PhD: Design and development of high-performance heat exchanger for dilution refrigerator (M/F)

Job Description

Thesis Subject

The Institut Néel has a long standing expertise in the development of cryo-refrigerators and cryogenic devices at very low temperature. In the framework of the National Quantum Strategy (SNQ), the ASIS project (Strategic Supply of Stable Isotopes) goals, among others, are to reduce the dependence of dilution refrigerator on 3He, an essential isotope for their operation. At the same time, and still within the framework of the SNQ, high power dilution refrigerators should be developed. To meet these requirements, new developments of ultra low temperature heat exchanger are required. The PhD candidate will develop heat exchangers for integration into high power dilution refrigerators (ideally 10 mW at 100 mK), with a design that minimizes the needs of 3He. The work will involve improving the design and performances of the already well-known sintered powder heat exchangers (as an example silver) or developing new types of heat exchangers.
The objectives of this work are twofold :
- at both room and ultra low temperatures, the student will develop realization and characterization methods, for sintered samples, to identify key parameters to optimize. In addition, the student will study and describe the physical phenomena responsible for heat transfer at ultra-low temperatures.
- Based on selected experimental key parameters and the modeling, the student will design and implement the prototype heat exchangers, which will be installed, instrumented and characterized within a full dilution refrigerator system (T below 10 mK). This scientific research includes a strong experimental component but also requires a solid understanding of modeling to describe and mimic the observed physical behaviors.

The thesis has a strong experimental component but requires a solid understanding of modeling concepts in order to describe the observed physical behaviors. The key skills identified are:
- Cryogenics
- Solid-state physics
- Instrumentation / Programming
- English

Your Work Environment

The Institut Néel has a long tradition of developing very-low-temperature devices. In the 1980s, the Center for Research on Very Low Temperatures (one of the laboratories integrated into the Néel Institute in 2007) was among the world's leading laboratories in the development of sintered silver heat exchangers (PhD works by H. Godfrin, G. Frossati, G. Vermeulen, etc.). These devices enable dilution refrigerators to reach the lowest temperatures, with records below 2 mK. As part of the Quantum Plan, the ASIS (Strategic Supply of Stable Isotopes) project aims, in particular, to reduce the dependence of dilution refrigerators on 3He supplies, an isotope that is essential for their operation. At the same time, a need for high-power dilution refrigerators has been identified, also as part of the Quantum Plan. To meet these needs, further development is required on very low-temperature heat exchangers, which are key components for optimizing the performance of dilution refrigerators at the lowest temperatures.

Institut NÉEL is a CNRS unit (UPR 2940) under agreement with the University Grenoble Alpes. The laboratory is related to the CNRS Physique. It is located in Grenoble, in the heart of a unique scientific, industrial and cultural environment. It is one of the largest French national research institutes for fundamental research in condensed matter physics enriched by interdisciplinary activities at the interfaces with chemistry, engineering and biology. It consists of 450 employees, including 175 researchers.
CNRS is a public, scientific and technological organization.
The core mandate is to identify, to carry out or to have carried out, either alone or with partners, all research that advances science or contributes to the country's economic, social, and cultural progress. Internationally recognized for the excellence of its scientific research, the CNRS is a reference in the world of research and development, as well as for the general public.

The hosting team at Institut Néel is UBT - Ultra-Low Temperatures, which forms part of the MCBT department.

Compensation and benefits

Compensation

2300 € gross monthly

Annual leave and RTT

44 jours

Remote Working practice and compensation

Pratique et indemnisation du TT

Transport

Prise en charge à 75% du coût et forfait mobilité durable jusqu’à 300€

About the offer

About the CNRS

The CNRS is a major player in fundamental research on a global scale. The CNRS is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to bring together different disciplines to address the most important challenges of the contemporary world, in connection with the actors of change.

CNRS

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