Postdoctoral researcher on the PSICHE beamline

SOLEIL is the French national synchrotron facility, located on the Saclay Plateau near Paris. It is a multi-disciplinary instrument and research laboratory whose mission is to conduct research using synchrotron radiation, to develop state-of-the-art instrumentation on the beamlines, and to make these developments available to the scientific community. SOLEIL synchrotron, a unique tool for both academic research and industrial applications across a wide range of disciplines including physics, biology, chemistry etc., is used by over 5 000 researchers coming from France and abroad. SOLEIL is based on a synchrotron source that is at the cutting edge both in terms of brilliance and stability. This large scale facility, a partner of the Université Paris Saclay, is a “publically owned” private company, founded by the CNRS and the CEA and counts about 500 staff members.

Synchrotron SOLEIL seeks to hire a postdoc in materials science in collaboration with the CEA. This position is opened for the PSICHÉ beamline. The contract will last 24 months.

The PSICHÉ (Pressure Structure and Imaging by Contrast at High Energy) beamline is dedicated to X-ray diffraction under extreme conditions (pressure-temperature) and to tomography at high energy, from ambient to extreme conditions. The source is an in-vacuum wiggler that is used to produce a wide variety of beam modes, from a large parallel white/pink beam to a microfocused monochromatic beam. We have two hutches, one dedicated to white/pink beam (energy range: 15-120 keV) and another to monochromatic beam (20-50 keV). Extreme pressure and temperature conditions can be generated using different equipment: a 1200-ton multi-anvil press, Paris-Edinburgh presses (including tomography at extreme conditions), diamond anvil cells (including a double-sided laser heating facility). The use of multiple techniques, and the combination of complementary techniques, are important features of the beamline.

The scope of the scientific cases is very large: from biology and paleontology to materials science, high-pressure physics and geophysics.

The PSICHÉ team is currently made up of three scientists including the beamline manager, one technician, two post-docs, one PhD student and one emeritus.

I. Mission

The postdoc will work on the PSICHÉ beamline under the joint supervision of Nicolas Guignot (beamline manager) and Agnès Dewaele (CEA DAM).

She.He will actively participate to the user-support program (X-ray diffraction using a multi-anvil press and diamond anvil cells) and will be involved in the scientific, technical, and methodological aspects of the beamline team activities. That means preparing the beamline for the experiments, helping the users with the management of the presses, data acquisition and data treatment if necessary.

She.He will develop a research program (see next section). She.He will be granted in-house research beam time and will have to submit proposals to the peer review committees. She.He will publish her.his results and present them at national and international conferences.

II. Responsibility and Tasks

The postdoc will work on two topics:

• New pyrometry diagnostics + X-ray diffraction in laser heated diamond anvil cells

The PSICHÉ beamline has an innovative setup allowing for real-time measurement of surface temperature maps of the laser heated samples. By combining this new technique with X-ray diffraction and thermo-mechanical modeling it is possible to have access to information complementary to crystal structure analysis and phase diagrams, e.g. crystallization kinetics or thermal properties of materials under extreme conditions.

• Acoustic emissions measurements under extreme conditions

The “large volume presses” experimental station of the PSICHÉ beamline is multi-technical and designed to precisely measure various physical properties of materials, in particular liquids, at extreme conditions: high-speed radiography (viscosity), tomography, including high-speed (microstructure, density), x-ray diffraction (structure, density), Beer-Lambert absorption (density) and recently sound velocity measurements (elasticity). The beamline seeks now to implement acoustic emissions measurements into its large volume presses, with applications in materials sciences, solid-state physics and Earth sciences.

III. Education and Experience

The candidate should have a PhD degree in physics / chemistry / materials science or Earth sciences, and post-doctoral experience. She/He should have a good knowledge and skills in the field of high-pressure experimentation using large volume presses and/or diamond anvil cells, in a laboratory setup or if possible in a synchrotron radiation facility, as well as a good knowledge of the condensed matter physics basics.

The postdoc will join an enthusiast and growing pluri-disciplinary team, benefiting from several national and international partnerships.

We’re looking for someone showing curiosity, dynamic, autonomous, and liking working in a team.