One embodiment of the present disclosure is directed to a mobile X-ray unit. The mobile X-ray unit may include a base and an arm associated with the base. The arm may be configured to support an X-ray applicator having an X-ray tube. The X-ray tube may be configured to generate an X-ray beam. The X-ray applicator may include an exit surface through which the X-ray beam passes in use. The X-ray unit may further include an applicator cap for covering at least the exit surface of the X-ray applicator.
