h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

after the x ray tube takes a voltage it will produce light energy not heat energy as you hace said this light energy will be collected by photo diode which will convert the light signal into electronics current it will then be processed vy the video board etc. so not heat enery but light.

Traveller in Time X-ray technician
"The entry states:
>>X-Rays are produced by converting electrical energy into an electromagnetic wave. This is done by accelerating electrons from an electrically negative cathode towards a positive 'target' anode. When the electrons hit the target they are decelerated rapidly, causing them to lose energy which is converted into heat energy and X-Rays. The anode and cathode effectively form a circuit which is completed by the flow of electrons through the vacuum of the tube.


It happens the material for the Anode is not chosen at random. One of the properties of Tungsten is the emission of X-rays (only between certain angles 'Heeling effect') when bombarded with electrons. Other materials will produce light (Phosphor as used in screens for display) or UltraViolet (Neon, Mercury). "

>>>causing them to lose energy which is converted into heat energy and X-Rays<<<

So it produces both 'light' and heat

Dear friends,

I found this entry extremely interesting.

Thank goodness I did not have to learn it all when I was studying to become a radiographer way back in 1947-1949. Training to be a radiographer in those days was a two year course, and at the end of it we earned membership of the British Society of Radiographers.

Looking back on it now I realise what wonderful work Marie Curie did. It was she who found out that the "pitchblend" which she and her husband Pierre were studying was the material which made her "hand" when held up against on a photographic plate which apparently was "accidentally" near to some pitchblend which she and her husband were studying, demonstrated,for the first time, the bony structure of her hand I seem to remember that it was at the end of the First WW, in about 1917.

It was a truly wonderful discovery.

However, it would have been very nice if you had also said that the radiographers(not only the patients!!) were also exposed to the very dangerous X-ray emissions which came - I believe or seem to remember - from the emissions from the rotating anode flinging X rays all around the room. We, the radiographers, were always supposed to wear lead aprons in order to protect us, and also lead gloves. But if there was a shortage it was invariably the radiologist who had first option. !!

I often wonder if the problems I still have with my skin and my hands are due to over exposure to X rays when I was young.

All the screening of patients was done in the pitch dark as was the development of the X ray films/plates. Actually there were a few red globes scattered around and we always had to get our eyes "accomodated " to working in the dark, by wearing red glasses for about ten minutes before we went into the particular room where there screening was being done. I always have a wry smile when I see everyone working in broad daylight now whenever there is some sort of sdreening process which has to be done.

Thank you for reminding me of my days as a student radiographer. My goodness they were very terrifying, particularly at the weekend, or when we had to go to theatre in in order to assist the orthopaedic surgeon who was repairing fractured neck of a femur by inseting a Smith-Petersen pin. The correct functioning and repair of the fracture depended on us , poor miserable radiographers, angling the X ray plate and the tube head in the very narrow confines of the lower abdominal area. This was because, we had to Xray through the pelvic girdle; I still shiver with fright when I think about it , and naturally as it was being done in the theatre where the surgeon had had to cut the skin in order to "set" the fracture and insert the S-P pin, in totally asceptic conditions.

My goodness, those were the days.

Thankyou all again for reminding me of those very exploratory days in the history of Radiography and Radiology.

Incredible how being able to undergo examination of one's ailments by means of such technology has revolutionised our whole way of living a reasonable life even after one has been badly injured, or is suffering from many of the ailments now floating around.

Christiane
AR80

The same principle is used throughout industry in electron beam welding equipment. The components to be joined form the anode and are melted very locally by the beam of electrons to form the weld. X rays are produced in the same manner but are mearly a by product of the process from which the operator must be protected; usually by the thick walls of the containment vessel. The advantage of the process over other types of welding is the deep penetration, narrow heat affected zone and cleanliness due to the process being carried out in high vacuum.