X-Ray Therapy

 
In the order of formation, the first device was the therapeutic X-ray. The high-voltage is between 10 and 300 kV (can be changed), the tube current is variable between 6 - 25 mA, or fixed. This depends on the type of the device and the application. The 10 - 50 kV range is used in soft X-ray therapy, with Be-window (beryllium) tubes, using usually fixed highvoltage-filter combinations and constant current.
Another special X-ray device used in Europe is the Chaoul. It works with special anode, constant highvoltage and tube current, fixed filtration and 1,5 - 5 cm focus-skin distance. The machines operated in 50-300 kV range with different filtering are called orthovoltage or deep X-ray therapy units (focus-skin distance: 30-50 cm). Their importance is strongly reduced in nowadays.

X-ray therapy units used in surface and deep therapy