Cryogenic Design of the 43 T LNCMI Grenoble Hybrid Magnet

AbstractThe association of two inner resistive coils (Polyhelix and Bitter) producing 34.5 T with an outer NbTi superconducting coil producing 8.5 T to obtain a 43 T hybrid magnet is a technical challenge. Accidental failure modes leading to complex electromagnetic behaviors and large transient dynamical forces should be anticipated. These considerations lead to a reinforced design and a thermo-hydraulic strategy to limit the overpressure. The cryostat has been designed with innovative thermo-mechanical supports sustaining the coil at 1.8 K-1200 hPa and the eddy current shield at 30 K, both being possibly overloaded by high dynamic forces in the worst accidental failure case

High frequency ECR ion source (60 GHz) in pre-glow mode for bunching of beta-beam isotopes

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Split magnet for efficient electron cyclotron resonance ion sources developments

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Measurement of the Sixty GHz ECR Ion Source using Megawatt magnets - SEISM magnetic field map

International audienceLPSC has developed a 60 GHz Electron Cyclotron Resonance (ECR) Ion Source prototype called SEISM. The magnetic structure uses resistive polyhelix coils designed in collaboration with the French National High Magnetic Fields Facility (LNCMI) to produce a CUSP magnetic configuration. A dedicated test bench and appropriate electrical and water cooling environments were built to study the validity of the mechanics, the thermal behaviour and magnetic field characteristics obtained at various current intensities. During the last months, measurements were performed for several magnetic configurations, with up to 7000 A applied on the injection and extraction coils sets. The magnetic field achieved at 13000 A is expected to allow 28 GHz ECR condition, so by extrapolation 60 GHz should be possible at about 28000 A. However, cavitation issues that appeared around 7000 A are to be solved before carrying on with the tests. This contribution will recall some of the crucial steps in the prototype fabrication, and show preliminary results from the measurements at 7000 A. Possible explanations for the differences observed between the results and the simulation will be given

A Reduced Basis Framework: Application to large scale non-linear multi-physics problems

In this paper we present applications of the reduced basis method (RBM) to large-scale non-linear multi-physics problems. We first describe the mathematical framework in place and in particular the Empirical Interpolation Method (EIM) to recover an affine decomposition and then we propose an implementation using the open-source library Feel++ which provides both the reduced basis and finite element layers. Large scale numerical examples are shown and are connected to real industrial applications arising from the High Field Resistive Magnets development at the Laboratoire National des Champs Magnétiques Intenses

A 60 GHz electron cyclotron resonance ion source for pulsed radioactive ion beam production

TUCO-A03International audienceElectron Cyclotron Resonance Ion Sources (ECRIS) are very efficient to produce continuous and pulsed ion beams. The ECRIS scaling laws show that the plasma density increases as the square of the microwave frequency. Consequently, the efficiency, the average charge of the ionic charge state distribution and the extracted currents increase as well. LPSC is developing a 60 GHz pulsed ion source prototype. In order to have efficient ionization, the ion source volume has to be small, and due to the frequency value, the magnetic field has to be high (6 T at the injection, 3 T at the extraction, a closed surface with |B| = 2.1 T and a magnetic mirror of 4 T). The generation of the high magnetic field requires the use of helix techniques developed at GHMFL. As a first approach, a cusp structure has been chosen. 2D and 3D simulations were used to define the geometry of the helixes. Calculus has shown that it is necessary to use 2 groups of 2 coaxial helixes. An aluminum helix prototype has been machined to test at low current density the accuracy of the calculations. The axial magnetic field of the prototype was measured and results are in very good agreement with the numerical values

A 60 GHz electron cyclotron resonance ion source for pulsed radioactive ion beam production

TUCO-A03International audienceElectron Cyclotron Resonance Ion Sources (ECRIS) are very efficient to produce continuous and pulsed ion beams. The ECRIS scaling laws show that the plasma density increases as the square of the microwave frequency. Consequently, the efficiency, the average charge of the ionic charge state distribution and the extracted currents increase as well. LPSC is developing a 60 GHz pulsed ion source prototype. In order to have efficient ionization, the ion source volume has to be small, and due to the frequency value, the magnetic field has to be high (6 T at the injection, 3 T at the extraction, a closed surface with |B| = 2.1 T and a magnetic mirror of 4 T). The generation of the high magnetic field requires the use of helix techniques developed at GHMFL. As a first approach, a cusp structure has been chosen. 2D and 3D simulations were used to define the geometry of the helixes. Calculus has shown that it is necessary to use 2 groups of 2 coaxial helixes. An aluminum helix prototype has been machined to test at low current density the accuracy of the calculations. The axial magnetic field of the prototype was measured and results are in very good agreement with the numerical values

SEISM : a 60GHz cusp electron cyclotron resonance ion source

Conference Proceedings can be submitted to Review of Scientific InstrumentsInternational audienceThe LPSC is involved for several years in a challenging R&D effort dedicated to study the production of pulsed radioactive ions beams with high ionization efficiency. The driving force of these studies is the long term Beta Beam scenario study. The ins and outs of the Beta Beams source requirements will be recalled. The generation of the high magnetic field requires the use of helix techniques developed at LNCMI. As a first approach, a cusp structure has been chosen. 3D simulations were used to define the geometry of the helices. The CAD mechanical design of the magnetic structure has been performed at LPSC and was optimized to decrease the total volume of the source. The first 60 GHz magnetic structure (helices coils in their tanks, electrical and water cooling environment) should be available before the end of 200