U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Publications by: Robert F. Berg (Assoc)

Search Title, Abstract, Conference, Citation, Keyword or Author
Displaying 1 - 25 of 119

Oxidation caused by water outgassed from the thermal blanket on the SDO spacecraft

June 23, 2023
Author(s)
Robert F. Berg, Charles S. Tarrio, FRANCIS EPARVIER, ANDREW JONES
The Solar Dynamics Observatory (SDO) is a sun-observing spacecraft that includes two spectrometers that use aluminum membranes to filter solar radiation. The transmission of those filters degraded by a factor of 5 during the first five years after launch

Measurements and model of UV-induced oxidation of aluminum

March 22, 2023
Author(s)
Robert F. Berg, Charles S. Tarrio, Thomas B. Lucatorto
We present measurements and a model of aluminum oxidation induced by ultraviolet (UV) radiation. Spots of oxide were grown by focusing synchrotron radiation onto a polycrystalline aluminum membrane in the presence of water vapor at pressures from 3×10-8

The hazard of UV-induced oxidation to solar-viewing spacecraft optics

March 2, 2023
Author(s)
Charles S. Tarrio, Robert F. Berg, Thomas B. Lucatorto, Dale E. Newbury, Nicholas Ritchie, Andrew Jones, Frank Eparvier
The two most prevalent outgas contaminants on satellites are organic molecules and water vapor. Adsorbed organic molecules can degrade a solar-viewing instrument when they are cracked by ultraviolet radiation (UV) and become a light-absorbing layer of

Silicone tube humidity generator

February 16, 2022
Author(s)
Robert F. Berg, Nicola Chiodo, Eric Georgin
We describe the model and construction of a two-flow (or divided-flow) humidity generator, developed at LNE-CNAM, that uses mass flow controllers to mix a stream of dry gas with a stream of humid gas saturated at 28 °C. It can generate a wide range of

Evidence Against Carbonization of the Thin-Film Filters of the Extreme Ultraviolet Variability Experiment onboard the Solar Dynamics Observatory

April 1, 2021
Author(s)
Charles Tarrio, Robert F. Berg, Thomas B. Lucatorto, Andrew Jones, Frank Eparvier, Brian Templeman, Donald Woodraska, Marie Dominique
In spite of strict limits on outgassing from organic materials, some spacecraft instruments making long-term measurements of solar extreme ultraviolet (EUV) radiation still suff er signi cant degradation. While such measures have reduced the rate of

Optics Contamination

February 5, 2018
Author(s)
Charles S. Tarrio, Shannon B. Hill, Robert F. Berg, Sasa Bajt

Time dependence in static measurements of vapor pressure

November 17, 2015
Author(s)
Robert F. Berg
The static method for measuring vapor pressure assumes that the sample is pure and that its temperature is steady and uniform. In practice, the measured pressure may be time dependent due to evaporative cooling after pumping on the sample, transpiration of

Thermally stable thin-film filters for high-power extreme-ultraviolet applications

November 12, 2015
Author(s)
Charles S. Tarrio, Robert F. Berg, Thomas B. Lucatorto, Bruce Lairson, Heidi Lopez, Travis Ayers
We investigated several types of thin-film filters for high intensity work in the extreme-ultraviolet (EUV) spectral range. In our application, with a peak EUV intensity of 2.7 W cm-2, Ni-mesh-backed Zr filters have a typical lifetime of 20 hours, at which

Viscosity-ratio measurements with capillary viscometers

May 20, 2014
Author(s)
Robert F. Berg, Eric F. May, Michael R. Moldover
Viscosity-ratio measurements made with capillary viscometers exploit the accurate values of the viscosity of helium resulting from ab initio calculations. Accurate values of the argon-to-helium viscosity ratio are now used for primary acoustic thermometry

Hydrogen traps in the outgassing model of a stainless steel vacuum chamber

March 31, 2014
Author(s)
Robert F. Berg
This article describes a model for hydrogen outgassing into a stainless steel vacuum chamber. It accounts for the geometry of the chamber components, the hydrogen dissolved in those components, and the processes of diffusion, recombination, and trapping