Publications: Conference

Author(s) :R. Luis (ITN), Y. Romanets (ITN), J.C. David (CEA), D. Ene (CEA), I. F. Goncalves (ITN), Y. Kadi (CERN), C. Kharoua (CERN), F. Negoita (NIPNE), R. Rocca (CERN), L. Tecchio (INFN), P. Vaz (ITN)

One of the EURISOL-DS (The EURopean Isotope Separation On-Line Radioactive Ion Beam – Design Study) objectives is to provide a safe and reliable facility layout meeting the following operational parameters: 1. 4 MW proton beam of 1 GeV impinging on the Hg converter 2. High neutron source (~3x1016 neutrons/s ) generated by spallation reactions 3. Fission rate on a fissile target (235U) above 1015 fissions/s In this work, the state-of-the-art Monte Carlo codes MCNPX and FLUKA were used to assess the neutronics performance of the target station but also provide estimations of dose rate and activation for assessing the safety conditions prevailing in the facility. This work aimed to identify the facility regions and components (systems) which may need to be improved or even redesigned. For this purpose, an analysis of the activities and associated dose rates of each of the elements (cladding, cooling systems, cables etc.) of the converter and of the fission targets was carried out, during operation and after shutdown, for diverse cooling times. The results obtained from the safety and radioprotection studies show high activation values in some areas that will require the adjustment of the composition of some materials. Such specific conditions for the operation and maintenance of the facility may require an increase of the complexity of some supply systems. (NEUDOS-11)

Author(s) :R. Luis (ITN), Y. Romanets (ITN), J. Bermudez (INFN) , J.C. David (CEA), D. Ene (CEA), I. F. Goncalves (ITN), Y. Kadi (CERN), C. Kharoua (CERN), F. Negoita (NIPNE), R. Rocca (CERN), L. Tecchio (INFN), P. Vaz (ITN)

The EURISOL (The EURopean Isotope Separation On-Line Radioactive Ion Beam) project aims at producing high intensity radioactive ion beams produced by neutron-induced fission on fissile targets (235U) surrounding a liquid mercury converter. A proton beam of 1GeV and 4MW impinges on the converter, generating, by spallation reactions, high neutron fluxes that induce fission in the surrounding fissile targets. In this work the state-of-the-art Monte Carlo codes MCNPX and FLUKA were used to assess the neutronics performance of the system, which geometry, inspired in the MAFF concept, allows a versatile manipulation of the fission targets. The first objective of the study was to optimize the geometry and the materials used in the fuel and reflector elements of the system, in order to achieve the highest possible fission rates. Indeed, it is shown that the appropriate combination of fission target material and surrounding reflector material leads to the aimed value of 1015 fissions/s per fission target. The second part of this work is related to safety parameters. Dose rate and activation calculations were carried out in order to identify the necessary shielding and access restrictions for each section of the entire facility, including maintenance, storage and remote control spaces. The results presented in this work indicate that there are good prospects for the feasibility of the EURISOL fission target, in its new configuration, considered in this work. The safety analysis indicates that some points of the facility need special attention from the safety and radioprotection points of view. (ICENES'09)

Author(s) :H.Zimmermann, A.Bechtold,D.Habs, P.Kolb, A.Schempp

The IH-type RFQ for the MAFF project at the LMU Munich is integrated into a test bench at the IAP in Frankfurt. There are two IH-RFQ existing, the MAFF IHRFQ and the HIS at GSI. The parameters of the MAFF IH-RFQ are very similar to a 4-rod type machine, the REX-ISOLDE RFQ at CERN. So the results can be compared directly. Experimental results will be presented.

Author(s) :A. Bechtold, D. Habs, LMU, Munich, Germany. J. Fischbach, U. Ratzinger, J. Rehberg, M. Reichwein, A. Schempp, IAP, Frankfurt, O. Kester, GSI, Darmstadt, Germany. J. Häuser, NTG, Gelnhausen, Germany.

The IH-type RFQ for the MAFF project at the LMU in Munich is presently under construction and will be integrated into a beam test stand at the IAP in Frankfurt. It is second RFQ following the IH resonator concept and the first one that can be directly compared to a very similar 4-rod type machine, namely the REX-ISOLDE RFQ at CERN.

Author(s) :D. Ene, J-C. David, D. Doré, D. Ridikas

HIAT is an international conference dealing with heavy ion accelerators and their components, including their design, realization, test and operation.

Author(s) :A. Facco, A. Balabin, R. Paparella, D. Zenere, INFN-Laboratori Nazionali di Legnaro, Padova, Italy; D. Berkovits, J. Rodnizki, SOREQ, Yavne, Israel; J. L. Biarrotte, S. Bousson, A. Ponton, IPN Orsay, France; R. Duperrier, D. Uriot, CEA/Saclay, France; V. Zvyagintsev, TRIUMF, Vancouver, Canada

A 1 GeV, 5 mA cw superconducting proton/H- linac, with the capability of supplying cw primary beam to up to four targets simultaneously by means of a new beam splitting scheme, is under study in the framework of the EURISOL DS project which aims to produce an engineering-oriented design of a next generation European Radioactive beam facility. The EURISOL driver accelerator would be able to accelerate also a 100 μA, 3He beam up to 2.2 GeV, and a 5 mA deuteron beam up to 264 MeV. The linac characteristics and the status of the beam dynamics studies will be presented.

Author(s) :P.A.Posocco, M.Comunian, A.Palmieri, A.Pisent

In the framework of EURISOL design study*, the superconducting solution for the Post-Accelerator injector foresees the use of two RFQs, one Super Conducting and one Normal Conducting, both operating CW at 88 MHz. After the multiple ionization in the ECR breeder on low voltage platform, the rare ions beam (3 ≤ A/q ≤ 7) is bunched at the main frequency by the NC RFQ without both losses and transverse emittance increase and accelerated afterwards through the SC RFQ up to 560 keV/u. A 8.8 MHz pulsed beam can be delivered to experiments placing a 3 harmonic buncher before the NC RFQ with overall beam losses lower than 25%. The beam dynamics results of the study of this solution as well as the main RF design and construction analysis of the main components are presented.

Author(s) :Gwenal Le Dem, Marco Di Giacomo

The Eurisol heavy ion post-accelerator and the Spiral2 deuton/ion MEBT should transport a continuous wave (cw) beam from respectively a 88.05 MHz RFQ (β respectively 0.036 and 0.04) to a drift-tube linac. A high frequency chopper is being studied to select only 1 bunch over N, 10 < N < 10000 as asked by the physicists. It requires pulses higher than 3 kV, rising in less than 7 ns at a repetition rate up to 8.8 MHz. These figures are at the border of what can be provided by the travelling wave fast choppers and the capacitive-type chopping technologies. We have reviewed the current fast and slow chopping structures and their associated pulse generator. Some preliminary RF simulations to adapt the present chopping devices to our requirements are presented. The main limitations of these technologies when applied to isolate bunches in ion cw accelerators are also shown. Our first studies and results to solve the arising problems are discussed.

Author(s) :A. Bechtold, LMU, Munich, Germany. A. Schempp, IAP, Frankfurt, Germany.

A combination of three superconducting RFQs has been proposed for the EURISOL post accelerator layout. At least one of this triplet could be replaced by a normal conducting continuous wave (c.w.) device. A preliminary Electrode and cavity design has been studied.

Author(s) :Y. Blumenfeld on behalf of the EURISOL Design Study

Abstract of invited talk at Franco-Japanese Symposium: New Paradigms in Nuclear Physics. Paris, France, Sept.29 - Oct.2, 2008