Magnetically shielded room for ebeam applications
Modern research deals with tiny structures, often even with dimensions on the atomic scale. The research instruments are particularly sensitive to any disturbances like climate changes, accoustic, vibrations, mechanical shocks and likewise magnetic fields. Therefore, magnetically protected laboratories in which such disturbances are reduced to a minimum are needed. Magnetic fields can be reduced by either passive shielding, active cancellation, or the combination of both.
With Systron LabShield®, a mu-metal based magnetic shielding system is available to shield entire rooms against static DC, slow varying DC and electromagnetic AC and DC stray fields. Those fields are emanated from magnets, moving metal objects such as cars or elevators and electrical components such as transformers, cables, distribution panels or over head high-tension power lines.
Systron individually designs the magnetically shielded rooms, based on the proven shielding system Systron LabShield®. Systron LabShield® is a magnetic shielding system designed to attenuate static DC, slow varying DC shifts and AC stray fields. Magnetically shielded rooms for ebeam applications are a safe and reliable method to protect sensitive tools, such as electron microscopes, ebeam writers or focused ion beam from unwanted electromagnetic fields.
With the Systron LabShield® series, the various room and foundation constructions are met, regardless whether the shielding needs to go under or on top of the foundations, or a room in room design is required.
LabShield® - Modular magnetic shielding system
The LabShield® series offers a full series of standardized configurations, however, they are adapted to the individual needs.
|Series Berlin||Series Zurich||Series Dresden||Series Vienna||Series Paris|
With Systron LabShield®, excellent attenuation is achieved in the slow varying DC (DC-shifts) and low AC frequency range. The excellent attenuation for the DC and low AC frequancy is achieved with the use of heat treated Nickel Iron, widely called "Mu-Metal", "Mumetal" or "Permalloy". With this Nickel iron, shielding factors can be reached that never can be reached with silcon iron, known as electrical steel, transformer steel or similar alloys. Special care must be taken when silicon iron with it's 95% iron is used for laboratory shielding applications, as silicon iron can rust easily.
Typcal annoying stray field frequencies found in electron beam rooms:
|Static field||DC, 0 Hz||Earth magnetic field|
|Slow varying DC field, near DC||0.01 Hz - 10 Hz||Tram ways, moving metal objects (cars, elevators)|
|Train||16.7 Hz||Railway systems|
|Mains||50 Hz / 60 Hz||Electrical installations, cables, bus bars, transformers, distribution panels|
|Mains||50 Hz / 60 Hz||Over head power lines|
|Ripple control||100 Hz - 1600 Hz||Electrical cables|
With Systron LabShield®, in it's standard single layer design, attenuation up to 26dB can be achieved. However, with a multi layer design much higher attenuation can be reached. The multilayer design usually includes not only magnetically conductive but often electrical conductive layers, too.
- General considerations for design and construction of transmission electron microscopy laboratories
- Measurement of magnetic field distorting the electron beam direction in scanning electron microscope
Check pictures of TEM rooms: