This post-doctoral subject concerns the development of Monte-Carlo ray-tracing methods for modeling radiation heat transfer in the context of severe accidents. Starting from a well-developed software framework for Monte Carlo simulation of particle transport in the context of reactor physics and radiation protection, we will seek to adapt existing methods to the problem of radiative heat transfer, in a high-performance computing framework. To do this, we will develop a hierarchy of approximations associated with radiative heat transfer that are intended to allow the validation of simplified models implemented in the context of the numerical simulation of severe accidents in nuclear reactors. Focusing on algorithm and simulation performance, this work is intended to be a "proof of principle" of the possible software mutualization around the Monte-Carlo method for particle transport on the one hand and radiative heat transfer on the other hand.
3D sequential integration is envisaged as a possible solution until the end of CMOS roadmap. Different process modules have been developped @ 500°C for planar FDSOI technology in a gate first process. However, regarding bottom transistor level stability in CoolcubeTM integration, and yield consideration, the need to reduce further the top transistor temperature down to 450°C should be explored.
The post-doc will have in charge the development of specific technological modules at low temperature both 500°C and 450°C for FDSOI planar devices to acquire a solid knowledge in low temperature CMOS process integration. The specific low temperature gate module will be addressed on planar devices. The threshold voltage modulation will also be studied.
The work will be performed in collaboration with the technological platform process of LETI for the low temperature modules development. The electrical characterization in collaboration with the characterization laboratory and the TCAD simulations team of LETI.
Vanadium alloys, investigated in the scope of application in fusion reactors, are potential candidates for fuel cladding of future sodium cooled or gas cooled fasts reactors. Then, in 2009, CEA launched a program aiming to assess this solution according to future reactor requirements.
Preliminary investigation of V-4Cr-4Ti plates was done at DMN/SRMA/LA2M (i) on a reference Japanese grade and (ii) on a specific grade fabricated for CEA study. Works haw focuses on recrystallisation structure after cold working (grain size and morphology, effect of annealing temperature), and on fine microstructure (occurrence of Ti(O,C,N) precipitation). In 2011, fabrication of vanadium tube by hot extrusion is planned to be relevant of the final cladding geometry. The proposed post-doc investigation aims to monitor the fabrication and to specify the impact of fabrication process on microstructure, recrystallisation dynamic and mechanical properties.
The activity of the postdoc will be focused on electrical characterization and physical modeling of devices with integrated bistable oxides (ie NiO, HfO2): mainly he will address both the hardware & methodology to address the non-volatile memory performances (ie write/erase, data retention and endurance), and he will perform measurements on several devices featuring different bistable oxides (ie NiO, HfO2…). Note that particular attention will be devoted to pulsed measurements tailored for “non-polar” or “bipolar” devices. After having collected sufficient ensemble of data on memory performance, he will try to interpret them in the simplest form with possibly semi-analitycal models in order to catch the basics of physics relying behind the electrical data.