Performance improvement of the multicell cavity prototype for proton Linac projects

The CEA-Saclay / IPN-Orsay collaboration allowed to manufacture a multicell superconducting RF cavity prototype for proton linac. Since the first experimental results [1], obtained in a vertical cryostat and the horizontal cryostat CryHoLab, the accelerating field Eacc has been recently increased up to 19 MV/m with a quality factor Q0 = 9.109 and a limitation by quench. However some improvements are still needed, in particular to suppress the field emission above 16 MV/m

Computer predictions of thermo-mechanical behavior and residual stresses in spray coating process

This paper presents a numerical method in order to forecast the thermo-mechanical behavior and the residual stresses in the thermal spray coating process by using high velocity oxygen fuel (HVOF). A set of coupled equations of the heat conduction and stress/strain and solidification based on the metallo-thermo-mechanical theory is introduced into the simulation of thermal spraying. Here, an inelastic constitutive equation with capacity to represent relation of stress/strain during rapid solidification is employed. The numerical modelling based on the finite element method is proposed to solve the heat conduction associated with solidification in the sprayed layer and residual stresses on the interface between multi-layer materials, especially. In this paper, the simulated results of the temperature field, solidified domain and residual stresses in the sprayed layer including interfacial combinations between substrate and spray layer are presented, and the validity of the calculated results is discussed in comparison with the measured results obtained by X-ray diffraction

Varieties of capitalism in an internationalized world: domestic institutional change in European telecommunications

This article examines how internationalization affects domestic decisions about the reform of market institutions. A developing literature argues that nations maintain different \u201cvarieties of capitalism\u201d in the face of economic globalization because of diverse domestic settings. However, in an internationalized world, powerful forces for change applying across border scan affect decision making within domestic arenas. The article therefore analyzes how three factors (transnational technological and economic developments, overseas reforms, and European regulation) affected institutional reform in a selected case study of telecommunications regulation in Britain, France, Germany, and Italy between the 1960s and 2002. The author argues that when different forms of internationalization are strong and combined, they can overwhelm institutional inertia and the effects of different national settings to result in rapid change and cross-national convergence in market institutions. Hence different varieties of capitalism may endure only when international pressures are low and/or for limited periods of time

Direct Observations of Asteroid Interior and Regolith Structure: Science Measurement Requirements

International audienceOur knowledge of the internal structure of asteroids is, so far, indirect – relying entirely on inferences from remote sensing observations of the surface, and theoretical modeling of formation and evolution. What are the bulk properties of the regolith and deep interior? And what are the physical processes that shape asteroid internal structures? Is the composition and size distribution observed on the surface representative of the bulk? These questions are crucial to understand small bodies’ history from accretion in the early Solar System to the present, and direct measurements are needed to answer these questions for the benefit of science as well as for planetary defense or exploration.Radar is one of the main instruments capable of sounding asteroids to characterize internal structure from sub-meter to global scale. In this paper, we review the science case for direct observation of the deep internal structure and regolith of a rocky asteroid of kilometer size or smaller. We establish the requirements and model dielectric properties of asteroids to outline a possible instrument suite, and highlight the capabilities of radar instrumentation to achieve these observations. We then review the expected science return including secondary objectives contributing to the determination of the gravitational field, the shape model, and the dynamical state. This work is largely inherited from MarcoPolo-R and AIDA/AIM studies