Overview

The Magnetically Shielded Room (MSR) of the Chair of Precision Measurements at Extreme Conditions is among the most magnetically quiet environments worldwide.
It was designed to provide ultralow magnetic fields, high stability, and excellent spatial homogeneity for precision measurements in fundamental and applied physics.
The facility combines multi-layer passive shielding, active field stabilization, and highly optimized degaussing procedures to achieve residual fields well below the nanotesla range.

Shielding Architecture

The MSR consists of four nested layers of high-permeability µ-metal and one layer of aluminum, forming a cubic enclosure of approximately 2 × 2 × 2 m³.
Each layer is electrically isolated and mechanically decoupled to minimize vibration-induced noise and eddy current coupling.
The total shielding factor exceeds 10⁶ for static fields, and an additional active compensation can be implemented.

Key design aspects include:

• High-permeability µ-metal for static field shielding.
• Aluminum layer for suppression of time-varying fields (eddy current damping).
• Double door system and non-magnetic mechanical interfaces to maintain integrity.
• Integrated field feedthroughs for sensors, light guides, and power without degrading performance.

Degaussing System

The µ-metal layers are equipped with a dedicated degaussing coil system.
The procedure uses damped AC currents to gradually demagnetize the material and minimize residual magnetization (remanence).
The system supports independent control along three spatial directions, enabling iterative optimization of each layer.

Research within the group has demonstrated that fine-tuning the degaussing waveform and phase coherence between layers substantially improves long-term field stability and reduces Barkhausen noise.

Performance

coming soon….

Publications and finished Theses

Involved Persons and Former Members

Currently Involved persons: Dr. Florian Kuchler, Maximilian Huber, Philipp Wunderl

Former Members: