摘要:

The paper reports on experimental developments for studies of decays of proton radioactive nuclei on the Argonne Fragment Mass Analyzer. The results illustrate that there is a clear proton decay rate sensitivity to the unpaired neutron orbital in highly deformed odd‐odd nuclei consistent with the Influential Spectator Model of Ferreira and Maglione. No such sensitivity is observed for the proton decay rates of spherical odd‐odd nuclei studied here. The first ever study of proton decay from a nucleus,135Tb, produced via 1p6n fusion evaporation is also reported. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1615151

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

Two observations of fine structure in proton emission are reported : 3‐&mgr;s145Tm and 4‐ms141Ho. These experiments were performed using the Recoil Mass Separator (RMS) at the Holifield Radioactive Ion Beam Facility at Oak Ridge. The signals from the RMS detectors were digitally processed using Digital Gamma Finder modules. The fine structure branching ratios, 9.6±1.5&percent; and 0.70±0.15&percent;, and measured energies of the 2+excited levels in daughter nuclei, 330 and 202 keV, respectively, helped us to determine the deformations and wave functions of proton‐emitting states. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1615152

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

Since few years at the Legnaro National Laboratories we have recently started a program to study exotic decays at the proton drip‐line with particular attention to proton radioactivity in the rare earth region. In fact pemitting nuclei with 54 < Z < 64 are expected to be quite deformed in their ground state and their study is an important input for the theoretical models that describe this kind of decay. Our studies have brought, as first result, the discovery of the decay by pemission of117La where to p‐decaying levels have been found. Our experimental program continued with the study of the decay of126Pm. For this nucleus we can only conclude that our low statistics data show no evidence of p emission. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1615153

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

The gas‐filled recoil separatorrituhas been used to study neutron‐deficient nuclei above theN=82 neutron shell closure and beyond the proton drip line. New information about the proton emitting nuclei in Ir, Au and Tl isotopes was obtained including the identification of two new proton emitters. The systematics of low‐lying states in odd‐mass At isotopes beyond the proton drip line were studied down to191At using alpha‐decay. A new low‐lying state associated with an oblate &pgr;(2p− 1h) configuration was also observed in the corresponding Bi daughter nuclei. In order to realise these studies at the extreme limit of experimental devices, several technical developments at therituseparator were required. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1615154

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

The present status of prompt particle emission from high‐spin states in the massA∼ 60 region is shortly summarized. The focus lies on recent results from aGammasphereexperiment, which aimed at the combined in‐beam high‐resolution spectroscopy of light charged particles and &ggr; rays. More detailed studies of known cases as well as the identification of new cases of discrete prompt proton and &agr;‐particle emission from highly‐ and superdeformed states have been possible. Finally, future directions are briefly outlined. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1615155

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

We report on theoretical calculations in proton radioactivity that have been carried out over the past 2 years at Argonne National Laboratory. This includes calculations of decay rates for near‐spherical proton emitters based on particle‐vibration coupling [1], fine structure in the proton decay of141Ho [2], and recent work on the effect of triaxiality on the decay rate of a deformed proton emitter. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1615156

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

Proton radioactivity from deformed nuclei is usually well reproduced using the particle‐rotor model in the strong coupling limit. Recent attempts to go beyond the adiabatic approximation, by the addition of the Coriolis interaction, have failed in reproducing the experimental results. We show that the introduction of the pairing residual interaction in the non‐adiabatic coupled channel method permits to recover the perfect agreement with data. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1615157

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

Models for deformed proton emitters are reviewed. The non‐adiabatic coupled‐channel framework with rotational coupling and the adiabatic Nilsson‐orbit model are discussed and compared. An improvement of the adiabatic approach is obtained by taking care of the diagonal part of the Coriolis coupling. For the description of the proton radioactivity of141Ho, we investigate the role of &ggr;‐vibrational excitations in the daughter nucleus140Dy. It is shown that the coupling to triaxial degrees of freedom strongly influences theoretical predictions. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1615158

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

The generalization of the unified theory of proton decay on the basis of methods of unified theory nucleus and the open Fermi‐systems theory has been done taking into account the reconstruction of the proton‐emitting nucleus frame in the proton decay process. The new integral formulae based on the methods of projection operators and orthogonal projecting for the proton partial width amplitudes have been constructed. These formulae have been used for the analysis of proton widths for case of even‐odd spherical proton‐emitting nuclei. It has been shown that the deviations of correct proton widths taking into account the differences between shell‐model proton energies and proton separation energies from proton widths calculated on the basis of well‐depth procedure are small. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1615159

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

Fine structure and proton decay widths of odd‐A spherical proton emitters has been described [1] taking into account the vibrational excitations of the daughter nucleus. In the present work, we show that, if the residual pairing interaction is also included, two phonon states are required in order to reproduce the experimental results. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1615160

出版商:AIP    

年代:1903

数据来源: AIP