Vacuum Ultraviolet (VUV)Facility

NASA Glenn Research Center
Space Environment and Experiments Branch

Vacuum Ultraviolet (VUV) Facility

The vacuum ultraviolet (VUV) facility enables steady-state accelerated solar radiation exposure of materials and coatings in a highly clean vacuum facility. Results from testing in this facility can be used to predict in-space performance of coatings and surfaces for ultraviolet.

The vacuum ultraviolet facility is contained within a cryogenically pumped high vacuum chamber which achieves a system pressure of approximately 5 x 10-6-torr. The chamber contains four individual vacuum ultraviolet exposure compartments in vacuum separated by water-cooled copper walls to minimize sample contamination and thermal cross-interactions between compartments.

Each exposure compartment contains a vacuum ultraviolet deuterium lamp with a magnesium fluoride window, a motor-controlled sample stage coupled with a vacuum ultraviolet detector, and two thermocouples for temperature measurement. Exposure area in each compartment is approximately 7.5 cm diameter. The vacuum ultraviolet lamps provide wavelengths above 115 nm, and the wavelength range between 115 nm and 200 nm can be provided at one to five times the in-space solar intensity in this same wavelength range.

One of the compartments can, alternatively or additionally, use a near ultraviolet (NUV) lamp to provide wavelengths between 220 nm and 400 nm at approximately five times the Sun’s intensity.

Three of the four exposure compartments are also equipped with controlled heaters located within the sample holder for conducting exposures at elevated temperatures.

Compartments are individually adjusted for exposure conditions, so that multiple tests can be conducted at the same time.

Exposure conditions can be recorded by a PC-based data acquisition system, so that the system can run unattended.

VACUUM ULTRAVIOLET (VUV) FACILITY

INTERNAL PICTURE OF VACUUM ULTRAVIOLET FACILITY

VUVInterior

Durability of solar array bi-stem thermal-shield materials for Hubble Space Telescope first servicing mission.
Screening of candidate thermal blanket materials for James Webb Space Telescope.
Studying wavelength dependence and intensity dependence of vacuum ultraviolet degradation of polymer films.
Screening candidate elastomers for advanced docking and berthing systems.

Studying effects of vacuum ultraviolet and near ultraviolet radiation on surfaces and coatings.
Providing calibration of vacuum ultraviolet detectors and sources.