The LISA project of gravitational waves detection has been selected in January 2024 by the European Space Agency as the third ‘Large’ mission of the ‘Cosmic Vision’ program, with a expected launch date in 2035. This mission relies on the capability to measure, using laser interferometry, the distance fluctuations between satellites 2.5 Mkm apart, with a picometer accuracy on seconds to hours timescales.

LISA is the product of an international development effort, France being part of the European collaboration providing the instrument. In this context, the CNES and about fifteen French laboratories are contributing to the validation of the scientific performance of the instrument prior to flight and are currently developing the required high-precision optical metrology benches and measurement systems.  The APC laboratory is more specifically in charge of providing the so-called "Beams Simulator" (BSIM), an ultra stable interferometric bench aiming at stimulating and stimulating the free space and fiber interfaces of the LISA optical bench. 

The performance of the metrological ‘core’ of the LISA instrument (named IDS : Interferometric Detection System) shall be tested and validated in the CNES premises using the IDS Engineering Model (from mid 2027 to end 2028), and, afterwards, the IDS Qualification Model (from mid 2029 to mid 2030).  

The proposed PhD subject covers the final stages of BSIM integration and tests, the preparation of and participation to the test campaign at the CNES and the scientific exploitation of the results. The main final objectives are to perform an in-depth analysis of the test data and use them to build prediction model, as accurate as possible, of the in flight metrological performance. It shall also lead to the definition of measurements that should be performed during the in-orbit commissioning phase to complement the results obtained on ground. This work is therefore included in the general validation strategy of the LISA instrument model.

Chronologically, the expected thesis work includes, but is not limited to, the following tasks :

• Review of the existing BSIM and IDS designs and their associated measurements capabilities and existing performance models

• Contribute to the experimental tuning, characterization and validation of the BSIM optical bench and its sub-systems.

• Study the existing tests procedure designed to validate the IDS in the CNES premises, evaluate their pertinence for in-depth performance modeling and checks

• Propose complementary experiments, build the associated numerical models supporting the (possible) need for specific tests 

• Design the analysis pipelines for the most accurate performance estimate.

• Participate to the Engineering Model test campaign at the CNES premises, perform real-time analysis to get a preliminary in-sight of the instrument performance and propose adaptation of the tests procedures if needed.

• Perform an in-depth, off-line, analysis of the tests results and infer, as accurately as possible, their impact on the predicted IDS performance.

• Deduce recommendations for the Qualification Model test campaign and in-flight commissioning phase

For these experimental tasks and their interpretation in terms of instrumental performance, the student shall rely on the scientific and technical teams of the LISA group at the APC laboratory (including engineering support in optics, mechanics, electronics, system engineering, data analysis, quality assurance, etc). This work will also be carried out in close collaboration with the other French laboratories, the CNES and the international institutes involved in the development of the LISA instrument.

For more Information about the topics and the co-financial partner (found by the lab !) :
PhD supervisor - hubert.halloinapc.in2p3.fr

Application shall be done through the CNES web interface before March 14th, 2025 ! :
https://recrutement.cnes.fr/fr/annonce/3425261-25-207-contribution-to-th...

Prepare a resume, a recent transcript and a reference letter from your M2 supervisor/ engineering school director and you will be ready to apply online  before March 14th, 2025 Midnight Paris time !