Biomedical subjects

B Herskind

Publications and source records attributed to B Herskind.

At least 19 recordsLinked to original sources

PubMed2004

Compound and rotational damping in warm deformed rare-earth nuclei.

The gamma decay in the quasicontinuum from selected configurations of the rotational nucleus 163Er has been measured with the EUROBALL array. A new analysis technique has allowed for the first time to directly measure the compound and rotational damping widths Gamma (micro) and Gamma (rot). Values of Gamma (micro) approximately 20 keV and Gamma (rot) approximately 200 keV are obtained in the spin region I approximately 30-40 variant Planck's over 2pi, in good agreement with microscopic cranked shell model calculations. A dependence of Gamma (micro) and Gamma (rot) on the K-quantum number of the nuclear states is also presented.

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PubMed2002

Octupole vibration in superdeformed 152(66)Dy86.

Nine transitions of dipole character have been identified linking an excited superdeformed (SD) band in 152Dy to the yrast SD band. As a result, the excitation energy of the lowest level in the excited SD band has been measured to be 14 238 keV. This corresponds to a 1.3 MeV excitation above the SD ground state. The levels in this band have tentatively been determined to be of negative parity and odd spin. The measured properties are consistent with an interpretation in terms of a rotational band built on a collective octupole vibration.

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PubMed2002

Evidence for second-phonon nuclear wobbling.

The nucleus 163Lu has been populated through the reaction 139La(29Si,5n) with a beam energy of 157 MeV. Three triaxial, strongly deformed (TSD) bands have been observed with very similar rotational properties. The first excited TSD band has earlier been assigned as a one-phonon wobbling excitation built on the lowest-lying (yrast) TSD band. The large B(E2)(out)/B(E2)(in) value obtainable for one of four observed transitions between the second and first excited TSD bands is in good agreement with particle-rotor calculations for a two-phonon wobbling excitation.

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PubMed2002

(68)(28)Ni(40): Magicity versus superfluidity.

The neutron-rich (66,68)Ni have been produced at GANIL via interactions of a 65.9A MeV 70Zn beam with a 58Ni target. Their reduced transition probability B(E2;0(+)(1)-->2+) has been measured for the first time by Coulomb excitation in a (208)Pb target at intermediate energy. The B(E2) value for (68)Ni(40) is unexpectedly small. An analysis in terms of large scale shell model calculations stresses the importance of proton core excitations to reproduce the B(E2) values and indicates the erosion of the N = 40 harmonic-oscillator subshell by neutron-pair scattering.

Journal Article↗

PubMed2002

Direct decay from the superdeformed band to the yrast line in 15266Dy86.

The excitation energy, spin, and parity of the yrast superdeformed band in 152Dy have been firmly established. The evidence comes mainly from the measured properties of a 4011 keV single-step transition connecting the yrast superdeformed level fed by the 693 keV transition to the 27- yrast state. Four additional, weaker, linking gamma rays have been placed as well. The excitation energy of the lowest superdeformed band member is 10 644 keV and its spin and parity are determined to be 24+.

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PubMed2001

Evidence for the wobbling mode in nuclei.

The nucleus (163)Lu has been populated through the fusion-evaporation reaction (139)La((29)Si,5n)(163)Lu with a beam energy of 152 MeV. The electromagnetic properties of several connecting transitions between two presumably triaxial, strongly deformed (TSD) bands have been studied. Evidence is presented for the assignment of the excited TSD band as a wobbling mode built on the yrast TSD band, based on comparisons to new calculations in which an aligned particle is coupled to a strongly deformed triaxial rotor. The wobbling mode is uniquely related to triaxiality in nuclei.

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PubMed1996