Characterization Laboratory at Cryogenic Temperature (LabCaF)

Context

Characterization of superconducting samples by measurement of the « Residual Resistivity Ratio » (RRR) (Φ ≤ 0.15 m, h ≤ 1 m, 4.5 K ≤ T ≤ 300 K) and measurement of the first critical field H_C1 (Φ ≤ 0.3 m, h ≤ 1.33 m, 2 K ≤ T ≤ 40 K).

Technical means

Two small cryostats :

- One cryostat (useful dimensions: h = 1.33 m and Φ = 30 cm), with a removable bottom insert, currently used for first critical field H_C1 measurements by local magnetometry (B ≤ 150 mT), but adaptable to other experiments,

- One cryostat (useful dimensions: h = 1 m and Φ = 15 cm) used for RRR measurements,

Nitrogen and helium dewars (T ≥ 1.9 K),
Precision voltmeters and ammeters, temperature controllers,
Lock-in amplifier,
Labview data acquisition system.

Achievements, related projects

LabCaF devices are mainly used in the framework of R&D projects (in the early stages).

For example, they were used for the characterization of nano-composite superconductors in the framework of the EuCard-2 project (measurement of the first critical field H_C1 by local magnetometry).

Industrial services were also performed at the LabCaF (in particular on the RRR experiment).

Technical steps, expertise

Positioning of the sample in the cryostat,

Remark regarding H_C1 measurements: some connections (electrical circuit, instrumentation…) can be done under a mounting plate, before placing the removable bottom insert in the cryostat.

Liquid nitrogen and helium cooling (this stage lasts about 2 days),
Data acquisition (2-3 hours for RRR measurements, one day for H_C1 measurements).

Contact:

#4008 - Last update : 06/14 2017

Division of accelerators, cryogenics and magnetism

Institute of research into the fundamental laws of the Universe