Proton instability of 73Rb

The study of the stability of an astrophysically interesting nucleus ⁷³Rb was performed by searching its β⁺ and proton decay at the ISOLDE facility at CERN. Light rubidium isotopes were produced in a spallation reaction of a niobium target induced by a pulsed 1 GeV proton beam. The previously reported proton-unbound character of ⁷³Rb was confirmed and the upper limit for its production cross-section was reduced by more than one order of magnitude.     

Baryon pairs production ine + e − annihilation at\sqrt s = 2.4 GeV

Search for baryon pairs production ine ⁺ e ^? annihilation at \(\sqrt s = 2386 MeV\) is reported. The data relate to a luminosity of 161 nb^?1 collected by the DM2 experiment at DCI, the Orsay colliding ring. First measurements of directe ⁺ e ^? annihilation into \(\Lambda \bar \Lambda \) and ofe ⁺ e ^?→ \(p\bar p\) at this energy are presented. First observation of a goode ⁺ e ^?→ \(n\bar n\) candidate is reported and upper limits are given fore ⁺ e ^?→ \(n\bar n, \Lambda \bar \sum ^0 + c.c.\) and \(\Sigma ^0 \bar \Sigma ^0 \) .     

Ozone decomposition in concentrated aqueous solutions of salts

Effect of high concentrations of electrolytes (Na₂SO₄, NaCl, and NaNO₃) on the rate of ozone decomposition in water was studied. The conversion kinetics of O₃ dissolved in these solutions was analyzed. The rate constants of ozone decomposition were determined.     

Interplay between single-particle and collective effects in the odd-A Cu isotopes beyond N=40

Collective properties of the low-lying levels in the odd-A 67-73Cu were investigated by Coulomb excitation with radioactive beams. The beams were produced at ISOLDE and postaccelerated by REX-ISOLDE up to 2.99 MeV/u. In 67,69Cu, low-lying 1/2(-), 5/2(-), and 7/2(-) states were populated. In 71,73Cu, besides the known transitions deexciting the single-particle-like 5/2(-) and core-coupled 7/2(-) levels, gamma rays of 454 and 135 keV, respectively, were observed for the first time. Based on a reanalysis of beta-decay work and comparison with the systematics, a spin 1/2(-) is suggested for these excited states. Three B(E2) values were determined in each of the four isotopes. The results indicate a significant change in the structure of the odd-A Cu isotopes beyond N=40 where single-particle-like and collective levels are suggested to coexist at very low excitation energies.     

Isomer separation and measurement of nuclear moments with the ISOLDE RILIS

Short-lived radioisotopes are element selectively ionized by the resonance ionization laser ion source (RILIS) of the on-line isotope separator ISOLDE (CERN). The relative production of low and high spin isomers can be significantly changed when a narrow-bandwidth laser is used to scan through the atomic hyperfine structure. This allows the assignment of gamma ray transitions to the decay of the individual isomers. Moreover, the measurement of the hyperfine splitting provides a very sensitive method for the determination of magnetic moments of exotic isotopes. The technical developments are discussed for the example of copper. This revised version was published online in August 2006 with corrections to the Cover Date.     

Nuclear temperatures obtained from light-charged-particle yields in low-energy ternary fission

Nuclear temperatures were determined from yields of isotopes with 1 ?Z? 14 accompanying the spontaneous and neutron-induced fission of heavy elements. The mean temperature derived from the corresponding temperature distributions amounts to 1.10±0.15 MeV. Received: 10 August 2001 / Accepted: 5 October 2001     

Nuclear structure of 189Tl states studied via \beta^{{+}}_{} /EC decay and laser spectroscopy of 189m+gPb

The /EC decay of ^{189m, g}Pb has been studied at the ISOLDE facility using nuclear spectroscopy and in-source laser spectroscopy. A level scheme of ¹⁸⁹Tl has been built from - coincidence relationships and information on the feeding of some excited levels of ¹⁸⁹Tl provided by the hyperfine spectra obtained from laser ionization. The half-lives of both the 13/2⁺ and 3/2^{- 189}Pb isomers have been estimated to be T _1/2 = 50±3 s and T _1/2 = 39±8 s, respectively. Calculations have been performed for different oblate and prolate nuclear deformations using an axial-rotor coupled to one-quasiparticle model, a structure has been suggested for the low-lying levels of the ¹⁸⁹Tl nucleus.     

Laser spectroscopy measurements of neutron-rich tellurium isotopes by COMPLIS

Laser spectroscopy based on resonant ionization of laser-desorbed atoms has been used to study the neutron-rich tellurium isotopes with the COMPLIS facility at ISOLDE-CERN. Isotope shifts and hyperfine structures of several neutron-rich Te isotopes: ^120?136Te and ^{123 m?133 m}Te have been measured. From the hyperfine structure we have extracted magnetic and quadrupole moments. Changes in the mean square charge radii have been deduced and their comparison with the known data for the other elements near Z?=?50 is presented. The experimental δ?<?r ²> values are compared with those obtained from relativistic mean field calculations.