Efficiency calibration of the first multilayer-coated holographic ion-etched flight grating for a sounding rocket high-resolution spectrometer.

We have fabricated the four flight gratings for a sounding rocket high-resolution spectrometer using a holographic ion-etching technique. The gratings are spherical (4000-mm radius of curvature), large (160 mm x 90 mm), and have a laminar groove profile of high density (3600 grooves/mm). They have been coated with a high-reflectance multilayer of Mo/Si.

Optimization of layered synthetic microstructures for broadband reflectivity at soft x-ray and EUV wavelengths.

A technique is described which allows the thickness of each layer in a layered synthetic microstructure to yield a useful constant efficiency over a broad band of wavelengths, several hundred angstroms wide, in the soft x-ray and EUV wave bands.

Apollo 16 Geochemical X-ray Fluorescence Experiment: Preliminary Report.

The lunar surface was mapped with respect to magnesium, aluminum, and silicon as aluminum/ silicon and magnesium/ silicon intensity ratios along the projected ground tracks swept out by the orbiting Apollo 16 spacecraft. The results confirm the observations made during the Apollo 15 flight and provide new data for a number of features not covered before. The data are consistent with the idea that the moon has a widespread differentiated crust (the highlands).

X-ray Structure of the Cygnus Loop.

X-ray emission from the Cygnus Loop was observed in the energy region around 0.2 to 1 kiloelectronvolt with a collector that focused x-rays along one dimension while scanning across the nebula. The total integrated intensity is 1.