A New Sputtering Apparatus

The writer, in sputtering a large number of mirrors, has found that the apparatus and methods to be described have several advantages, particularly where very large and perfect mirrors are desired. The accompanying diagram will be self explanatory, and the dimensions given have been found convenient for mirrors up to 10 cm diameter. The apparatus has been designed to avoid the use of any grease or .wax, except shellac, which is not objectionable, and which is used wherever a cement is necessary. The sputtering chamber consists of a large bottle from which the bottom has been cut with a hot wire, the irregular rim being ground flat with moderately fine emery. The ground rim should not exceed 3 mm in width and may be bevelled down to this dimension if necessary. This rim rests on a ring of gasket rubber, 1 cm wide, which is cemented to a thick aluminum plate serving as base, as well as anode of the chamber. We are indebted to Mr. Julius Pearson of the instrument shop of this Institute for this detail of construction.