Publications

Hochrein, James M.; Thornberg, Steven M.; Brown, Jason R.; White, Michael I.

Abstract not provided.

Thornberg, Steven M.; Irwin, Adriane N.; Boyd, Rachael D.; White, Michael I.; Hochrein, James M.; Brown, Jason R.

Abstract not provided.

Brown, Jason R.; Thornberg, Steven M.

Abstract not provided.

Thornberg, Steven M.; Brown, Jason R.; Bradley, Donald R.

Abstract not provided.

Thornberg, Steven M.; Irwin, Adriane N.; Hochrein, James M.; Brown, Jason R.; Wiemann, Dora K.

Abstract not provided.

Thornberg, Steven M.; Hochrein, James M.; Brown, Jason R.; Wiemann, Dora K.

Abstract not provided.

Hochrein, James M.; Brown, Jason R.; Jakaboski, Blake E.; Thornberg, Steven M.; Wavrik, Richard W.

Abstract not provided.

Thornberg, Steven M.; Irwin, Adriane N.; Hochrein, James M.; Brown, Jason R.; Wiemann, Dora K.

Abstract not provided.

Irwin, Adriane N.; Thornberg, Steven M.; Brown, Jason R.; Hochrein, James M.

HFE-7100 and FC-72 fluorinert are two fluids used during weapon component manufacturing. HFE-7100 is a solvent used in the cleaning of parts, and FC-72 is the blowing agent of a polymeric removable foam. The presence of either FC-72 or HFE-7100 gas in weapon components can provide valuable information as to the stability of the materials. Therefore, gas standards are needed so HFE-7100 and FC-72 gas concentrations can be accurately measured. There is no current established procedure for generating gas standards of either HFE-7100 or FC-72. This report outlines the development of a method to generate gas standards ranging in concentration from 0.1 ppm to 10% by volume. These standards were then run on a Jeol GC-Mate II mass spectrometer and analyzed to produce calibration curves. We present a manifold design that accurately generates gas standards of HFE-7100 and FC-72 and a procedure that allows the amount of each to be determined.

Polymer Degradation and Stability

Thornberg, Steven M.; Assink, Roger A.; Irwin, Adriane N.; Hochrein, James M.; Brown, Jason R.; Wiemann, Dora K.

Abstract not provided.

Thornberg, Steven M.; Brown, Jason R.

Abstract not provided.

Thornberg, Steven M.; Brown, Jason R.

Abstract not provided.

Thornberg, Steven M.; Assink, Roger A.; Alam, Mary K.; Hochrein, James M.; Brown, Jason R.; Irwin, Adriane N.; Wiemann, Dora K.

Abstract not provided.

Brown, Jason R.; Thornberg, Steven M.; Banet, Judith F.

Ensuring the reliability of all components within a weapon system becomes increasingly important as the stockpile ages. One of the most noteworthy surveillance techniques designed to circumvent (or take place alongside) traditional D&I operations is to collect a sample of gas from within the internal atmosphere of a particular region in a weapon. While a wealth of information about the weapon may be encoded within the composition of its gas sample, our access to that information is only as good as the method used to analyze the sample. It has been shown that cryofocusing-GC/MS offers advantages in terms of sensitivity, ease of sample collection, and robustness of the equipment/hardware used. Attention is therefore focused on qualifying a cryo-GC/MS system for routine stockpile surveillance operations at Pantex. A series of tests were performed on this instrument to characterize the linearity and repeatability of its response using two different standard gas mixes (ozone precursor and TO-14) at various concentrations. This paper outlines the methods used and the results of these tests in order to establish a baseline by which to compare future cryo-GC/MS analyses. A summary of the results is shown.

Thornberg, Steven M.; Hochrein, James M.; Brown, Jason R.; Wiemann, Dora K.; Clough, Roger L.

Abstract not provided.

Thornberg, Steven M.; Brown, Jason R.; Ordonez, Therese A.; Zavadil, Kevin R.; Ohlhausen, J.A.; Tallant, David T.; Garcia, Manuel J.; Simpson, Regina L.; Kent, Michael S.

Abstract not provided.

Hochrein, James M.; Ordonez, Therese A.; Brown, Jason R.

Abstract not provided.

Proposed for publication in Surface Science.

Thornberg, Steven M.; Alam, Mary K.; Brown, Jason R.

Abstract not provided.

Noek, Rachel M.; Thornberg, Steven M.; Brown, Jason R.

Abstract not provided.

Rivera, Dion A.; Rivera, Dion A.; Alam, Mary K.; Brown, Jason R.

Two lots of manufactured Type 3a zeolite samples were compared by TGA/IR analysis. The first lot, obtained from Davidson Chemical, a commercial vendor, was characterized during the previous study cycle for its water and water-plus-CO{sub 2} uptake in order to determine whether CO{sub 2} uptake prevented water adsorption by the zeolite. It was determined that CO{sub 2} did not hamper water adsorption using the Davidson zeolite. CO{sub 2} was found on the zeolite surface at dewpoints below -40 C, however it was found to be reversibly adsorbed. During the course of the previous studies, chemical analyses revealed that the Davidson 3a zeolite contained calcium in significant quantities, along with the traditional counterions potassium and sodium. Chemical analysis of a Type 3a zeolite sample retrieved from Kansas City (heretofore referred to as the ''Stores 3a'' sample) indicated that the Stores sample was a more traditional Type 3a zeolite, containing no calcium. TGA/IR studies this year focused on obtaining CO{sub 2} and water absorbance data from the Stores 3a zeolite. Within the Stores 3a sample, CO{sub 2} was found to be reversibly absorbed within the sample, but only at and below -60 C with 5% CO{sub 2} loading. The amount of CO{sub 2} observed eluting from the Stores zeolite at this condition was similar to what was observed from the Davidson zeolite sample but with a greater uncertainty in the measured value. The results of the Stores 3a studies are summarized within this report.