Task
Temperature sensors for cryogenic applications are required for a wide variety of
projects, particularly in research. In complex large-scale research facilities,
several thousand of these sensors are used. Since the measured temperatures are often
critical parameters for analyzing system behavior and other factors, high-precision
measurement is essential. In recent years, ILK Dresden has continuously
developed and improved test setups for the calibration of cryogenic sensors and
has used them for a wide range of calibration measurements. Key setups include a
semi-automated measurement station that operates with liquid helium and enables minimum temperatures
down to approximately 1.4 K, as well as a fully automated test bench for the simultaneous
measurement of up to about 40 sensors, whose cooling down to approximately 3.5 K is provided by a
pulsed tube cooler. In the process, important partial solutions such as the thermal damping of
design-induced temperature oscillations have been implemented.
The current goal is to establish another fully automated calibration station with a pulsed tube cooler
that can also achieve temperatures below 3.5 K. This requires a
supplementary helium circuit with a Joule-Thomson valve. Depending on the
helium isotope used, minimum temperatures of approximately 1.5 K or 0.8 K can be achieved.
Areas of expertise
First, thermal calculations will be performed for selected components of the Joule
Thomson cycle, such as the design of the
heat exchanger. As part of the design process, a decision must also be made as to whether to use the isotope 3He, which vaporizes at lower
temperatures, or the more cost-effective 4He. The
complete sizing of the cycle is expressly not the goal of the lab; rather,
the aim is to develop a basic understanding of the thermal relationships
through active participation. This is followed by participation in the setup of the calibration station. The focus
of the lab work should be on its optimization based on systematic experimental
investigations and their analysis. This includes both the variation of thermodynamic
parameters and possible modifications to individual components. It is also important to
note the strong temperature-dependent variation of many influencing factors. Finally,
proposals for the best possible operating regime of the measurement station must be derived.
Qualifications
- Degree in physics, cryogenics, or engineering
- Proficiency in English or German is required
- A reliable and responsible work ethic is essential, particularly with regard to compliance with safety procedures
- The ability to work proactively, independently, and in a goal-oriented manner is expected
- The ability to communicate clearly and effectively, both verbally and in writing, is expected.
Notes
The specific tasks to be completed can be tailored to individual skills and interests.
Upon request, the work can also be conducted in English.
Application | Contact Person
Dr.rer.nat. Andreas Kade
Head of Main Department
Dr. rer. nat. Matthias Schneider
Low Temperature Physics | Material Investigations
