Engineering topics

Hanss, R. E.

Publications and source records attributed to Hanss, R. E..

2 records

NASA NTRS1979

X-ray diffraction studies of shocked lunar analogs

The X-ray diffraction experiments on shocked rock and mineral analogs of particular significance to lunar geology are described. Materials naturally shocked by meteorite impact, nuclear-shocked, or artificially shocked in a flat plate accelerator were utilized. Four areas were outlined for investigation: powder diffractometer studies of shocked single crystal silicate minerals (quartz, orthoclase, oligoclase, pyroxene), powder diffractometer studies of shocked polycrystalline monomineralic samples (dunite), Debye-Scherrer studies of single grains of shocked granodiorite, and powder diffractometer studies of shocked whole rock samples. Quantitative interpretation of peak shock pressures experienced by materials found in lunar or terrestrial impact structures is presented.

Hanss, R. E.↗

NASA NTRS1978

X-ray diffractometer studies of shocked materials

This study explores the utility of X-ray diffractometer scans for determination of shock pressure histories of geological materials from meteorite impact sites. The technique is based on quantification of increased crystal lattice disorder with increasing shock pressure as expressed by decreasing diffraction peak amplitude and pronounced line-broadening caused by decreasing mosaic domain size and increasing strain. The ratio of peak height (PH) to half width (HW) decreases systematically with increasing shock pressure. Data are given for experimentally shocked quartz, feldspars, pyroxene and olivine along with data for granitic materials from the Piledriver nuclear event and from the Ries Crater, Germany. Although the technique in principle may be capable of yielding relatively accurate pressure determinations, its application to naturally shocked materials may be severely limited.

Hanss, R. E.↗