LIGHT INTENSITY MEASURING APPARATUS

摘要

PURPOSE:To enable measurement of intensity of light in a wide range of wavelength area by reducing an exhaust conductance of a cell with both ends thereof opened by more than two digits in comparison with an exhaust conductance of a vacuum container. CONSTITUTION:A vacuum container 8 and exhausting sections 9 and 10 are exhausted with a vacuum pump. A gas cell 7 with an electrode has an exhaust conductance lower more than two digit in comparison with an exhaust rate of the container 8 and a vacuum of the container 8 is made higher by more than two digits in comparison with that of the cell 7. Single pipes 11 and 12 have an exhaust conductance smaller more than two digit in comparison with amounts of exhaust of exhausting sections 9 and 10 and a vacuum of the exhausting sections 9 and 10 is made higher by more than two digits in comparison with that of the container 8. Then, a photomultiplier 13 for vacuum ultraviolet rays is mounted behind the container 8 and a rare gas is introduced into the cell 7 to measure absorption of a monochromatic light with a specified wavelength thereby accomplishing a measurement of a gas pressure in the cell 7. Thus, the use of a gas with a light ionization sectional area known per wavelength enables the measuring of intensity of white color such as radiation light.