a mount for attaching an electrode system , which focusses electrons generated upon the incidence of x - rays on an input luminescent screen onto an output luminescent screen , to an exterior housing of the intensifier is formed by annular electrodes which telescopically engage and which are held together at overlapping regions by a clamped connection . the mount has a simple structure which minimizes the possibility of the electrode system getting out of adjustment , and also significantly decreases the assembly time during manufacture of the x - ray image intensifier .