The absorption coefficient spectrum of poly(methyl methacrylate) in the soft X-ray region

The total photoabsorption cross section for poly(methyl methacrylate) (PMMA) is measured experimentally, using synchrotron radiation, over the photon energy range 40 < E < 1000 eV. The experiments utilize nominally monochromatic radiation from a grazing incidence grating monochromator (the “Grasshopper” at the Canadian Synchrotron Radiation Facility) on the storage ring “Aladdin” at the University of Wisconsin. The raw experimental data are corrected for the spectral contamination of the incident radiation from the monochromator by utilizing a calculated photoabsorption spectrum for PMMA. The calculations are carried out using the “mixture” rule and reliable dipole oscillator strength distributions for smaller molecules related to PMMA.