| Paper | Title | Page |
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| TUP085 | Study of NbTi Welded Parts | 659 |
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| Due to its properties, niobium-titanium alloy is widely used to manufacture the flanges of superconducting niobium accelerating cavities. The material hardness is compliant to provide UHV-tight connections with aluminum gaskets or spring-type gaskets (Helicoflex). And the alloy can be directly welded to the niobium. The paper will present the surface analysis made on NbTi samples after the chemical treatment and on a Nb / NbTi weld. | ||
| TUP081 | Chemical Vapor Deposition Techniques for the Multilayer Coating of Superconducting RF Cavities | 635 |
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| Issued from the recent development of thin films technologies, multilayer nanostructures face today very challenging questions in materials science: ultimate size reduction, process control at an atomic scale, new size driven properties and system characterisation. For superconducting RF technologies a significant breakthrough could arise from the use of multilayered structures deposited inside Nb cavities. These multilayer nanostructures are based on the use of some 10 nanometers thick superconducting layers (d<λL) with a higher Tc than in Nb, alternating with insulating layers, required to decouple the superconducting films. We present here our first studies devoted to nano-layered superconductors produced by Chemical Deposition techniques: CVD and ALD. The basic principles of CVD and ALD will be presented together with new developments of the coordination chemistry for the ALD precursors, which is key point for the optimization of the individual layers. First results concerning NbN films obtained by CVD as well as CVD and ALD results concerning insulating materials used for Superconducting/insulating (S/I/S/I) multilayers structures will be reported. | ||
| WEIOC02 | Multilayers Activities at Saclay / Orsay | 789 |
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In the investigations on the high gradient SRF cavities, the superconducting multilayer is a promising alternative. The predictions show that an SIS (Superconductor/Isolator/Superconductor) nano-composite could improve the efficiency limited by the bulk Nb it-self used today for accelerating cavities. We start, at the IPNO lab in collaboration with the CSNSM lab (CNRS) and Irfu lab (CEA), an experimental study to test the screening effect on multilayer assemblies. Based on 3rd harmonic magnetometer and a TE011 SRF cavity, measurements of first critical magnetic field HC1 and surface resistance of samples have been performed. Along with these first results, we are starting the development of a MBE deposition. This set-up is devoted to optimise the best organisation of the multilayer to produce the model sample, and to find, in a close future, a realistic solution to apply this technique on an accelerating SRF cavity.
Labex P2IO funding |
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Slides WEIOC02 [3.035 MB] | |