Development of X-ray optics for the solar flare sounding rocket FOXSI-4: ground calibration

We have been developing X-ray optics for a fourth FOXSI (Focusing Optics X-ray Solar Imager) sounding rocket experiment, FOXSI-4. We fabricated two types of X-ray optics specified for soft and hard X-ray observations and finally evaluated environmental tolerance required such as random vibration. Additionally, we conducted X-ray irradiation tests at 2-18 keV using a large area beam to evaluate X-ray performances such as FWHM, HPD (Half Power Diameter), and effective area. Consequently, we obtained <5 / <3 arcsec (detection limit) in FWHM, ~16 / ~20 arcsec in HPD and ~18 / ~41 mm^2 in on-axis effective area for both soft and hard X-ray optics, respectively. Additionally, we constructed our original ray-tracing simulator and confirmed that the resultant energy dependence of the effective area is consistent with the expected values. We will report the details and the latest status of our optics.