Study of large-field beryllium window for SR lithography (Poster Paper)

摘要

Abstract: The resisting pressure of deep cylindrical beryllium (Be) windows was studied theoretically and experimentally. A cylindrical Be window (window size, 50 $MUL 50 mm$+2$/; thickness, 20 $mu@m; radius, 30 mm) which was fabricated on the basis of the theoretical calculation sustained up to 0.43 MPa (pressure difference) in hydraulic pressure burst testing. Deflection of this foil was 0.2 mm at this pressure. A planar window (diameter, 38 mm; thickness, 30 $mu@m) sustained pressures in the region of 0.25 MPa to 0.49 MPa. Deflections of these foils were in the region of 0.9 mm to 1.4 mm. A deep cylindrical Be window was found to be superior to a planar one in 1 atm. (0.1 MPa) helium gas, in terms of its larger field size and higher transmittance of SR.!2