MRI shielding：

The magnetic resonance shielding chamber is used to shield the magnetic field of permanent magnet and superconducting nuclear magnetic resonance equipment to prevent the external electromagnetic field from interfering with the normal work of the nuclear magnetic resonance scanning imager (MRI), and to prevent the magnetic field leakage generated by MRI from affecting the work of the external equipment.

Construction technology of nuclear magnetic resonance shielding machine room:

1.Structure: MRI type shielding chamber is designed with two kinds of structure: assembling type and welding type.

2.welding process: 0.5mm copper plate for RF shielding layer, welding using argon arc welding or brazing, high permeability steel plate for magnetic shielding layer.

3.the dragon skeleton support using aluminum alloy, and insulation treatment with the wall. Manually lock screen door with detachable beryllium green finger type copper reed.

4.high performance shielding observation window double-layer copper mesh by special process, good light transmittance.

5.other: power filter, signal conversion board, air supply and ventilation system shield excuse processing, coaxial connector, optical fiber conversion box, medical gas wave guide interface, gas fire cutoff wave guide, ECG monitoring system excuse or other medical equipment excuse and indoor lighting.

Design of nuclear magnetic shielding chamber:

The service life of the shielding body is 20-30 years. The seismic grade of the shielding shell is calculated according to the 8 grade. Considering the influence of the magnetic field and the convenience of disassembly, the copper plate assembly design is adopted.

1.Bottom surface design: The trench requirement of the shielded chamber at the position of the NMR instrument is: 2.8m×2.8m×0.9m. The depth of other parts of the room is: 55cm, and 30cm below the level is poured with C25 concrete. The pouring foundation cement mortar is ground, the double SBS waterproof treatment is carried out, the laying is made of mild insulating floor, and then the shielding body ground is made.

2.shell design: the shielding body is made of 0.35mm copper plate and high quality pine frame (brush fire paint) assembled structure. Multi-layer copper mesh gaskets are clamped between the assembled modules, which are fastened by M6x100 stainless steel screw bolts.

3.the design of the door: manual single open shield door, size: 1200mm(width)*2100mm(height) Outer open type: according to the field characteristics of the shielding room, using a single open shield door. The shielding door is the most important part that affects the shielding effect of the whole shielding chamber, the weakest part that keeps the overall performance of the shielding system from degradation, and the only movable part in the system. Therefore, it is particularly important to maintain the stability of the shielding effect of the shielding door. The structure of the door is single open type, the door plate is made of copper plate, wooden keel and stainless steel frame welding, the edge of the door frame is sealed by finger-type beryllium bronze shrapnel, using non-magnetic lock.

4.Observation window design: Observation window is double shielded glass lined with 30 mesh copper mesh, the distance between the double shielded copper mesh is 5-6 cm, to improve the shielding efficiency and ensure high definition.