Modeling of threshold conditions for scattering and absorption of radiation by mirror surfaces with condensed layers of residual gas particles

1994 ◽  
Author(s):  
L. S. Oleinikov
Keyword(s):  
Threshold Conditions ◽  
Residual Gas

Residual Gas Reactions in the Electron Microscope: I. Qualitative Observations on the Water Gas Reaction

1968 ◽  
Vol 26 ◽  
pp. 292-293
Author(s):  
Richard E. Hartman ◽  
Roberta S. Hartman ◽  
Peter L. Ramos
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Gas Phase ◽  
Absolute Temperature ◽  
Residual Gas ◽  
Gas Reactions ◽  
Image Position ◽  
The Right ◽  
Water Gas ◽  
Thinning Rate

The action of water and the electron beam on organic specimens in the electron microscope results in the removal of oxidizable material (primarily hydrogen and carbon) by reactions similar to the water gas reaction .which has the form:The energy required to force the reaction to the right is supplied by the interaction of the electron beam with the specimen.The mass of water striking the specimen is given by:where u = gH2O/cm2 sec, PH2O = partial pressure of water in Torr, & T = absolute temperature of the gas phase. If it is assumed that mass is removed from the specimen by a reaction approximated by (1) and that the specimen is uniformly thinned by the reaction, then the thinning rate in A/ min iswhere x = thickness of the specimen in A, t = time in minutes, & E = efficiency (the fraction of the water striking the specimen which reacts with it).

Recent Progress In High-Resolution Shadowing For Biological Transmission Electron Microscopy

1990 ◽  
Vol 48 (1) ◽  
pp. 510-511 ◽  
Author(s):  
Heinz Gross ◽  
Katarina Krusche ◽  
Peter Tittmann
Keyword(s):  
Heavy Metal ◽  
High Resolution ◽  
Freeze Drying ◽  
Atmospheric Conditions ◽  
Vacuum Equipment ◽  
Transmission Electron ◽  
Gas Atmosphere ◽  
Gas Molecules ◽  
Residual Gas ◽  
Backing Layer

Freeze-drying followed by heavy metal shadowing is a long established and straight forward approach to routinely study the structure of dehydrated macromolecules. Very thin specimens such as isolated membranes or single macromolecules are directly adsorbed on C-coated grids. After rapid freezing the grids are transferred into a suitable vacuum equipment for freeze-drying and heavy metal shadowing.To improve the resolution power of shadowing films we introduced shadowing at very low specimen temperature (−250°C). To routinely do that without the danger of contamination we developed in collaboration with Balzers an UHV (p≤10-9 mbar) machine (BAF500K, Fig.2). It should be mentioned here that at −250°C the specimen surface acts as effective cryopump for practically all impinging residual gas molecules from the residual gas atmosphere.Common high resolution shadowing films (Pt/C, Ta/W) have to be protected from alterations due to air contact by a relatively thick C-backing layer, when transferred via atmospheric conditions into the TEM. Such an additional C-coat contributes disturbingly to the contrast at high resolution.

Thermal soak compatibility test and residual gas analysis on 4130 steel and methanol thermosyphons

1997 ◽  
Author(s):  
Q. He ◽  
Pon Ponnappan ◽  
J. Brown ◽  
Q. He ◽  
Pon Ponnappan ◽  
...  
Keyword(s):  
Gas Analysis ◽  
Compatibility Test ◽  
Residual Gas

scholarly journals Silicon Oxide Etching Process of NF3 and F3NO Plasmas with a Residual Gas Analyzer

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3026
Author(s):  
Woo-Jae Kim ◽  
In-Young Bang ◽  
Ji-Hwan Kim ◽  
Yeon-Soo Park ◽  
Hee-Tae Kwon ◽  
...  
Keyword(s):  
Greenhouse Gas ◽  
Silicon Oxide ◽  
Gas Analysis ◽  
Gas Analyzer ◽  
Dc Offset ◽  
Cleaning Performance ◽  
Oxide Etching ◽  
Residual Gas ◽  
Etch Rates ◽  
Very High

The use of NF3 is significantly increasing every year. However, NF3 is a greenhouse gas with a very high global warming potential. Therefore, the development of a material to replace NF3 is required. F3NO is considered a potential replacement to NF3. In this study, the characteristics and cleaning performance of the F3NO plasma to replace the greenhouse gas NF3 were examined. Etching of SiO2 thin films was performed, the DC offset of the plasma of both gases (i.e., NF3 and F3NO) was analyzed, and a residual gas analysis was performed. Based on the analysis results, the characteristics of the F3NO plasma were studied, and the SiO2 etch rates of the NF3 and F3NO plasmas were compared. The results show that the etch rates of the two gases have a difference of 95% on average, and therefore, the cleaning performance of the F3NO plasma was demonstrated, and the potential benefit of replacing NF3 with F3NO was confirmed.

scholarly journals Residual Gas Adsorption and Desorption in the Field Emission of Titanium-Coated Carbon Nanotubes

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2937 ◽  
Author(s):  
Huzhong Zhang ◽  
Detian Li ◽  
Peter Wurz ◽  
Yongjun Cheng ◽  
Yongjun Wang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Field Emission ◽  
Photoelectron Spectroscopy ◽  
Gas Adsorption ◽  
Mass Spectrometry Analysis ◽  
Emission Characteristic ◽  
Spectrometry Analysis ◽  
Pristine Cnts ◽  
Xps Characterization ◽  
Residual Gas

Titanium (Ti)-coated multiwall carbon nanotubes (CNTs) emitters based on the magnetron sputtering process are demonstrated, and the influences of modification to CNTs on the residual gas adsorption, gas desorption, and their field emission characteristic are discussed. Experimental results show that Ti nanoparticles are easily adsorbed on the surface of CNTs due to the “defects” produced by Ar+ irradiation pretreatment. X-ray photoelectron spectroscopy (XPS) characterization showed that Ti nanoparticles contribute to the adsorption of ambient molecules by changing the chemical bonding between C, Ti, and O. Field emission of CNTs coated with Ti nanoparticles agree well with the Fowler–Nordheim theory. The deviation of emission current under constant voltage is 6.3% and 8.6% for Ti-CNTs and pristine CNTs, respectively. The mass spectrometry analysis illustrated that Ti-coated CNTs have a better adsorption capacity at room temperature, as well as a lower outgassing effect than pristine CNTs after degassing in the process of field emission.

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