Metal Foils as Filters in the Soft X-Ray Region

Abstract

The paper describes the use of thin foils of Be, Mg, and Al as filters in the 50 to 500 A spectral region. Mention is made of various procedures for the preparation of plastic backing films. Included are illustrations which show how the metallic filters may be utilized to exclude visible light, to sort out overlapping orders, and to transmit narrow bands of radiation by reducing the intensity of undesirable portions of the spectrum. For each of the metals and for a plastic material (Zapon), plots showing the linear absorption coefficient as a function of wavelength are also given. The absorption curves facilitate the choice of the appropriate filter and its thickness.