Usage Conditions May Apply Usage Conditions Apply There are restrictions for re-using this media. For more information, visit the Smithsonian's Terms of Use page. IIIF provides researchers rich metadata and image viewing options for comparison of works across cultural heritage collections. More - https://iiif.si.edu View Manifest View in Mirador Viewer

One of a set of specialized ultraviolet detectors in the collection. These channeltron tubes are typical of those used in the Orbiting Solar Observatories (OSO) project in the early space program. These tubes were used to convert and amplify ultraviolet radiation into electrical signals that could then be telemetered back to earth for further study. The design of these Bendix tubes is based on a similar principle to the photomultiplier tubes used to convert visible light into electric signals. This example is equipped with an attached preamplifier circuit. It was transferred to NASM in 1988 by NASA (GSFC). It is now stored at the Garber Facility.

This channeltron consists of a hollow curved tube of semiconductive glass sealed at both ends. When a photon strikes the inner surface of the evacuated tube it causes additional electrons to be released from the surface. The electric potential that is set up between the ends of the tube by an applied voltage accelerates those electrons towards the other end of the tube. These release additional electrons each time they strike the walls. The resulting cascade of charges has the net effect of greatly amplifying the signal from the initial ultraviolet photon. The total signal is collected by the anode at the end of the tube for further processing. The channeltron is curved to prevent backscatter of charge from ions that may result from ionization of residual gas molecules in the evacuated tube.

Display Status

This object is not on display at the National Air and Space Museum. It is either on loan or in storage.

Object Details
Country of Origin United States of America Type INSTRUMENTS-Scientific Manufacturer Bendix Corp.
Dimensions 3-D (Board): 7.1 × 6.3 × 1cm (2 13/16 × 2 1/2 × 3/8 in.)
2-D - Unframed (H x W) (Paper): 8.9 × 6.5cm (3 1/2 × 2 9/16 in.)
Materials Plastic
Glass
Copper Alloy
Paper
Inventory Number A19880221000 Credit Line Transferred from the National Aeronautics and Space Administration Data Source National Air and Space Museum Restrictions & Rights Usage conditions apply
For more information, visit the Smithsonians Terms of Use.