An embodiment of a gamma ray generator includes a neutron generator and a moderator. A chamber part may then be rinsed, ultrasonically cleaned in a ultrasonic cleaning liquid, and then rinsed again with a liquid that may evaporate at a lower temperature than an ultrasonic cleaning liquid. Each latching element comprises a plurality of protrusions and a detaching means. The enclosure includes a replaceable top portion which includes a phosphor portion.