Today, we’re going to get technical: we’re talking about imaging performance of X-ray tubes; and what kind of things you need to know as a purchaser of X-ray systems, to understand what vendors are communicating to you.
X-ray Window Tubes
One of the most fundamental things to know about the design of X-ray tubes is that they’re basically light bulbs encased in a vacuum. However, on the outer part of the tube is a sort of “window” that is the aperture, or passageway, for the X-ray energy to exit the tube and enter your inspection zone.
These apertures are made from two types of materials: glass and beryllium (“Be”). Beryllium is the lightest metal in the atomic table. There are very different characteristics of X-ray tubes depending on what type of aperture sealant you have.
X-ray energy looks like a distribution bell curve. The distribution is essentially energy of photons. Let’s say you have an X-ray tube rated at 70 KV. You would, of course, have some photons with more energy, and some with less. Low energy photons are ones that are less likely to pass through something without causing the detector to see them. That includes low density things like plastic, bone, and some stones. If you’re trying to find these things, a beryllium X-ray tube is superior to a glass one because glass tubes filter out low-energy photons. That’s what glass is: a filter.
If you imagine a chicken breast with a bone in it, with a glass tube you won’t see anything; your image box would be blank. But with a beryllium tube, you’ll see that bone with clarity.
Beryllium Window Tubes
If you want to get low-energy photons, you need a beryllium photon tube. So if you’re buying an X-ray tube and you want certain types of contaminant detection, it’s really important to appreciate the value of beryllium window tubes.
They’re not offered by all manufacturers – but Peco InspX offers them with every machine that we make.
Beryllium window tubes are more expensive to make. But their performance for certain applications is superior. So if your application can use a beryllium window tube, we highly recommend that you talk to an expert about installing one in your system – because that’s going to make the difference between finding something and just having a blank image box.
If you want more helpful resources from Peco InspX visit https://www.peco-inspx.com/lp/resources