W-7X Station

Context

Trials on current intensity, insulation voltage, mechanical stress, pressure drop and temperature for large magnets (Φ ≤ 5 m, h ≤ 4.1 m) cooled with supercritical helium forced flow (4.5 K ≤ T ≤ 7.6 K), or cooled with saturated helium to T = 4.2 K.

Technical means

The power supply is temporarily unavailable. The station components were designed to operate with I ≤ 25 kA,
Dedicated Magnet Safety System and Magnet Control System,
Two cryostats with nitrogen shields (Φ ≤ 5 m, h ≤ 4.1 m),
A refrigerator (P=200 W at T = 4.2 K).

Additional facility:

The station is located under a crane (m ≤ 20 t).

Achievements, related projects

Cryogenic tests of 70 magnets in the framework of the Wendelstein 7-X project. These tests revealed in particular helium leaks from the magnet hydraulic circuits, insulation problems between the conductor layers and insulation to ground problems in the protection cables, and magnets themselves.
Tests of the GLAD magnet cold mass in the framework of the R3B project.
Tests of the ISEULT magnet.

Technical steps, expertise

Positioning of the magnet in the cryostat, fluid, energy, diagnostic adjustment and junction,
Adjustment and tuning of measurement and security chains,
Check of the magnet behavior at high temperature and / or under vacuum,
Conditioning of the refrigerator and the high intensity electric supply,
Cooling of the magnet with monitoring of the parameters,
Check of the system insulation at low temperature,
Tests of partial operation before the rise of the nominal current,
Rise of the nominal current,
Check of the “quench” behavior (according to the specifications),
Search for the maximal current or maximal operating temperature (according to the specifications).

Contact:

#3980 - Last update : 07/21 2017

Division of accelerators, cryogenics and magnetism

Institute of research into the fundamental laws of the Universe