Karlsruhe Institute of Technology

The Karlsruhe Institute of Technology conducts application-oriented developments as well as fundamental research in cryogenic applications, particularly in connection with superconductivity and fusion technology. The activities span over the areas of nuclear fusion, tritium technology, vacuum science and technology, new electric power equipment and high field magnets, including the development of superconductors, cryogenic components and circuits, and the characterization of low temperature structural materials. Moreover, KIT offers a number of education/training courses, as well as testing and research services.

In the area of superconducting (sc.) materials, KIT conducts fundamental research and developments of sc. wires, tapes and cables, focusing on MgB 2 -wires, YBCO- and BSCCO-tape conductors and high-current cables for AC operation. This includes specialized conductor concepts for a variety of applications and optimization of the conductor- and cable-performance with respect to transport current behavior, losses, contact technology and mechanical strength. Application-oriented developments include e.g. sc. fault-current limiters and transformers, space technology, sensor technique and liquid hydrogen systems.

Another field is the development of high-field sc. magnet systems with ≥ 25 Tesla. Applications are nuclear magnetic resonance (NMR) spectroscopy, fundamental and structural research, and devices for synchronized radiation sources and accelerators.

In nuclear fusion, KIT contributes to the development, construction and test of large sc. magnet systems used to include the plasma in fusion machines, such as ITER, W7-X and JT-60SA. High-temperature superconductors (HTS) are used to build HTS current leads feeding the coil current from room-temperature to the sc. magnets. KIT has developed and successfully tested a HTS current lead demonstrator (68 kA) for ITER, the HTS current leads for W7-X (18.2 kA) and for JT-60SA (20 and 26 kA). The activities are supported by a wide range of material characterizations down to 4 K in the CryoMaK test facility.

For the fuel cycle of fusion reactors, the Tritium Laboratory Karlsruhe (TLK) develops cryogenic technologies for the separation of hydrogen isotopes. Another major TLK activity is the development and operaton of the tritium cycle for KATRIN, the Karlsruhe Tritium Neutrino Experiment.

The spectrum of activities is completed by the development of cryo vacuum pumps, especially for applications with very high gas throughputs or very low ultimate pressures, respectively. KIT offers the complete modelling, design and manufacturing of large cryogen-supplied cryopumps, used for instance in nuclear fusion and in particle accelerators, together with a broad range of experimental capabilities to characterize and test such pumps.

With regard to cryogenics, KIT develops cryostats and cooling systems in these application areas, reaching from 1.8 K HeII systems up to HTS application requirements. A recent development is the neon cooling system for the tritium source of KATRIN. Research activities presently include the safety of helium cryostats, cryogenic mixed refrigerant cycles, insulation concepts and measuring techniques.

Education/Training Courses in the Field of Cryogenics

Courses in the KIT Masters Program

Refrigeration B – Industrial gas processing
Language: German
Time: During summer terms (April to July)
Content: Gas liquefaction processes, process analyses, refrigerators and mixed-refrigerant cycles, gas separation by low-tempera-
ture rectification, air separation and extraction of noble gasses, processing and separation of natural gas, ethylene producti-
on, storage and transport of liquefied gasses
Contact: Prof. Dr.-Ing. Steffen Grohmann (steffen.grohmann@kit.edu, Institute of Technical Thermodynamics and Refrigeration)

Physical Foundations of Cryogenics
Language: English
Time: During summer terms (April to July)
Content: Relation between energy and temperature, energy transformation on microscopic and on macroscopic scales, physical
definitions of entropy and temperature, thermodynamic equilibria, reversibility of thermodynamic cycles, helium as classical
and as quantum fluid, low-temperature material properties, cooling methods at temperatures below 1 K
Contact: Prof. Dr.-Ing. Steffen Grohmann (steffen.grohmann@kit.edu, Institute of Technical Thermodynamics and Refrigeration)

Cryogenic Engineering
Language: English
Time: During winter terms (October to February)
Content: Cryogenic applications; regenerative cooling with cryocoolers; fundamentals of low-temperature plant and cryostat design,
including fluid mechanics and heat transfer, thermal contacts and thermal insulation, cryogenic pumping of gasses, regula-
tions, design components and safety; general principles of measurement and uncertainties as well as cryogenic tempera-
ture, pressure and flow measurement
Contact: Prof. Dr.-Ing. Steffen Grohmann (steffen.grohmann@kit.edu, Institute of Technical Thermodynamics and Refrigeration)

Courses via the VDI Association

VDI Seminar Kryotechnik (VDI Seminar Cryogenics)
Language: German
Time: Yearly 3-days seminar (February/March), since 1973
Content: Technical introduction to the fundamentals of refrigeration including liquefaction, refrigeration units and cryocoolers,
thermodynamic properties of cryogens, concepts of heat transfer and thermal insulation, cryostat design, safety, measure-
ment and control. Target group: Natural scientists, engineers and technicians working at cryogenic facilities.
Contact: Dr.-Ing. Holger Neumann (holger.neumann@kit.edu, Institute of Technical Physics)

VDI Forum Cryogenics
Language: English
Time: Yearly 3-days seminar (September)
Content: See VDI seminar cryogenics
Contact: Dr.-Ing. Holger Neumann (holger.neumann@kit.edu, Institute of Technical Physics)

Summer Schools

ESAS Summer School on Materials and Applications of Superconductivity
Language: English
Time: Yearly, every 3rd year at KIT
Contact: Prof. Dr.-Ing. Mathias Noe (mathias.noe@kit.edu, Institute of Technical Physics)
Karlsruhe International School on Fusion Technologies
Language: English
Time: Yearly (http://summerschool.fusion.kit.edu)

Testing and Research Services

Cryogenic infrastructure:

2 kW @ 4.4 K refrigerator
300 W @ 1.8 K refrigerator

TOSKA facility for large superconducting magnet tests:

Usable volume: Ø 4.3 m × 6.6 m height
Temperatures down to 1.8 K and currents up to 80 kA

Superconducting high field magnet facilities:

Superconducting test facilities Jumbo, HOMER I, HOMER II (T ≤ 4.2 K, B ≤ 20 T)
Magnet test facility MTA I for magnet systems up to 20 T
Technical workshop for coil manufacturing

Facilities for superconducting materials and energy applications:

Preparation methods for materials, conductors and cables
Material analytics, microscopy and chemistry
Widespread characterization of superconductivity
Test field for superconducting devices

Facilities and services for the development of cryo vacuum pumps:

Measurement of sorption isotherms on porous cryosorbent materials down to ultrahigh vacuum conditions and variable temperatures (3.5 to 90 K)
TIMO-2 test facility (test volume 10 m 3 , He flow rates of up to 200 g/s @ 4.5 to 15 K, 80 K and 100 K), licensed also for hydrogen operation
Development of build-to-print cryopump designs tailor-made to the customer‘s requirements
Manufacturing of a cryopumps or supervision of contracted manufacturing works

Cryogenic high voltage laboratory:

Two experimental high voltage chambers with HV up to 200 kVrms, partial discharge measurements

CryoMaK facility for low-temperature material characterization:

Mechanical test at temperatures from 300 K to 4.2 K using different facilities to investigate tensile, fracture and fatigue properties
Measurement of thermal and electrical conductivity, as well as thermal expansion
Electromechanical tests of superconducting wires, tapes or cables (≤ 10 kA) in magnetic fields (≤ 14 T) and applied tensile load (≤ 100 kN)

Other cryogenic test facilities:

THISTA calorimeter for cryogenic insulation tests
Measurement of low-temperature phase equilibria
Calibration laboratory for temperature and flow measurement