Abstract
We report on the first experimental results obtained with a newly designed instrument for high-resolution soft X-ray spectroscopy, using reflection zone plates (RZPs) on a spherical substrate. The spectrometer was tested with a fluorescence source. High-resolution flat field spectra within ±50% around the design energies were measured at an interval of 150–750 eV, using only two RZPs: the first RZP, with its design energy of 277 eV, covered the band of 150–370 eV, and the second RZP, with a design energy of 459 eV, covered the band of 350–750 eV, where the upper boundary of this energy range was defined by the Ni coating of the RZPs. The absolute quantum efficiency of the spectrometer, including the optical element and the detector, was, on average, above 10%, and reached 20% at the designed energies of the RZPs. The resolving power E/∆E exceeded 600 for energies E inside the core range of 200–550 eV.
Highlights
With the advent of novel soft X-ray sources that provide noticeably short pulses, the need for their temporal resolution in ultra-fast spectroscopy has been emerging rapidly over the past 10 years.Besides synchrotrons and free-electron lasers, relatively small state-of-the-art systems on the laboratory scale are capable of producing femtosecond pulses, and the accessibility to a wide range of photon energies from regions near, or even below, the water window within (0.28–0.53) keV to about 1 keV could be verified in experiments.In contrast to large facilities like the X-ray free-electron laser (XFEL), with an emission up to~20 keV at an average rate >1012 photons per pulse, compact sources for the laboratory fall short of that number of photons—by orders of magnitude
±50% around the design energies were measured at an interval of 150–750 eV, using only two reflection zone plates (RZPs): the first RZP, with its design energy of 277 eV, covered the band of 150–370 eV, and the second RZP, with a design energy of 459 eV, covered the band of 350–750 eV, where the upper boundary of this energy range was defined by the Ni coating of the RZPs
Further development led to a “holographic” varied line space grating (VLSG), the off-axis reflection zone plate (RZP) that integrates two-dimensional focusing and wavelength dispersion in a single diffractive optical element
Summary
With the advent of novel soft X-ray sources that provide noticeably short pulses, the need for their temporal resolution in ultra-fast spectroscopy has been emerging rapidly over the past 10 years. ~20 keV at an average rate >1012 photons per pulse, compact sources for the laboratory fall short of that number of photons—by orders of magnitude. To maintain both the spatiotemporal pattern of the pulses and a sufficient count rate on the detector of the spectrometer, the efficiency of the optical components plays a crucial role. Beyond ~0.2 keV, the varied line space grating (VLSG) proved as a valuable device for soft X-ray spectrometry in the past [1]. Manifold experiments demonstrated the appropriateness of this approach and good performance, especially in the domain of time-resolved measurements on ultra-short pulses [2]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
