X-Ray Phosphor Screens for Industrial Inspection
X-ray phosphor screens for industrial inspection
X-ray phosphor screens for industrial inspectionX-ray phosphor screens for industrial inspection are the coated component that makes an X-ray image visible. The phosphor layer absorbs X-ray energy and re-emits it as visible light, which the camera or sensor behind it records. Without the screen there is nothing for the sensor to see, which is why the coating specification has such a direct effect on the quality of the image you end up inspecting.
At Analytical Components we coat these screens to order in our Class 10,000 (ISO 7) cleanroom in St Leonards on Sea. We are ISO 9001:2015 accredited, and we build screens to a customer specification rather than to a standard part list.
What the screen does in an inspection system
X-rays leave the source, pass through the part being inspected and land on the phosphor screen. Denser material in the part absorbs more of the beam, so the amount of X-ray energy reaching each point on the screen varies. The phosphor converts that pattern into visible light, and a silicon sensor such as a CCD or CMOS detector turns the light into an image. Voids, cracks, inclusions and foreign objects show up as differences in brightness.
For X-ray work, the phosphor we coat most often is P43, gadolinium oxysulfide, also written Gd2O2S, Gadox or GOS. Its emission sits at wavelengths silicon sensors read efficiently, its behaviour is well documented, and it converts X-ray energy to light comparatively efficiently. It comes in three formulations.
- Gd2O2S:Tb emits yellow green light peaking at 545nm, with medium persistence and low afterglow.
- Gd2O2S:Pr emits green light at 513nm, decays to 10% in around 7 microseconds and shows no afterglow.
- Gd2O2S:Eu emits red light at 627nm and suits the highest beam energies.
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Coating thickness and particle size set your image quality
This is the part of the specification that most affects what you see, and it is where we spend the most time with customers. We can supply coating thicknesses of a few microns up to a few hundred, and particle sizes between 1.5 and 25 microns.
Smaller particles give higher resolution, which is what you want when you are looking for fine cracks or small inclusions. Larger particles give more brightness and better conversion efficiency, which helps when the beam is weak, the exposure is short or the line is moving quickly. There is no single correct answer, only the sensible trade-off for the defect you need to catch, and it is worth setting that deliberately rather than carrying over the specification of the previous screen.
Substrates and optional layers
We coat onto float glass and other glass types, fibre optic plates (FOPs), silicon, and flexible materials such as Mylar. For X-ray phosphor screens for industrial inspection we can also coat onto metals including stainless steel, copper and aluminium, which is often the practical choice where a screen is mounted in equipment that gets handled or cleaned.
Where the instrument needs an electrical connection to the screen, dielectric substrates such as FOPs and float glass can be given a conductive indium tin oxide (ITO) undercoat. Other optional layers, including aluminium overlays for electron beam work, are covered on our phosphor screen scintillators page.
Durability in a working environment
Phosphor screens are easily damaged, and the lightest touch can be enough to mark a coating. In a production setting, where screens are installed, adjusted and cleaned as part of routine work, replacements add up. We can coat screens using a potassium silicate process, known as waterglass, which improves the durability of the phosphor layer and its resistance to handling damage. If your screens are being replaced more often than you would like, this is worth asking us about.
Why choose Analytical Components
We are a manufacturer, not a reseller, and we deal with customers directly. That means you can speak to us directly about how your screen will be made, and we would rather work through a specification carefully than send out something that almost fits.
You can have progress updates by phone or email while your order is in production, and you are welcome to visit the facility, which we encourage. We treat customer confidentiality as a priority and offer NDAs where they apply.
Analytical Components is ISO 9001:2015 accredited, meaning we have demonstrated that we can consistently supply products meeting customer and regulatory requirements. The standards we hold in our cleanroom and in our raw material selection are what keep the coating process and the finished screens uniform, whether the order is a batch or a single piece.
Our ISO 9001:2015 certificate, RoHS and REACH documentation are available on our downloads page, and you can read more about Analytical Components.
Talk to us about X-ray phosphor screens for industrial inspection
If you need X-ray phosphor screens for industrial inspection, for security equipment or for use as energy detectors, tell us what the screen has to do and we will specify it with you. Fill in our contact form, email info@analyticalcomponents.uk, or call +44 (0) 1424 850004. Useful things to have to hand are the screen dimensions, the substrate, the sensor type and the smallest defect you need to resolve.
X-ray phosphor screens are used wherever an X-ray image needs to be made visible. In medical imaging, dental imaging and veterinary imaging they give clinicians the detail needed for accurate diagnosis. They are used in security screening for reliable detection, in industrial inspection to protect product integrity and safety, and in imaging cameras.