This is the type of X-ray machine used by Brent Seales, mentioned in the article "Reading Buried History". Normally, it is used to examine human beings, but he's using it to try and read ancient scrolls that were buried when Mt. Vesuvius erupted.
I had a CT exam a few months ago. I had to lay down on the "bed", and they elevated it, then slid the bed into the hole of the "doughnut". It wasn't bad, only seven or eight minutes. Much less stressful than an MRI exam (which I also had, and lasted an hour---ugh!).
