Search results for "Electricity"
showing 10 items of 1225 documents
Development of a low-energy radioactive ion beam facility for the MARA separator
2016
A low-energy radioactive ion beam facility for the production and study of nuclei produced close to the proton drip line is under development at the Accelerator Laboratory of the University of Jyv\"askyl\"a, Finland. The facility will take advantage of the mass selectivity of the recently commissioned MARA vacuum-mode mass separator. The ions selected by MARA will be stopped and thermalised in a small-volume gas cell prior to extraction and further mass separation. The gas cell design allows for resonance laser ionisation/spectroscopy both in-gas-cell and in-gas-jet. The facility will include experimental setups allowing ion counting, mass measurement and decay spectroscopy.
Manufacturing an active X-ray mirror prototype in thin glass
2015
Adjustable mirrors equipped with piezo actuators are commonly used at synchrotron and free-electron laser (FEL) beamlines, in order to optimize their focusing properties and sometimes to shape the intensity distribution of the focal spot with the desired profile. Unlike them, X-ray mirrors for astronomy are much thinner in order to enable nesting and reduce the areal mass, and the application of piezo actuators acting normally to the surface appears much more difficult. There remains the possibility to correct the deformations using thin patches that exert a tangential strain on the rear side of the mirror: some research groups are already at work on this approach. The technique reported he…
Radiation-induced point defects in simple oxides
1998
We present a survey of recent theoretical studies of radiation-induced point defects in simple oxides with emphasis on highly ionic MgO, partly-covalent corundum (Al2O3) and ferroelectric KNbO3. The atomic and electronic structure of the electronic (F a and F centers) and hole centers, as well as interstitial atoms therein are discussed in light of the available experimental data. Results for defect diAusion and photo-stimulated F a fi F center conversion are also ana
Overview of the DEMO staged design approach in Europe
2019
This paper describes the status of the pre-conceptual design activities in Europe to advance the technical basis of the design of a DEMOnstration Fusion Power Plant (DEMO) to come in operation around the middle of this century with the main aims of demonstrating the production of few hundred MWs of net electricity, the feasibility of operation with a closed-tritium fuel cycle, and maintenance systems capable of achieving adequate plant availability. This is expected to benefit as much as possible from the ITER experience, in terms of design, licensing, and construction. Emphasis is on an integrated design approach, based on system engineering, which provides a clear path for urgent R&D …
High voltage conditioning of the electrostatic deflector of MARA
2016
Abstract MARA is a new recoil mass separator in the Accelerator Laboratory of University of Jyvaskyla (JYFL-ACCLAB) with a mass resolving power of 250 and an ion-optical configuration of QQQD E D M . In this paper the construction, control and conditioning of its electrostatic deflector are described. The deflector was designed for voltages up to 500 kV accross the gap, corresponding to a 3.6 MV/m field, to accomodate fusion reactions with inverse kinematics. Titanium electrodes with a beam dump opening in the anode are used. The conditioning procedure, which has been used repeatedly to take the deflector to 450 kV, is described, along with the safety systems and precautions that are in pla…
Upgrade and yields of the IGISOL facility
2008
The front end of the Jyvaskyla 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 Penn…
Decay spectroscopy of Pb97182179 and evidence for a 9/2− intruder state in Tl98181179
2017
The very neutron-deficient isobars Pb-179 and Tl-179 have been produced using the fusion-evaporation reactions Pd-104(Kr-78,xpyn), where x = 2. The gas-filled separator RITU was employed to transpo ...
Design of a second generation RFQ Ion Cooler and Buncher (RFQCB) for ISOLDE
2004
As a part of the ISOLDE Consolidation project, a new beam-cooling device will be incorporated into the High Resolution Separator (HRS) to improve the ion beam delivered to the experiments. The whole beam line at this point needs to be redesigned to accommodate the ion cooler and provide beam-matching. In this paper the status of the mechanical design, the optical design and the vacuum system of the device are presented.
Micellar versus hydro-organic mobile phases for retention-hydrophobicity relationship studies with ionizable diuretics and an anionic surfactant
2004
Abstract Logarithm of retention factors (log k ) of a group of 14 ionizable diuretics were correlated with the molecular (log P o/w ) and apparent (log P app ) octanol–water partition coefficients. The compounds were chromatographed using aqueous–organic (reversed-phase liquid chromatography, RPLC) and micellar–organic mobile phases (micellar liquid chromatography, MLC) with the anionic surfactant sodium dodecyl sulfate (SDS), in the pH range 3–7, and a conventional octadecylsilane column. Acetonitrile was used as the organic modifier in both modes. The quality of the correlations obtained for log P app at varying ionization degree confirms that this correction is required in the aqueou…
Improved primary regulation for minimum energy losses in islanded microgrids
2017
In this paper, an improved primary regulation is proposed for grid forming units supplying islanded microgrids. A minimum losses Optimal Power Flow is run off-line to devise the operating set points composing the primary regulation curve. In this way, after load perturbations, generators can reach an optimized operating point for a given and unique minimum losses energy flows distribution. The idea is to skip the hierarchical control architecture and provide a feasible and optimized operating point. A case study over 24 hours shows the effectiveness of this new approach as well as the improved operation quality of the system.