A Calibration Facility for Soft X-ray Missions

This project is to extend the capabilities of the Extreme Ultraviolet Calibration Facility in the Goddard Space Flight Center (GSFC) Heliophysics Science Division (HSD), which can currently provide radiometric calibration, wavelength calibration, and spectral resolution measurements at wavelengths down to 25 nm, to include the Soft X-ray region from 0.12 to 25 nm (0.05 to 10 KeV) as well.

The objective of this task is to provide a calibration and test facility for missions to observe the soft X-ray region of the spectrum, specifically, in the wavelength range 0.12-25 nm.  This provides additional capability beyond the current capability of the existing HSD facility in the Extreme/Vacuum Ultraviolet (EUV/VUV) wavelength range 25-200 nm.  Thus, the result will be a facility at GSFC to provide comprehensive coverage of the wavelength range 0.12-200 nm, with the capability to measure radiometric response, wavelength scale/response, and spectral resolution of high-resolution spectroscopic and imaging instruments for this wavelength range. A soft X-ray filament ("Manson") source has been obtained to produce emission lines in the 0.12-25 nm wavelength range.  A set of anodes for the source provide a multitude of characteristic lines from K, L and M-shell transitions, as well as bremsstrahlung continua, at X-ray energies up to 10 KeV.  This IRAD will modify the HSD EUV calibration facility to incorporate this new soft X-ray source, and will plan and execute a calibration using this new source, with NIST traceability provided by a NIST-calibrated silicon photodiode.