A variable delay line is being developed as part of a far-infrared or submillimeter- wavelength interferometer that would operate in a vacuum in the cryogenic temperature range. No such delay line for spatial interferometry has previously been built for operation under these conditions.
The delay line includes an aluminum carriage supported on four wheels that are constrained, by a set of preloaded steel straps, to move along straight lines. The only friction that occurs in the delay line is rolling friction between different materials; this aspect of the design minimizes the risk of vacuum adhesion between parts made of similar metals. Relative to a competing design based on flex pivots, the roller design of this device affords greater robustness, stiffness, range of motion, and compactness, all with fewer parts.
This work was done by James Moore, Mark Swain, and Peter Lawson of Caltech for NASA’s Jet Propulsion Laboratory.
This Brief includes a Technical Support Package (TSP).
Variable Submillimeter-Wave Delay Line for Cryogenic Use
(reference NPO-21167) is currently available for download from the TSP library.
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Overview
The document discusses the development of a variable submillimeter-wave delay line designed for operation in cryogenic temperatures, specifically for use in far-infrared or submillimeter-wave interferometry. This innovative technology is notable because no similar delay line has been previously constructed to function effectively under these conditions, particularly in a vacuum environment.
The design features an aluminum carriage that is supported by four wheels, which are constrained to move along straight lines by a set of preloaded steel straps. This configuration minimizes friction to only rolling friction between different materials, thereby reducing the risk of vacuum adhesion that can occur when similar metals come into contact. The roller design offers several advantages over competing designs that utilize flex pivots, including greater robustness, stiffness, a larger range of motion, and compactness, all achieved with fewer components.
The work was conducted by a team from the Jet Propulsion Laboratory (JPL) at the California Institute of Technology, consisting of inventors James Moore, Mark Swain, and Peter Lawson. The project was sponsored by NASA, and the findings are documented in a technical support package dated November 1, 2002.
The document emphasizes the novelty of the delay line, highlighting its unique features and improvements over prior technologies. It addresses the motivation behind the development, which stems from the need for advanced interferometer components capable of functioning at cryogenic temperatures for space applications. The solution provided by the roller and strap-supported scanning delay line carriage is presented as a significant advancement in the field.
Overall, this document serves as a technical disclosure of a pioneering device that enhances the capabilities of interferometry in space, particularly for applications requiring precise measurements at low temperatures. The design's emphasis on minimizing vacuum adhesion and maximizing mechanical performance positions it as a valuable contribution to the field of cryogenic technology and space exploration.
