Accession Number : ADP008061

Title :   Low-Radiation-Damage Multilayer Coatings for the Soft X-Ray Region,

Corporate Author : SFA INC LANDOVER MD

Personal Author(s) : Hunter, W.R. ; Seely, J.F.

Report Date : 05 MAR 1992

Pagination or Media Count : 4

Abstract : Highly reflecting multilayer coatings (MLC), used to form resonant cavities for some x-ray lasers(l) in which double- and triple-pass amplification occurs, can be destroyed by strong electric fields generated at the multilayer boundaries by intense soft x-ray radiation, rather than plasma debris from which the coatings are shielded. Any multilayer coating used in high field strength applications, FEL, x-ray projection lithography, etc., are subject to such damage. Electric field strengths can be reduced at the boundaries in MLCs by altering slightly the layer thicknesses of the final, or topmost, layers. Calculations are presented showing reduced field strengths caused by altering final layer thicknesses. The optical constants used in the calculations were obtained from Henke et al(2) and Palik(3) so similar computations may vary depending on the actual n,k values used but the basic concepts discussed herein are independent of the optical constants.

Descriptors :   *COATINGS, *DAMAGE, *RADIATION, *SOFT X RAYS, *X RAY LASERS, *LOW RATE, AMPLIFICATION, BOUNDARIES, CAVITIES, CAVITY RESONATORS, COMPUTATIONS, CONSTANTS, DEBRIS, ELECTRIC FIELDS, LASERS, LAYERS, LITHOGRAPHY, VALUE, X RAYS, REFLECTIVITY, PLASMAS(PHYSICS), OPTICS, THICKNESS.

Subject Categories : Nuclear Physics & Elementary Particle Physics
      Coatings, Colorants and Finishes
      Radiation and Nuclear Chemistry
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE