Good morning!
I would like to know if a 20 years unused x-ray tube inserted in a mobile radiography unit can produce x-ray?

 

Sure. If the mobile radiography unit is designed to use that 20 years old x-ray tube or one very similar to it.

 

Sure. If the mobile radiography unit is designed to use that 20 years old x-ray tube or one very similar to it.

Even the tube was not used for very long time?

 

Even the tube was not used for very long time?

It's a vacuum tube. What's the tube number/model? Most of the time there is a getter to remove the last of residual air after the neck is sealed. If it's bright and shiny, likely the tube still has good vacuum with little or no use, if it's rainbow, had use (sometimes abuse) but likely is still good, if it's white and milky, it's junk. You can check the filament condition with a ohmmeter on the pins to see it there is continuity. If it's open, it's junk.


Bad vs Good

Rainbow getter on a used tube.