Eur. Phys. J. A 12, 309-316 (2001)

The decay chain revisited

A. Gizon¹, J. Genevey¹, C.F. Liang², P. Paris², D. Barnéoud¹, J. Inchaouh¹, I. Penev³ and A. Plochocki<sup>4

1</sup>  Institut des Sciences Nucléaires, IN2P3-CNRS/Université Joseph Fourier, F-38026 Grenoble Cedex, France
²  CSNSM, IN2P3-CNRS, Bt 104, F-91405 Campus-Orsay, France
³  Institute for Nuclear Research and Nuclear Energy, 1784 Sofia, Bulgaria
⁴  Institute of Experimental Physics, 00-681 Warsaw, Poland

genevey@isn.in2p3.fr

(Received: 20 August 2001 / Revised version: 22 October 2001 Communicated by D. Schwalm)

Abstract
An investigation of low-lying energy levels of ¹³⁰Pr and ¹³⁰Ce has been made via -decay. The radioactive parent nuclei were produced via ^94,96Mo + ⁴⁰Ca reactions at 6.8 MeV/nucleon and transported by a He-jet system. Gamma- -t, -X-t, -e ^--t coincidence measurements were performed. Internal conversion coefficients have been measured with a magnetic spectrometer. The new -decay half-life of ¹³⁰Nd has been determined to be 21(3) s. A partial level scheme of ¹³⁰Pr at low-spin has been constructed. The -decay of ¹³⁰Pr to ¹³⁰Ce suggests the existence of three -instable isomeric states in ¹³⁰Pr, while only one half-life T_1/2 = 40(4) s has been measured. Based on the present work and low-lying excited states in neighbouring odd-mass nuclei, the spins and parities of isomeric states in ¹³⁰Pr are proposed to be 2 ⁺, (4,5) ⁺ and (7,8 ). The ground state in ¹³⁰Pr is still undetermined.

PACS
23.20.Lv - Gamma transitions and level energies.
23.20.Nx - Internal conversion and extranuclear effects.
27.60.+j - .

© Società Italiana di Fisica, Springer-Verlag 2001