I have asked several tech people in the x-ray equipment field and not yet gotten a satisfactory answer to this question- perhaps someone here can enlighten me. When an x-ray source is behind a shield can it be safely viewed with a mirror (e.g., are the x-rays absorbed by the glass or to they reflect from the front surface of the glass)? DATA: Mirror is 1/4-inch thick, common borosilicate glass, "silvered" on the back surface. Angle of incidence is 45 degrees. X-ray energy is the copper K-alpha emmission line, (wavelength=1.54 angstroms= 1.54*10e-10 meters), (energy= 8.04 Kev= 1.29*10e-15 joules). -Bill Morrow