The Johns Hopkins University rocket group is seeking to develop a hydrogen absorption cell to act as narrowband H I Lyα rejection filters for ultraviolet solar blind imaging detectors. A heated tungsten filament in the cell produces free atomic hydrogen by dissociation of molecular hydrogen contained in the cell. This creates a gas that is optically thick to the Lyα , effectively filtering out incident geo-coronal Lyα emission. This suppression of geo-coronal light will in principle make possible imaging observations of astrophysical sources into the far-UV below 1200 Å, down to the lithium-fluoride transmission edge near 1040Å. The flux attenuation of a hydrogen cell has been measured in a vacuum monochrometer testbed. The goal is to produce a usable hydrogen cell design that can be easily mounted on a detector for photometric observations of astronomical sources in the far-UV.

Date Published: 26 September 2013
PDF: 5 pages
Proc. SPIE 8859, UV, X-Ray, and Gamma-Ray Space Instrumentation for Astronomy XVIII, 88590P (26 September 2013); doi: 10.1117/12.2024346

Published in SPIE Proceedings Vol. 8859:
UV, X-Ray, and Gamma-Ray Space Instrumentation for Astronomy XVIII
Oswald H. Siegmund, Editor(s)