| 摘要 |
PURPOSE:To make the thickness of the part, through which a radioactive ray transmits, as thin as possible and to facilitate its attachment to a protective case. CONSTITUTION:A region of a thin titanium (Ti) 11 with a diameter of 50mm. is to be corroded. Regions of the titanium other than said region, i.e. a part of an upper surface 11a, the entire region of a lower surface 11b, and an outer surface 11c are coated by wax, and a wax layer 12 is formed. Then the thin plate 11 is immersed in an etching liquid of hydrofluoric acid + water (1:1) for a specified time. Thereafter the plate 11 is washed by water. Then the part of the titanium, which is not coated by the wax layer 12 that is a mask, is corroded to a uniform depth, and a concave part 13 is formed. The thickness (t) at said part becomes thin. The corrosion by the etching and washing by the water are repeated, and the thickness of the thin film of the titanium is made to be about 10mum. Then the plate is immersed in the wax solvent and the wax layer 12 is removed. Thus a detecting window 14 whose thickness is 10mum and a window frame 15 are formed. |
