High School Science Project using a 1920 General Electric Coolidge X-ray tube

For a 1966 high school science project, my father and I made an X-ray machine using a 1920 vacuum GE Coolidge X-ray tube (shown above).   This tube was invented by William Coolidge while working for General Electric in 1913 and went into production in 1916.   You can see the GE insignia and Model # 71265 stamped on the blown glass casing toward the top.

My father was a radiologist and as a family, we grew up in a x-ray based environment.   Even our German Shepard fell prey to this.. he was named Roentgen (the man that discovered X-rays).  My father's mechanical knowledge was instrumental with this school project (also, making sure it was a safe environment). 

To create the X-ray machine we used the following:

1. A functional X-ray tube   2. a low voltage step down transformer (we used the controls from my electric train set) to adjust the Ma  3. a step up transformer (borrowed a 40,000 volt neon sign transformer) to provide the burst of energy to create the X-ray) which was the KvP.  4. lead shielding  5.  lead glass and light tight viewing goggles   6. a phosphorous screen removed from from an x-ray film cassette (this glowed when exposed to X-rays).

It was a functional X-ray machine in it's simplest form.   The cathode filament was lit and adjusted by the electric train transformer.  We installed an on/off  button attached to the neon sign transformer that created a 40,000 volt bust of energy.  When those electrons hit the stationary tungsten anode target in the Coolidge tube, it created an X-ray beam that was focused on the phosphorus screen.   While looking thru a light tight lead glass viewer, you could see the screen glow as the X-ray beam hit the phosphor.   All of this was shielded with lead and tested for safety prior to using in class. 

Later in life, I worked for DuPont Medical Products, Sterling, and Agfa Healthcare.    I have had the pleasure of transitioning from X-ray film to the world of digital imaging.   It has been exciting seeing the progress that has been made over time.