First space concentrator prototype using III-V/Si cells
2019 EUROPEAN SPACE POWER CONFERENCE (ESPC)
Authors: Bermudez-Garcia, Anderson; Voarino, Philippe; Cariou, Romain; Vauche, Laura; Medjoubi, Karim; Jany, Christophe; Raccurt, Olivier
Abstract
Concentrating PhotoVoltaics (CPV) can increase the efficiency of power systems in space while reducing their cost. This paper presents the first concentrator prototype using III-V/Si cells for space applications. This new approach will significantly reduce cost by concentrating sunlight then decreasing cell material, and in particular using III-V/Si triple-junction (3J) cells will allow the usage of Silicon, which is an abundant, twice less dense and low-cost material than the typically used Germanium. The efficiency of III-V/Si solar cells used is 25.7% @AM0. In our refractive module design, Compound Parabolic Concentrator (CPC), twelve 1.5x13mm(2) cells are embedded in a Dow Corning (R) 93-500 silicone optics that provides an similar to 8x concentration factor with an optical efficiency of 68%. Additionally, this linear-focus lens enables the use of single-axis sun tracking.
Lepton masses and mixing from modular S-4 symmetry
NUCLEAR PHYSICS B
Authors: Penedo, J. T.; Petcov, S. T.
Abstract
We study models of lepton masses and mixing based on broken modular invariance. We consider invariance under the finite modular group Gamma(4) similar or equal to S-4 and focus on the minimal scenario where the expectation value of the modulus is the only source of symmetry breaking, such that no flavons need to be introduced. After constructing a basis for the lowest weight modular forms, we build two minimal models, one of which successfully accommodates charged lepton masses and neutrino oscillation data, while predicting the values of the Dirac and Majorana CPV phases. (C) 2018 The Authors. Published by Elsevier B.V.