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A : Current research in High Energy Cosmic Ray Physics touches on fundamental questions regarding the origin of cosmic rays, their composition, the acceleration mechanisms, and their production. Unambiguous measurements of the energy spectra and of the composition of cosmic rays at the "knee" region could provide some of the answers to the above questions. So far only ground based observations, which rely on sophisticated models describing high energy interactions in the earth's atmosphere, have been possible due to the extremely low particle rates at these energies.A calorimetry based space experiment that could provide not only flux measurements but also energy spectra and particle identification, would certainly overcome some of the uncertainties of ground based experiments. Given the expected particle fluxes, a very large acceptance is needed to collect a sufficient quantity of data, in a time compatible with the duration of a space mission. This in turn, contrasts with the lightness and compactness requirements for space based experiments.We present a novel idea in calorimetry which addresses these issues whilst limiting the mass and volume of the detector. In this paper we report on a four year R&D program where we investigated materials, coatings, photo-sensors, Front End electronics, and mechanical structures with the aim of designing a high performance, high granularity calorimeter with the largest possible acceptance. Details are given of the design choices, component characterisation, and of the construction of a sizeable prototype (Calocube) which has been used in various tests with particle beams.

The paper develops a comprehensive approach for the servo-fluid-elastic modeling of electromagnetically levitated secondary adaptive mirrors. The system modeling includes the mirror structural dynamics model, its interaction with the fluid film interposed between the mirror and its reference backplate and disturbances due to local air turbulence. The accuracy of the proposed fluid dynamic model is assessed by comparing it with a significant sample of high fidelity 3D Navier-Stokes analyses. The simulation tool is then used to demonstrate the effectiveness and robustness of a recently proposed control, based on a system dynamics cancellation and an iterated steady state feedforward contribution. The simulations clearly highlights the improvements achievable implementing the new control scheme.

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