De la CAO aux calculs par éléments finis

28 pages, 17 figures - ACCThe main objective of this work was to creat an interface between the design tool for CAO: Catia and a numerical computation code Cast3m. This work is motivated by the conception of one new type of superconducting cavity: triple Spoke cavity. This cavity is proposed to accelerate the protons beam, in the low beta section, as part of the europeen project HIPPI. Some multiphysical problems should be studied for the design of this cavities, it involves 3D simulation. One of the useful numerical code is Cast3m, but its 3D modeling remains time consomming. The essential work presented in this report is to establish a programm CASàCAO, which allows the use of the finite elements meshing made by Catia in Cast3m calculation. The concept of this interface is original, since as usual the interface concerns only the drawing between Catia and a commercial mechanical code. The advantage of this work is at first the time saving in stage of the modeling. More, the developed programm CASàCAO could mafe a reorganization of the meshing according to optimize the calculations. This developed interface CAOàCAS is applicated successfully to the concept of the triple spoke cavities for HIPPI projet, some results are shown in this report

Simulations for mechanical design of nozzle for extrude of windowless solid hydrogen cryogenic target.

International audienceThe solid hydrogen target is proposed for studies of exotic nuclei beams of Spiral projects. In this paper, the simulations works in order to study mechanical behaviours of hydrogen solid at cryogenic temperature are presented. The no linear mechanical calculations with contact behaviours are carried out

SPL 704 MHz beta 0.65 cavities mechanical design for EUCARD.

International audienceThe optimizations, based on electromechanical simulations have been carried out in order the design 704 Mhz 5-cell elliptic superconducting cavity for the intermediate energy section (beta 0.65) for accelerating high intensity proton beams in pulsed mode

Mechanical Design of Triple Spoke cavity for Eurisol

International audienceWithin the framework of EURISOL programme, supported by European Union, IPN Orsay has proposed a 352 MHz triple Spoke superconducting cavity for the intermediate energy section beta 0.3 of high power proton linear accelerator. Triple Spoke cavity has a complicate geometry, 3D modeling with coupled electromagnetic and mechanic calculations were performed

Etudes de la stabilité mécanique des cavités supraconductrices et de la méthode de rigidification par projection thermique de cuivre

La recherche en physique nécessite aujourd'hui des accélérateurs de hautes énergie ou de forte intensité; l'utilisation des cavités supraconductrices constitue un progrés technologique trés important : elles permettent de fournir de hauts gradients accélérateurs avec une dissipation négligeable. Un des problèmes fondamentaux dans la conception de ces cavités est la variation de fréquence due aux forces de Lorentz : ayant un facteur de qualité beaucoup plus élevé que le facteur de couplage externe externe lié à la charge du faisceau, ces cavités ont des bandes passantes trés étoites, les faibles déformations des parois sous l'effet des forces de Lorentz peuvent engendrer une variation de fréquence supérieure à la bande passante lorsque le gradient accélérateur devient trés élevé, ce qui constitue une source d'instabilité. La contribution de cette thèse consiste d'abord en une analyse numérique de ce problème, puis en une étude mécanique d'une nouvelle méthode de rigidification...Today's researche in nuclear physics and in particle physics needs high energy or high intensity accelerators; the use of superconducting cavities constitutes a very important technological advance for the design of such facilities, allowing high accelerating gradient with few dissipation. One of the major problems is the frequency shift under Lorentz forces : since the quality factor of the superconducting cavities is much higher than the external factor depending on the beam charge, their bandwidths are very narrow (several Hertz). Even very small mechanical deformations under Lorentz forces could induce a frequency shift which exceeeds the bandwidth when the accelerating gradient becomes very high. The contribution of this thesis consists at first in a numerical analysis of this problem, then in a mechanical study of a new method for stiffening superconducting cavities : a copper coating over their external surface by thermal spray techniques.ORSAY-PARIS 11-BU Sciences (914712101) / SudocSudocFranceF