) four-quasiparticle configurations, respectively. Surprisingly, the lifetime of the two-quasiparticle isomer is more than 4 orders of magnitude shorter than what has been observed for analogous isomers in the lighter N = 150 isotones. The four-quasiparticle isomer is longer lived than the (254)Rf ground state that decays exclusively by spontaneous fission with a half-life of 23.2(1.1) mu s. The absence of sizable fission branches from either of the isomers implies unprecedented fission hindrance relative to the ground state

Decay and Fission Hindrance of Two- and Four-Quasiparticle K Isomers in ^{254}Rf.

Two isomers decaying by electromagnetic transitions with half-lives of 4.7(1.1) and 247(73) μs have been discovered in the heavy ^{254}Rf nucleus. The observation of the shorter-lived isomer was made possible by a novel application of a digital data acquisition system. The isomers were interpreted as the K^{π}=8^{-}, ν^{2}(7/2^{+}[624],9/2^{-}[734]) two-quasineutron and the K^{π}=16^{+}, 8^{-}ν^{2}(7/2^{+}[624],9/2^{-}[734])⊗8^{-}π^{2}(7/2^{-}[514],9/2^{+}[624]) four-quasiparticle configurations, respectively. Surprisingly, the lifetime of the two-quasiparticle isomer is more than 4 orders of magnitude shorter than what has been observed for analogous isomers in the lighter N=150 isotones. The four-quasiparticle isomer is longer lived than the ^{254}Rf ground state that decays exclusively by spontaneous fission with a half-life of 23.2(1.1) μs. The absence of sizable fission branches from either of the isomers implies unprecedented fission hindrance relative to the ground state

Decay and Fission Hindrance of Two- and Four-Quasiparticle K Isomers in 254Rf

Two isomers decaying by electromagnetic transitions with half-lives of 4.7(1.1) and 247ð73Þ μs have been discovered in the heavy 254Rf nucleus. The observation of the shorter-lived isomer was made possible by a novel application of a digital data acquisition system. The isomers were interpreted as the Kπ ¼ 8−, ν2ð7=2þ½624; 9=2−½734Þ two-quasineutron and the Kπ ¼ 16þ, 8−ν2ð7=2þ½624; 9=2−½734Þ ⊗ 8−π2ð7=2−½514; 9=2þ½624Þ four-quasiparticle configurations, respectively. Surprisingly, the lifetime of the two-quasiparticle isomer is more than 4 orders of magnitude shorter than what has been observed for analogous isomers in the lighter N ¼ 150 isotones. The four-quasiparticle isomer is longer lived than the 254Rf ground state that decays exclusively by spontaneous fission with a half-life of 23.2ð1.1Þ μs. The absence of sizable fission branches from either of the isomers implies unprecedented fission hindrance relative to the ground state.peerReviewe