Search results for "ION SOURCES"
showing 10 items of 61 documents
Hydrogen plasma induced photoelectron emission from low work function cesium covered metal surfaces
2017
Experimental results of hydrogen plasma induced photoelectron emission from cesium covered metal surfaces under ion source relevant conditions are reported. The transient photoelectron current during the Cs deposition process is measured from Mo, Al, Cu, Ta, Y, Ni, and stainless steel (SAE 304) surfaces. The photoelectron emission is 2–3.5 times higher at optimal Cs layer thickness in comparison to the clean substrate material. Emission from the thick layer of Cs is found to be 60%–80% lower than the emission from clean substrates. peerReviewed
Cyclotron instability in the afterglow mode of minimum-B ECRIS.
2016
It was shown recently that cyclotron instability in non-equilibrium plasma of a minimum-B electron cyclotron resonance ion source (ECRIS) causes perturbation of the extracted ion current and generation of strong bursts of bremsstrahlung emission, which limit the performance of the ion source. The present work is devoted to the dynamic regimes of plasma instability in ECRIS operated in pulsed mode. Instability develops in decaying plasma shortly after heating microwaves are switched off and manifests itself in the form of powerful pulses of electromagnetic emission associated with precipitation of high energy electrons. Time-resolved measurements of microwave emission bursts are presented. I…
Ion source research and development at University of Jyväskylä: Studies of different plasma processes and towards the higher beam intensities
2015
MonPS16; International audience; The long-term operation of high charge state electron cyclotron resonance ion sources fed withhigh microwave power has caused damage to the plasma chamber wall in several laboratories.Porosity, or a small hole, can be progressively created in the wall on a year time scale, which cancause a water leak from the cooling system into the plasma chamber vacuum. A burnout of theVENUS chamber is investigated. Information on the hole formation and on the necessary localhot electron power density is presented. Next, the hot electron flux to the wall is studied bymeans of simulations. First, the results of a simple model assuming that electrons are fullymagnetized and …
Estimating ion confinement times from beam current transients in conventional and charge breeder ECRIS
2019
International audience; Cumulative ion confinement times are probed by measuring decaying ion current transients in pulsed material injection mode. The method is applied in a charge breeder and conventional ECRIS yielding mutually corroborative results. The cumulative confinement time estimates vary from approximately 2 ms–60 ms with a clear dependence on the ion charge-to-mass ratio—higher charges having longer residence times. The long cumulative confinement times are proposed as a partial explanation to recently observed unexpectedly high ion temperatures. The results are relevant for rare ion beam (RIB) production as the confinement time and the lifetime of stable isotopes can be used f…
Human fascioliasis infection sources, their diversity, incidence factors, analytical methods and prevention measures
2018
AbstractHuman fascioliasis infection sources are analysed for the first time in front of the new worldwide scenario of this disease. These infection sources include foods, water and combinations of both. Ingestion of freshwater wild plants is the main source, with watercress and secondarily other vegetables involved. The problem of vegetables sold in uncontrolled urban markets is discussed. Distinction between infection sources by freshwater cultivated plants, terrestrial wild plants, and terrestrial cultivated plants is made. The risks by traditional local dishes made from sylvatic plants and raw liver ingestion are considered. Drinking of contaminated water, beverages and juices, ingestio…
New exotic beams from the SPIRAL 1 upgrade
2018
Since 2001, the SPIRAL 1 facility has been one of the pioneering facilities in ISOL techniques for reaccelerating radioactive ion beams: the fragmentation of the heavy ion beams of GANIL on graphite targets and subsequent ionization in the Nanogan ECR ion source has permitted to deliver beams of gaseous elements (He, N, O, F, Ne, Ar, Kr) to numerous experiments. Thanks to the CIME cyclotron, energies up to 20 AMeV could be obtained. In 2014, the facility was stopped to undertake a major upgrade, with the aim to extend the production capabilities of SPIRAL 1 to a number of new elements. This upgrade, which is presently under commissioning, consists in the integration of an ECR booster in the…
Information sources used for vacation tourists in tourist destinations
2012
En esta investigación se analiza el uso de las fuentes de información y su incidencia en distintas etapas del proceso de decisión, incidiendo en la búsqueda de información realizada por los turistas en destino. Los resultados muestran que tanto el número y tipo de fuentes de información utilizadas, así como la intensidad de la búsqueda y las decisiones tomadas en destino, es muy diferente del que realizan los turistas antes de llegar a su destino vacacional. Basados en los resultados, como parte de las conclusiones, se exponen ciertas directrices de interés para la gestión empresarial, en relación a la utilización de fuentes de información en los destinos turísticos. This research examines …
Interaction risk with proton pump inhibitors in general practice: significant disagreement between different drug-related information sources.
2006
Aims To compare information on drug–drug interactions (DDIs) reported on two standard drug-related information sources (Summary of Product Characteristics and Drugdex system by Micromedex), by assessing the prevalence and predictors of potential DDI with proton pump inhibitors (PPIs) in general practice. Methods From the ‘Caserta-1’ Local Health-Service database, 156 general practitioners (GPs) were recruited. From more than 180 000 individuals registered on their lists, we selected patients receiving co-prescription of PPI and medications at interaction risk, according to the Italian Summary of Product Characteristics (SPC) of PPI and Drugdex information, during the year 2003. Thereafter, …
Information sources used for vacation tourists in tourist destinations
2012
En esta investigación se analiza el uso de las fuentes de información y su incidencia en distintas etapas del proceso de decisión, incidiendo en la búsqueda de información realizada por los turistas en destino. Los resultados muestran que tanto el número y tipo de fuentes de información utilizadas, así como la intensidad de la búsqueda y las decisiones tomadas en destino, es muy diferente del que realizan los turistas antes de llegar a su destino vacacional. Basados en los resultados, como parte de las conclusiones, se exponen ciertas directrices de interés para la gestión empresarial, en relación a la utilización de fuentes de información en los destinos turísticos. This research examines …
Visibilidad y usabilidad de la literatura profesional en DoIS (Documents in Information Science)
2004
The fundamental aspect born with the generalization of information networks has been the phenomenon of the tooinformation, the availability of a great number of resources means that the people, whom deposit their documents in the network, establish appropriate mechanisms so the information is accessible and recovered. Over the last years in Library and Information Science, several LIS professionals work in DoIS, Documents in Information Science. The DoIS team has been working the visibility and usability of the site, to fulfill the objective to spread the service within the community of librarians and archivists.