摘要:

Laser spectroscopy measurements have been carried out on very neutron-deficient platinum isotopes with the COMPLIS experimental set-up on line with the ISOLDE-Booster facility. For the first time, Hg &agr;-decay was exploited to extend the very light platinum chain. Using the5d96s&hthinsp;3D3→5d96p&hthinsp;3P2optical transition, hyperfine spectra of182,181,180,179,178Ptand183Ptmwere recorded for the first time. The variation of the mean square charge radius between these nuclei, the magnetic moments of the odd isotopes and the quadrupole moment of183Ptmwere thus measured. A large deformation change between183Ptgand183Ptm,an odd-even staggering of the charge radius and a deformation drop fromA=179are clearly observed. All these results are discussed and compared with microscopic theoretical predictions using Hartree-Fock-Bogolyubov calculations using the Gogny force. ©1998 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.57390

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

The interaction cross-sections(&sgr;I)of light radioactive nuclei close to the neutron drip line(17,19B,&hthinsp;14Be)have been measured at around 800AMeV. The effective mean-square-matter radii of these nuclei have been deduced from&sgr;Iby a Glauber-type calculation. A large increase in the radius from15Bto17Bhas been observed. A similar rate of increase is seen in17Bto19Band in12Beto14Be.Questions concerning the neutron halo structure in17,19Bare discussed. ©1998 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.57311

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

The masses of 48 neutron-rich nuclei extending from55Scto75Cuhave been determined from the final set of data to be acquired with the time-of-flight-isochronous (TOFI) spectrometer. The masses of eight isotopes (68Fe,70,71Co,73Ni,and72–75Cu) are reported for the first time. The resulting masses now tie in neatly with the masses of previously measured neutron-rich Zn and Ga isotopes determined from fission product &bgr;-endpoint measurements. A careful evaluation of the calibration sensitivity is made with respect to inclusion or exclusion of these heavy known species and excellent calibration stability is found. Contrasting these results with previous TOFI measurements, we find that these new results fall between the results of Tu &etal; (1) which trend to slightly less bound masses as one proceeds to the most neutron-rich species and Seifert &etal; (2) which shows the opposite trend. Good agreement with the predictions of several mass models and Audi-Wapstra systematics are found. ©1998 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.57312

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

A high-efficient method for measuring isotope shifts and hyperfine structures in optical transitions of radioactive atoms is presented. The method is based on application of laser resonance ionization in the mass-separator ion source. The sensitivity of the method is determined by a high efficiency of the laser ion source and low background of the detection system, making use of counting &agr;-particles following the decay of the isotope under investigation. The possibilities of this method are shown in the experiment with155Yband154Tm(I=9).The isotope shifts and electromagnetic moments have been measured. ©1998 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.57313

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

A procedure based on the regularity property of the mass surface is proposed to make predictions for the masses of neutron rich deformed nuclei in the rare earth region. Tables are given for the estimated masses; they extend up to the presumed limit of the deformation region. ©1998 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.57304

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

Beta-ray end-point energies for the decay of150Erand151Erwere measured using a plastic scintillator—Ge,&bgr;+−&ggr;coincidence spectrometer. Mass excess values are reported for these nuclides and for members of the &agr;-decay chain which terminates at151Er.Our results are compared with extrapolations based on systematic properties for other nuclei. ©1998 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.57204

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

The ground-state nuclear densities and radii of208Pbdoubly-magic nucleus have been evaluated within the framework of the relativistic mean-field approach. It is pointed out that the neutron density and the neutron radius in the RMF approach are quite different from both, the empirical data and the predictions of the Skyrme-Hartree-Fock model. ©1998 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.57205

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

Recently the CERN/ISOLDE laser ion source was optimized to provide intense beryllium ion beams. This allowed us to perform optical spectroscopy on7,9,10Beyielding the unknown magnetic moment of7Beand the isotope shifts in the lithium-like spectrum ofBe+.Furthermore we measured the magnetic moment of the neutron halo nucleus11Bevia &bgr;-NMR on optically polarized nuclei. ©1998 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.57392

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

Nuclear shapes and masses are estimated by a new method. The main feature of this method lies in estimating shell energies of deformed nuclei from spherical shell energies by mixing them with appropriate weights. The spherical shell energies are calculated from single-particle potentials, and, till now, two mass formulas have been constructed from two different sets of potential parameters. The standard deviation of the calculated masses from all the experimental masses of the 1995 Mass Evaluation is about 760 keV. Contrary to the mass formula by Tachibana, Uno, Yamada and Yamada in the 1987–1988 Atomic Mass Predictions, the present formulas can give nuclear shapes and predict on super-heavy elements. ©1998 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.57206

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

The interaction radii of proton-rich, radioactive31Ga, 32Ge, 33As, 34Se, 35Brisotopes were measured using the direct method. The secondary beams were produced using a78Krprimary beam of 73 MeV/nucleon in conjunction with SISSI and the SPEG spectrometers at GANIL. Most elements show reduced radii which vary with N, with a minimum aroundN=36–38.The experimental reduced radii are compared to theoretical values obtained from Glauber reaction cross-section calculations based on Relativistic Mean Field (RMF) nuclear densities. ©1998 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.57314

出版商:AIP    

年代:1998

数据来源: AIP