Requirements for Enclosed Beam X-ray Systems

An enclosed beam system is a system in which all possible x-ray paths are fully enclosed so that any part of the body cannot enter the enclosure. In addition to the general requirements found in paragraph 2 above, the following requirements must be met:

a. Safety Devices

There must be:

• Enough interlocks to prevent the generation of x-rays or the emergence of the primary beam when any section of the enclosure is opened during routine operation, alignment or maintenance.
• A chamber or coupled chambers enclosing the radiation source, sample, detector and analyzing crystal, which cannot be entered by any part of the body during normal operation.
• A sample chamber closure with a fail-safe interlock so that no x-ray beam can enter an open sample chamber.

b. Dose Limits

The equipment must be so constructed that the dose rate due to leakage radiation at 5 cm from any accessible surface does not exceed 0.25 mrem/hour during normal operation.