At the beginning of the run, and during the year, information sessions are held for the users that are testing during the year. If you requested beam time in CHARM, you will be invited to one of these sessions.
During the meeting, that is held online, material about CHARM facility structure, radiation fields and procedures is shared. The material can be found at the following links:
https://edms.cern.ch/document/3161916/1
https://edms.cern.ch/document/2721313/7