MuRoom® Magnetically Shielded Rooms (MSRs)

A MuRoom® is a modular magnetically shielded room (MSR) designed to reduce external magnetic interference and create a controlled, low-field environment for sensitive equipment, experiments and measurements. Magnetically shielded rooms are also sometimes described as magnetic shielded rooms or, more simply, shielded rooms.

MuRooms® use multiple layers of high-permeability magnetic shielding material to redirect magnetic fields around the enclosed space. Depending on the application, the room can also incorporate degaussing and active magnetic compensation systems to further reduce the residual magnetic field.

Unlike shielding incorporated into the fabric of a building, a MuRoom® is a freestanding, modular structure installed within an existing laboratory or facility. Its size, layout, doors, service penetrations and finishes can be configured to suit the application and available space.

MuRoom® magnetically shielded rooms are used wherever sensitive measurements or equipment need to be protected from the Earth’s magnetic field and other sources of low-frequency magnetic interference.

Typical applications include:

• Optically pumped magnetometer magnetoencephalography (OPM-MEG)
• Conventional SQUID-based MEG
• Biomagnetic and neuroscience research
• Quantum sensing and quantum technology
• Atomic magnetometry
• Fundamental physics and particle research
• Paleomagnetic research
• Electron microscopy
• Calibration and testing of sensitive magnetic sensors
• Low-field measurement and experimental laboratories

Each MuRoom® can be configured around the equipment, required shielding performance, measurement area and working environment.

Yes. MuRooms® can be specifically designed and optimized for OPM-MEG applications, where extremely low and stable magnetic fields are required to measure the weak magnetic signals generated by the brain.

The passive, multiple-layer shielding construction reduces external magnetic interference, while an integrated degaussing system can further reduce the residual magnetic field within the room. Active coil compensation can also be incorporated where lower residual fields and reduced field gradients are required, particularly for studies involving movement.

The required configuration will depend on the OPM system, the type of study being undertaken, the desired measurement area and the magnetic conditions at the installation site.

The performance of a MuRoom® depends on its size, number of shielding layers, construction, degaussing system and the magnetic conditions at the installation site.

Performance is normally defined using two measurements: the residual static magnetic field inside the room and the shielding factor at specified measurement frequencies. Depending on the specification, passive MuRooms® can achieve residual fields in the low nanotesla range after degaussing.

Where required, active coil compensation can further reduce residual fields and field gradients. Performance requirements are agreed for each project and verified through testing and measurement after installation.

The primary shielding material used in a MuRoom® is a high-permeability nickel-iron alloy, commonly known as MuMetal®. This material redirects magnetic flux around the enclosed space, reducing static and low-frequency magnetic fields within the room.

A MuRoom® typically contains multiple, independently constructed MuMetal® shielding layers separated by controlled air gaps. Copper or aluminum layers can also be incorporated to provide additional attenuation of alternating magnetic fields.

The shielding layers are supported by a modular structural framework and protected by internal and external finishes suitable for a laboratory environment. The precise combination of materials, layer thicknesses and spacing is selected according to the room size, application and required performance.

Each shielding layer progressively reduces the magnetic field passing into the room. The outer layers redirect much of the surrounding magnetic field, while the inner layers further reduce the field to achieve the required internal environment.

The controlled spacing between the layers is also an important part of the design, as it improves the effectiveness of the overall shielding system. Using multiple independently constructed layers provides substantially greater performance than a single layer of equivalent overall thickness.

The number of layers and the spacing between them are engineered according to the room size, external magnetic environment and required shielding performance.

MuRooms® are available in a range of standard sizes, from compact rooms for individual sensors or seated measurements through to larger walk-in rooms suitable for complete experimental systems and multiple occupants.

Please see the standard room-size table on our MuRoom® webpage for the available internal dimensions and configurations.

Standard sizes provide a useful starting point, but door positions, service penetrations, internal layouts and finishes can be configured for the application. Where a standard size is unsuitable, a custom-sized MuRoom® can be designed.

Yes. In addition to our standard range, MuRooms® can be designed and manufactured to suit specific equipment, experiments, available space and performance requirements.

Custom MuRooms® are commonly used for specialist applications such as paleomagnetic research, electron microscopy and fundamental physics experiments, including neutron electric dipole moment (nEDM) research. They may be required to achieve exceptionally high shielding performance or simply to accommodate specialized equipment, experimental layouts or larger working areas.

The internal dimensions, geometry, number and arrangement of shielding layers, door position, service penetrations, ventilation and finishes can all be considered as part of the design. Each room is engineered on a project-by-project basis around the application, required performance and installation site.

A MuRoom® is a freestanding, self-supporting structure installed within an existing building or laboratory. It does not normally rely on the surrounding walls or ceiling for structural support and is not incorporated into the building fabric.

This modular construction minimizes permanent alterations to the facility and allows the room to be installed within a prepared space. The supporting floor must, however, be level and capable of carrying the weight of the completed room and its equipment.

Any project-specific fixing, structural or seismic requirements will be considered during the design and site-planning process.

Yes. MuRooms® are modular structures designed to be assembled within existing laboratories, research facilities and other buildings.

Before installation, the available space, ceiling height, floor loading, delivery route and access to the proposed location must be assessed. The location should also be evaluated for nearby sources of magnetic interference and vibration, as these may affect the equipment operating inside the room even when the required magnetic shielding performance is achieved.

Installation on an upper floor may be possible, subject to structural verification and a suitable route for bringing the individual components into the building. Magnetic Shields can undertake a site survey to confirm that the proposed location, access arrangements and surrounding environment are suitable.

Yes. A MuRoom® can be dismantled and reassembled in a new location, although relocation is a significant undertaking and requires careful planning.

The shielding components must be handled and protected correctly during dismantling, transport and reassembly. Some parts may also need to be replaced, particularly internal or external finishing panels and other components that cannot be removed and reused without damage.

The new location must be assessed for space, structural capacity, access, vibration and surrounding magnetic interference. After reassembly, the MuRoom® will require degaussing, recommissioning and performance verification. Its measured performance may differ because of the magnetic conditions at the new site.

MuRooms® are supplied with durable internal and external finishes suitable for a laboratory environment. A selection of standard cladding colors, flooring and trim options is available, depending on the room configuration and material availability.

Alternative finishes may be considered where practical, but the available choice is limited by the need to use materials that are suitable for the MuRoom® construction and magnetically controlled environment.

The selected finishes are agreed during the design process before manufacture begins.

Yes. Our standard MuRooms® can be configured with different door positions, handing and opening directions to suit the laboratory layout and access requirements.

The standard door size is determined by the selected MuRoom® model. If a different door size or a more specialized door arrangement is required, the room would normally be treated as a custom design.

Because the door forms a critical part of the magnetic shielding system, its configuration must be agreed before manufacture. Equipment dimensions and the available opening space should therefore be considered at an early stage.

MuRooms use separate service panels containing the required cable entries, feedthroughs and other penetrations. These panels are available with different feedthrough configurations and opening sizes to suit power, data, optical fibers and other experimental services.

For standard MuRooms, the feedthrough arrangement can be selected from the available panel positions and configured to meet the project requirements. If feedthrough panels need to be added or positioned in entirely different locations, the MuRoom would normally require a custom design.

The required services, cable quantities and connector sizes should be identified before manufacture so that the appropriate panels and feedthroughs can be incorporated.

MuRooms® are supplied with shielded ventilation feedthroughs that terminate in standard-sized connection tubes. These can be connected to the customer’s HVAC system, provided suitable isolation is installed between the MuRoom® connection and the building ductwork.

Internal lighting uses specially qualified LED fittings suitable for the magnetically controlled environment. Standard, dimmable and color-changing lighting options are available.

Power, data and other experimental services are incorporated through the selected service and feedthrough panels. A suitable grounding arrangement must be provided for the MuRoom®, while avoiding unintended electrical contact through building steelwork, HVAC ductwork or other services.

All requirements should be identified during the design stage so that the appropriate connections and isolation can be included.

Degaussing—sometimes called demagnetization—is a controlled process used to reduce remanent magnetism within the MuRoom®’s high-permeability shielding layers. It applies a decreasing alternating magnetic field through cables incorporated into the room, helping to reduce the residual static magnetic field within the measurement area.

Whether degaussing is required, and how frequently it should be performed, depends on the application and the required residual field. For some rooms, occasional degaussing may be sufficient. For higher-performance applications, including certain OPM-MEG systems, degaussing may be required after every door-opening cycle.

The appropriate degaussing system and operating procedure are therefore determined by the MuRoom® specification, field requirements and intended use.

Active coil compensation uses magnetic field sensors and electromagnetic coils to counteract residual and changing magnetic fields within the MuRoom®. Depending on the system configuration, it can compensate defined field components or respond dynamically to variations in the magnetic environment.

It can be used to further reduce residual fields and field gradients, particularly where exceptionally low and stable magnetic conditions are required. This can be important for demanding applications such as OPM-MEG, especially studies involving movement within the measurement area.

Not every MuRoom® requires active compensation. Whether it is needed depends on the equipment, required field level and gradients, measurement volume, surrounding magnetic environment and type of study. The requirement should be considered during the initial room specification because the coil system must be designed and integrated around the MuRoom® and its intended use.

MuRoom® performance is tested after installation and degaussing using calibrated magnetic measurement equipment. Measurements are taken within an agreed measurement volume to determine the residual static magnetic field and the shielding factor at specified frequencies.

The test method, measurement positions, frequencies and acceptance criteria are defined for the project before manufacture. Where active coil compensation is included, the passive room is tested first and the active system is then commissioned and evaluated separately.

The results are documented in a commissioning report, providing a record of the completed MuRoom®’s measured performance under the site conditions present at the time of testing.

Typical installation periods for our standard MuRoom® range are:

 Custom MuRoom® installations vary considerably depending on their size, construction and complexity. Installation may take as little as two weeks for a small specialist enclosure or, for exceptionally large and complex projects, be delivered in phases over a period of up to two years.

Installation times are estimates and may be affected by site access, available working and staging space, service integration and other project-specific requirements. A detailed installation schedule is agreed during project planning.

The installation area must have a level floor capable of supporting the completed MuRoom®, together with sufficient ceiling height and clearance around the room for assembly. Additional nearby space is required for staging, unpacking and preparing components during installation.

A suitable delivery route is also required from the unloading area to the installation location. Doorways, corridors, elevators and loading facilities should be assessed, particularly for installations on upper floors.

The proposed location should be evaluated for magnetic interference and vibration from nearby equipment, building services, elevators, traffic and other sources. The customer must also provide the required electrical supplies, a suitable grounding arrangement and isolated connections to building services such as HVAC.

Magnetic Shields can undertake a site survey to assess the proposed location, installation space, delivery route and surrounding magnetic environment. The precise requirements for each project are confirmed through the site survey, drawings and information provided during project planning.