X-ray performance of the LAMAR protoflight mirror

A grazing incidence x-ray mirror in the Kirkpatrick-Baez geometry was constructed and tested. Its geometric aperture measures 20 by 30 cm and its length is 100 cm. The focal length is 3.4 m measured from the front to the focal plane. It is the first of eight mirrors to be built for the LAMAR experiment of the Shuttle High Energy Astrophysics Laboratory. Its angular resolution was measured at 1.5 and 6.4 keV in a quasiparallel x-ray beam at the Marshall Space Flight Center. The half-power width (HPW) of the resolution function projected along a horizontal axis is 31 sec of arc at both energies and in visible light. With the addition of small isolation pads the mirror is able to withstand the vibration and acceleration levels of a Space Shuttle launch. The resolution remains under 35-sec of arc HPW for changes in temperature of 9.5 degrees C and when a modest temperature gradient is imposed on the mirror.