The heart of every ISOL (isotope separation on-line) facility is its target and ion source system. Its efficiency, selectivity and rapidity is decisive for the production of intense and pure ion beams of short-lived isotopes. Recent progress in ISOL target and ion source technology is discussed at the examples of radioactive ion beams of exotic zinc and tin isotopes that were purified by isothermal chromatography and molecular sideband separation respectively. An outlook is given to which other elements these purification methods are applicable.

The Advanced Time Delayed method has been used to measure the lifetimes of excited states in the exotic nuclei Sb-134, Sb-135 and Te-136 populated in the beta decay of Sn-134, Sn-135 and Sn-136, respectively. High purity Sn beams were extracted at the ISOLDE separator using a novel production technique utilizing the molecular SnS+ beams to isolate Sn from contaminating other fission products. Among the new results we have identified the 1/2(+) state in Sb-135 and its E2 transition to the lower-lying 5/2(+) state was found to be surprisingly collective. This measurement represents also one of the first applications of the LaBr3 scintillator to ultra fast timing.

The Advanced Time Delayed method has been used to measure the lifetimes of excited states in the exotic nuclei Sb-134, Sb-135 and Te-136 populated in the beta decay of Sn-134, Sn-135 and Sn-136, respectively. High purity Sn beams were extracted at the ISOLDE separator using a novel production technique utilizing the molecular SnS+ beams to isolate Sn from contaminating other fission products. Among the new results we have identified the 1/2(+) state in Sb-135 and its E2 transition to the lower-lying 5/2(+) state was found to be surprisingly collective. This measurement represents also one of the first applications of the LaBr3 scintillator to ultra fast timing.

The Advanced-Time-Delayed method was used to measure lifetimes of the states in Ar-41 populated in the beta decay of Cl-41. The nuclei Cl-41 were produced at ISOLDE by 1.4-GeV proton bombardment of a thick UCx target and mass-separated as molecular ions, XeCl+. Our measured half-life of the 167.1-keV state, T-1/2=315(15) ps, is significantly lower than the previously measured value of 410(30) ps. We have also determined T-1/2=260(80) ps and T-1/2 <= 46 ps for the 515.9- and 1867.7-keV states, respectively. These are the shortest lifetimes measured so far with the ultrafast timing method using the new LaBr3(Ce) crystals for gamma-ray detection.

In the framework of the EURISOL project, the production of neutron-rich isotopes of rubidium and cesium has been studied. The intensities of mass-separated beams of rubidium and cesium isotopes generated from a thick 238UCx target connected to a surface ionizer have been measured. The release properties of 140Cs and 91Rb have been investigated. The obtained results allowed us to determine the relative fission yields of rubidium and cesium isotopes with high accuracy.

The {beta} decay of {sup 135}Sn was studied at CERN/ISOLDE using a resonance ionization laser ion source and mass separator to achieve elemental and mass selectivity, respectively. {gamma}-ray singles and {gamma}-{gamma} coincidence spectra were collected as a function of time with the laser on and with the laser off. These data were used to establish the positions of new levels in {sup 135}Sb, including new low-spin states at 440 and 798 keV, which are given tentative spin and parity assignments of 3/2{sup +} and 9/2{sup +}, respectively. The observed levels of {sup 135}Sb are compared with shell-model calculations using different single-particle energies and different interactions.

J. Shergur,1,2 A. Wöhr,1,3 W. B. Walters,1 K.-L. Kratz,4 O. Arndt,4 B. A. Brown,5 J. Cederkall,6 I. Dillmann,4 L. M. Fraile,6,7 P. Hoff,8 A. Joinet,6 U. Köster,6 and B. Pfeiffer4 1Department of Chemistry, University of Maryland, College Park, Maryland 20742-2021, USA 2Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, USA 3Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556, USA 4Institut für Kernchemie, Universität Mainz, D-55128 Mainz, Germany 5Department of Physics and Astronomy and National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824-1321, USA 6ISOLDE, PH Department, CERN, CH-1211 Genève 23, Switzerland 7Departamento de Fı́sica Atómica Molecular y Nuclear, Universidad Complutense, E-28030 Madrid, Spain 8Department of Chemistry, University of Oslo, NO-1163 Oslo, Norway (Received 14 March 2005; published 12 August 2005)

The beta decay of Sn-135 was studied at CERN/ISOLDE using a resonance ionization laser ion source and mass separator to achieve elemental and mass selectivity, respectively. gamma-ray singles and gamma-gamma coincidence spectra were collected as a function of time with the laser on and with the laser off. These data were used to establish the positions of new levels in Sb-135, including new low-spin states at 440 and 798 keV, which are given tentative spin and parity assignments of 3/2(+) and 9/2(+), respectively. The observed levels of Sb-135 are compared with shell-model calculations using different single-particle energies and different interactions.

The level structure of odd-odd Sb-134 has been studied at CERN/ISOLDE following the beta(-) decay of Sn-134 and the beta-delayed neutron decay of Sn-135. Elemental and isobaric separation were accomplished by use of a resonance ionization laser ion source and an on-line mass separator, respectively. Both gamma-ray singles and gamma-gamma coincidence data were taken as a function of time. New levels at 279, 441, 555, 617, and 1385 keV have been identified and given proposed spin and parity assignments of 7(-), 5(-), 6(-), 4(-), and 5(-), respectively, following beta-delayed neutron decay of 7/2(-) Sn-135. New 1(-) levels have been identified at 1900, 2170, and 2430 keV following the beta(-) decay of 0(+) Sn-134. The resulting level structures are compared to shell-model calculations using the CD Bonn interaction and scaled and unscaled Kuo-Herling interactions developed for the Pb-208 region. Remarkably enough, the unscaled Kuo-Herling interaction provides the best fit for the levels below 1 MeV.

J. Shergur,1,2 A. Wöhr,1,3 W. B. Walters,1 K.-L. Kratz,4 O. Arndt,4 B. A. Brown,5 J. Cederkall,6 I. Dillmann,4 L. M. Fraile,6,7 P. Hoff,8 A. Joinet,6 U. Köster,6 and B. Pfeiffer4 1Department of Chemistry, University of Maryland, College Park, Maryland, 20742-2021, USA 2Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, USA 3Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556 4Institut für Kernchemie, Universität Mainz, D-55128 Mainz, Germany 5Department of Physics and Astronomy and National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824-1321, USA 6ISOLDE, PH Department, CERN, CH-1211 Genève 23, Switzerland 7Departamento de Fı́sica Atómica Molecular y Nuclear, Universidad Complutense, E-28030 Madrid, Spain 8Department of Chemistry, University of Oslo, NO-1163 Oslo, Norway (Received 21 December 2004; published 28 June 2005)

Radioactive ion beam intensities have been measured at ISOL (isotope separation on-line) facilities from many different targets, but only rarely these intensities are converted into production cross-sections. Here we discuss the method and possible problems in this conversion at the examples of Kr and Xe produced by 1.4 GeV-proton-induced fission of U-238 at ISOLDE and Rb and Cs produced by approximate to 10 MeV-neutron-induced fission of U-238 at PARRNe.

Production efficiencies of radioactive oxygen and nitrogen beams for the SPIRAL target-source system, measured at GANIL on the SIRa test bench, are presented. From the overall efficiency of oxygen, the product between the efficiency of transformation of O into CO and the effusion of CO from the target to the ion source, was deduced. The production yield measurements of oxygen and nitrogen isotopes performed on the SIRa test bench and those of fluorine directly measured on the SPIRAL facility are presented.

The energy dependence of production yields for Kr and Cs isotopes has been investigated with 600 MeV, 1 GeV and 1.4 GeV protons.

Several scientific committees, such as NUPECC [1], have established that neutron-rich beams will provide a wealth of new opportunities for nuclear physics studies. The proton-induced fission of actinide material is a proven mechanism for the production of neutron-rich nuclei, but, within the Eurisol project [2], new innovations are being tested with the goal of increasing current fission rates by three orders of magnitude.

Many elements are rapidly released from oxide matrices. Some oxide powder targets show a fast sintering, thus losing their favorable release characteristics. Loosely packed oxide fiber targets are less critical since they may maintain their open structure even when starting to fuse together at some contact points.The experience with various oxide fiber targets (titania, zirconia, ceria and thoria) used in the last years at ISOLDE is reviewed. For short-lived isotopes of Cu, Ga and Xe the zirconia and ceria targets respectively provided significantly higher yields than any other target (metal foils, oxide powders, etc.) tested before.Titania fibers, which were not commercially available, were produced in a relic process by impregnation of rayon felt in a titanium chloride solution and subsequent calcination by heating the dried felt in air. Thoria fibers were obtained either by the same process or by burning commercial gas lantern mantle cloth.In the future a beryllia fiber target could be used to produce very intense He-6 beams (order of 10(13) ions per second) via the Be-9(n,alpha) reaction using spallation neutrons. (C) 2003 Elsevier Science B.V. All rights reserved.

The PARRNe (Production d’Atomes Radioactifs Riches Neutrons) R&D program is dedicated to the determination of the best conditions for the production of neutron-rich beam in prospect of the SPIRAL2 project. A complete description of this program, its subdivisions (PARRNe 0, 1 and 2 sub-programs) and the different experimental setup involved can be found in [1,2]. An experiment using the “PARRNE 1” procedure aimed at measuring on-line production of rare gases was performed at CERN.