The selection of shielding materials for photomultiplier tubes mainly depends on the type of interference that needs to be shielded (such as light, electricity, magnetism, etc.). The following is a clear analysis and summary of the shielding materials for photomultiplier tubes based on the information provided in the reference article:

Light shielding materials

For the shielding of optical signals, it is usually necessary to use materials that can penetrate the target wavelength but block other light rays.
Borosilicate glass: When applied in the visible to near-infrared bands, borosilicate glass is a commonly used incident window material because it can transmit light in these bands.
Transparent ultraviolet glass (UV glass), synthetic quartz glass, and magnesium fluoride (or magnesium fluoride) glass: When photomultiplier tubes are applied in the ultraviolet region, these materials are used due to their good transmittance to ultraviolet light.

Electrical shielding materials

The shielding of electricity is mainly to eliminate or reduce the influence of electric fields on electron beams.
Conductive materials, such as copper foil, conductive foam, etc., have good conductivity and can effectively eliminate electric field interference.
Nano lanthanum hexaborate and metallic nickel powder: These materials can also be used as electromagnetic shielding materials to eliminate electric field interference through their conductivity.

Magnetic shielding materials

Magnetic shielding is used to protect photomultiplier tubes from magnetic field interference.
High permeability ferromagnetic materials, such as electrical pure iron, silicon steel sheets, iron nickel alloys (such as permalloy), etc., have high magnetic permeability and can effectively shield external magnetic fields.
Aluminum alloy casing: In addition to using high magnetic permeability materials, aluminum alloy casing can also be used to seal the photomultiplier tube, further improving the magnetic shielding effect.

To summarize the above:

Light shielding: mainly using glass materials that have good transmittance to target wavelength light.
Electrical shielding: mainly using materials with good conductivity, such as copper foil, conductive foam, etc.
Magnetic shielding: It mainly uses high permeability ferromagnetic materials, such as electrical pure iron, silicon steel sheets, iron nickel alloys, etc., and can be used in conjunction with aluminum alloy shells to improve the shielding effect.



In practical applications, according to the types of interference and working environment faced by photomultiplier tubes, the above-mentioned materials can be flexibly selected and used for shielding design. At the same time, in order to ensure the shielding effect, it is necessary to design and layout the shielding structure reasonably.