10.
10.1 Absolute Reflection Efficiency

Adequate data to permit empirical evaluation of the x-ray optical constants as a continuous function of energy. Must reveal all spectral features, their energies, discontinuities, and energy widths. There is no sufficiently accurate information available on the reflectivity of the AXAF mirror surfaces without these measurements. A source with the required energy resolution could not be conceived for the XRCF. The off-line nature of this experiment, done at the synchrotron, removes it from the AXAF critical path. In fact, if necessary, some of the work can be done after launch.

Accurate determination of absolute source spectra.

Every grazing angle pertinent to the HRMA. Angle intervals to be variable, with coarse spacing away from the critical angle, and fine spacing near the critical angle. Choose angle steps so the reflection efficiency changes by 5% for each step.

N.A.

Temp1, 5 °C.

10 eV

10.2 Image distribution from surface scattering

Microroughness.

Interpretation of extended source structure.

N.A.

N.A.

Temp1, 5 °C.

TBD

10.3 Contamination vs. time

Effects of contamination as a function of time and event between completion of HRMA and launch.

Estimation of changes to reflection efficiency and scattering between XRCF calibration and on-orbit operation.

N.A.

Temp1, 5 °C.

N.A.

10.4 Detector Cross-calibrations

Measure efficiency of a photometric detector at NIST

Improve confidence in absolute calibrations

N.A.

Temp1, 5 °C.

Fe-K, Al-K