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219Rn recoils from the alpha decay of 223Ra have been used to study the efficiency and delay time distributions of a gas-catcher/ion guide system. Ions with charge states up to +4 were coming out of the gas cell. Combining efficiency and delay time measurements, ion survival times in plasma free conditions can be deduced. [Copyright &y& Elsevier]

Abstract: The laser ion source at the IGISOL facility, Jyväskylä, has been used to study the effects of the passage of a primary beam through an ion guide via the dynamic time profiles of yttrium and related molecular compounds. The accessibility of a neutral fraction for laser ionization is shown to be restricted to the nozzle region in the presence of a weak plasma. The survival of this neutral fraction cannot be explained by recombination of the buffer gas alone and perhaps indicates a suppression of the transport of ions due to a plasma-generated electric field. The concept of a competition between the processes that create and destroy the ion of interest is used to explain the different trends in the ratio of yttrium to yttrium oxide following the extraction of a stopped primary beam of 89Y21+ in both helium and argon buffer gases. [Copyright &y& Elsevier]

Abstract: The laser ion source project at the IGISOL facility, Jyväskylä, has motivated the development and construction of an rf sextupole ion beam guide (SPIG) to replace the original skimmer electrode. The SPIG has been tested both off-line and on-line in proton-induced fission, light-ion and heavy-ion induced fusion–evaporation reactions and, in each case, has been directly compared to the skimmer system. For both fission and light-ion induced fusion, the SPIG has improved the mass-separated ion yields by a factor of typically 4–8. Correspondingly, the transmission efficiency of both systems has been studied in simulations with and without space charge effects. The transport capacity of the SPIG has been experimentally determined to be ∼1012 ionss−1 before space charge effects start to take effect. A direct comparison with the simulation has been made using data obtained via light-ion fusion evaporation. Both experiment and simulation show an encouraging agreement as a function of current extracted from the ion guide. [Copyright &y& Elsevier]

Abstract: The front end of the Jyväskylä IGISOL facility was upgraded in 2003 by increasing its pumping capacity and by improving the radiation shielding. In late 2005, the skimmer electrode of the mass separator was replaced by a sextupole ion guide, which improved the mass separator efficiency up to an order of magnitude. The current design of the facility is described. The updated yield data, achieved with and without the additional JYFLTRAP purification, using both fusion evaporation reactions and particle induced fission is presented to give an overview of the capability of the facility. These data have been determined either by radioactivity measurements or by direct ion counting after the Penning trap system. [Copyright &y& Elsevier]

Abstract: A laser ion source is under development at the IGISOL facility, Jyväskylä, in order to address deficiencies in the ion guide technique. The key elements of interest are those of a refractory nature, whose isotopes and isomers are widely studied using both laser spectroscopic and high precision mass measurement techniques. Yttrium has been the first element of choice for the new laser ion source. In this work, we present a new coupled dye–Ti:Sapphire laser scheme and give a detailed discussion of the results obtained from laser ionization of yttrium atoms produced in an ion guide via resistive heating of a filament. The importance of not only gas purity, but indeed the baseline vacuum pressure in the environment outside the ion guide is discussed in light of the fast gas phase chemistry seen in the yttrium system. A single laser shot model is introduced and is compared to the experimental data in order to extract the level of impurities within the gas cell. [Copyright &y& Elsevier]

This article reports on recent on-line yield measurements employing the light-ion and heavy-ion reaction-based ion guide systems and new results on α-recoil ion transport properties in ion guides with and without electric fields. In addition, the presently used ion guide designs for fusion evaporation reactions are introduced. The present study investigated different schemes for ion extraction from the gas cell. The addition of an extra ring electrode between the traditional skimmer electrode and the exit hole led to transmission independent of the primary beam intensity as opposed to strong intensity dependence observed earlier with the plain skimmer only. Furthermore, the mass resolving power of the IGISOL mass separator was increased to 1100 as compared to 250 with the skimmer system when using the RF-sextupole for the extraction from the heavy-ion ion guide. As a new method, the possibility to increase the ion guide efficiency by injecting electrons into the stopping volume is introduced. The efficiency of the electron emitter ion guide was a factor of ten higher in off-line conditions. Also, the influence of the buffer gas purity on the ion survival is discussed. [Copyright &y& Elsevier]