Hi All,
Better late than never.
This may be worth a look although it isnt intended for engineers its all good background information.
http://openlearn.open.ac.uk/course/view.php?id=3318A healthy respect for radiation and high voltage is important as is a willingness to learn.
The major suppliers are the best source of training but its expensive.
I have run basic X-ray courses for ebme technicians in the past but the demand seems to have disappeared.