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Reference : UMR7249-JEAGEF-005
Workplace : MARSEILLE 13
Date of publication : Monday, July 29, 2019
Scientific Responsible name : Jean-Michel Geffrin
Type of Contract : PhD Student contract / Thesis offer
Contract Period : 36 months
Start date of the thesis : 1 October 2019
Proportion of work : Full time
Remuneration : 2 135,00 € gross monthly
Description of the thesis topic
Exploring the formation of planets with microwave measurements of protoplanetary dust analogues
Objectives: To help to understand the observations from the best telescopes, dust analogues will be made by 3D printing. These "analogues" will have realistic and controlled shapes and sizes. Their interactions with electromagnetic waves will be measured in the anechoic chamber of the Centre Commun de Ressources en Microondes (CCRM, Marseille). The results will be used to quantify the shape and size of the dust particles in the discs. The benefits of the project are numerous and extend beyond astrophysics.
Skills: The candidate will be required to develop a wide range of skills. He will be very involved in the analogues manufacturing, in their measurement, and in the publication of the direct results of these measurements. The candidate must have a good knowledge of electromagnetism, CAD, material science... The experience of our last doctoral student shows that the employment prospects, following a similar thesis, are excellent. He has been directly hired with permanent position in a large multinational company and he is working on the microwave control of semiconductors.
Role of the doctoral student:
1/ In close collaboration with IPAG researchers: a) identify the properties of the dust to be reproduced by 3D printing (size, shape, compactness of the particles), and b) from the disc images identify the observations that similar particles should attempt to reproduce.
2/ Once these properties have been identified, the candidate will set up the manufacturing protocol for the first analog particle (CAD file for printing, size and refractive index). The doctoral student will ensure the manufacturing in liaison with the LabSTICC team and/or our other partners.
3/ The properties of the analogue should then be validated (shape, indices), and the optical properties measured in the anechoic chamber of the CCRM in collaboration with the team from the Institut Fresnel. Several particles will have to be measured, with an increasing level of complexity. Steps 1 to 3 will be repeated as often as necessary.
4/ As the measurements are made, the results will be published in specialized journals and presented at major international conferences (e.g., JQSRT for reviews, ELS for conferences).
5/ The ultimate objective is the comparison and adequacy of the diffraction measurements of the analogues with the astrophysical results. The results will be published in specialized astro journals (Astronomy & Astrophysics, ICARUS, Nature Astronomy).
Background: This thesis will be carried out as part of the EXPERTS project (EXploring Planet formation with lab ExpeRimenTS) which is an interdisciplinary project to study the early stages of planets formation, the growth of dust in protoplanetary discs. Through an innovative approach, which consists in measuring the optical properties of analogues of such dust with microwaves, we will study the signatures of dust growth in proto-planetary discs. The exact growth processes are poorly known and any new direct information, particularly on centimetric dust, will be fundamental
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