Development of a wideband multilayer grating with a new layer structure for a flat-field spectrometer attached to transmission electron microscopes in the 2-4 keV range
Imazono, Takashi; Koike, Masato
A soft X-ray spectrograph to attach to electron microscopes has been developed. Original TEM-SXES instruments can detect soft X-ray emission (SXE) spectra of the 60-2000 eV range. However it is necessary to develop a new SXES instrument that covers a much wider energy range. It is of importance to detect the SXE spectra from 2 keV to 4 keV. Observation of the SXE spectra in this energy range needs a multilayer grating because in which a typical grating with the gold coating is no longer practical. A conventional multilayer grating has high diffraction efficiency but narrow band at a fixed angle of incidence. It indicates that the SXES instrument should employ a mechanism for wavelength scanning to cover the required energy range and is unsuitable for the spectrograph to attach to a TEM. To overcome this problem, we have invented a new multilayer structure to uniformly enhance the reflectivity in a few keV energy range at a fixed angle of incidence.