For soft X-ray radiometry source and detector standards are required. Changchun lnstitute of Optics and Fine Mechanics supports a research and development program in the vacuum ultraviolet and soft X-ray region of the spectrum with the goal of providing radiometric source and detector standards for measurement applications. The primary standard used in these calibrations is a rare gas ionization chamber. Calibrated Al

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diodes are available as transfer detector standards with a calibration uncertainty of ?6%.