MADMAX Cryogenic Stability: Preliminary Design of the Macumba Demo-Coil for Physics

International audienceThe objective of the MADMAX project, led by the Max Planck Institute, is to detect axion dark matter with a mass of ∼100 µeV. To amplify the detection signal of the photons, induced by the axion conversion, the MADMAX dipole must produce ∼9 T within a 1.35 m aperture where a booster, the signal amplifier, is located. At the current stage of the project a demonstrator, Macumba, is needed for various reasons, i) to show that nominal current operation can be reached with MADMAX, ii) to practice coil fabrication, iii) to train the team that will be in charge of the MADMAX operation at DESY and iv) to start learning about the axion physics. Here is presented the design of the Macumba demonstrator magnet that targets operating conditions close to the final magnet in terms of loadline, mechanical constraints and heat generation. The structure and conductor of the demonstrator must be similar to a MADMAX coil to face the same fabrication issue as for MADMAX coils. This would allow improving the manufacturing procedures and tooling. In addition, Macumba magnet produces a physic-compatible magnetic field in an aperture able to host an R&D booster in preparation for the operation at DESY

Geographical analysis for the integration of a microalgae production and biorefining unit in "Pays de la Loire"

International audienceMicroalgae are photosynthetic species able to transform carbon dioxide, for example from combustion processes, into biomass and valuable molecules (lipids, proteins, antioxidants, polysaccharides etc.). The team “Marine bioprocesses and separations” of GEPEA laboratory has been developing an integrated approach to valorise microalgae, from the culture to the biorefinery, for several years. A new collaboration was build with geographers (LETG-Nantes) to explore the French geographic areas where an industrial microalgae production and biorefining unit could be built. A database on the scale of metropolitan France was realized including the parameters for the culture of microalgae (light, water, carbon dioxide, nitrogen, phosphorus, heat, available lands). Three sizes of production unit were taken into account to identify potential zones of installation. Maps were then produced to compare the most interesting sites. This first work was followed by a second, to study more details on the coast of Pays de la Loire. Besides the choice of the site, new criteria were added: regulatory requirements in the installation, perception of the project by local actors (local authorities, public, neighbourhood) that must be known to prepare a local integration

Geographical analysis for the integration of a microalgae production and biorefining unit in "Pays de la Loire"

International audienceMicroalgae are photosynthetic species able to transform carbon dioxide, for example from combustion processes, into biomass and valuable molecules (lipids, proteins, antioxidants, polysaccharides etc.). The team “Marine bioprocesses and separations” of GEPEA laboratory has been developing an integrated approach to valorise microalgae, from the culture to the biorefinery, for several years. A new collaboration was build with geographers (LETG-Nantes) to explore the French geographic areas where an industrial microalgae production and biorefining unit could be built. A database on the scale of metropolitan France was realized including the parameters for the culture of microalgae (light, water, carbon dioxide, nitrogen, phosphorus, heat, available lands). Three sizes of production unit were taken into account to identify potential zones of installation. Maps were then produced to compare the most interesting sites. This first work was followed by a second, to study more details on the coast of Pays de la Loire. Besides the choice of the site, new criteria were added: regulatory requirements in the installation, perception of the project by local actors (local authorities, public, neighbourhood) that must be known to prepare a local integration

Development, Integration, and Test of the MACQU Demo Coil Toward MADMAX Quench Analysis

The MADMAX project aims at detecting axion dark matter in the mass range of 100 μeV. To facilitate axion to photon conversion with detectable rate a superconducting dipole magnet with a large bore is needed. The MADMAX dipole magnet has to generate ~9 T in a 1.35 m aperture over ~1.3 m in length. A key challenge for a magnet made of a cable in-conduit conductor (CICC), operating at 1.8 K with an indirect bath cooling is the quench detection. In order to validate feasibility, a mock-up coil with a quench behavior scalable to MADMAX was designed and produced. This mock-up was used to benchmark numerical simulations of the quench in the THEA code. The paper gives an overview of the technicaldetails of the MACQU test coil. The conductor, the magnet, the busbar and the supporting and cryogenic systems were designed at CEA. The cable was manufactured in China at the Chang Tong INC from WST Nb-Ti strands, the insertion and compaction was achieved in the ASIPP institute with a copper profile from Aurubis. The winding of the coil and the busbar pre-forming were performed at Bilfinger Noell as well as the assembly of the supporting structure and the thermal shield. The magnet was integrated in the JT60 test station at CEA Saclay and extensively tested