Hi, (I'm not native in English, sorry for if bad English) Some background: As a programmer I got more and more distance with physics. I bought a US x-ray tube off ebay to step to a hobby project that naturally keeps me on with refreshing physics knowledge. After the tube came, I jumped into internet and hit head to an article about Edison's assistant's cancer out of x-ray. The fear of 'making health problems' introduced a huge force vector in negative direction and I stayed blocked with my project for 1 year (till now). Well, fear is no good. Newly I finished a small robot that could be directed from internet, by wifi. I now can use that in my initial x-ray project and not be presented where x-ray is active. I need to know for safety: 1. how far the device must be from me 2. how long should I not to enter the place after x-ray photography 3. what best / cheapest measurement instruments I must buy to study the environment (I'd like to obtain 2 instruments from 2 different producers, put in the environment and fix a web camera on them, then read before entering the place). realization: 1. where can I get information to first test the tube I bought and know if it is alive 2. what is the best schematics to put the tube to work. I would appreciate your kind help in pointing to articles, tutorials online and suggestions / answers for above questions.