Characteristics of a fast neutral atom source with electrons injected into the source through its emissive grid from the vacuum chamber

2012 ◽  
Vol 55 (2) ◽  
pp. 288-293 ◽  
Author(s):  
A. S. Metel ◽  
S. N. Grigoriev ◽  
Yu. A. Melnik ◽  
V. P. Bolbukov
Keyword(s):  
Vacuum Chamber ◽  
Neutral Atom ◽  
Emissive Grid ◽  
Atom Source

Extraction Discharge Source for Enhancing Analyte Line Intensities in Inductively Coupled Plasma Atomic Emission Spectrometry

1987 ◽  
Vol 41 (3) ◽  
pp. 391-395 ◽  
Author(s):  
R. S. Houk ◽  
B. R. Lafreniere ◽  
H. B. Lim ◽  
V. A. Fassel
Keyword(s):  
Inductively Coupled Plasma ◽  
Vacuum Chamber ◽  
Neutral Atom ◽  
Atomic Emission ◽  
Operating Conditions ◽  
Emission Spectrometry ◽  
Plasma Atomic Emission Spectrometry ◽  
Inductively Coupled ◽  
Line Intensities ◽  
High Ionization

A supplementary electrical discharge is generated by extraction of the axial channel of an Ar inductively coupled plasma (ICP) into a small vacuum chamber. The spectral background levels and background noise emitted by this discharge are similar to those from the ICP alone. The discharge enhances the intensities of ion lines by factors of up to 13 relative to intensities observed from the ICP alone. Neutral atom lines from elements with high ionization energies (≤9 eV) are also enhanced but by less than ion lines; neutral atom lines from easily ionized elements are suppressed by the discharge. Metal oxides in the ICP can be seen to dissociate into atomic species as they enter the discharge. These effects are attributed to more efficient atomization, excitation, and ionization in the discharge and to the tendency of analyte species to be constricted or concentrated closer to the central axis of the ICP as they flow into the discharge. Under the same operating conditions a 40-MHz plasma generates a more intense discharge and yields higher intensity enhancements than does a 27-MHz plasma.

Thin Pyrolytic Graphite Films for Electron Microscope Substrates

1971 ◽  
Vol 29 ◽  
pp. 226-227 ◽  
Author(s):  
George H. N. Riddle ◽  
Benjamin M. Siegel
Keyword(s):  
Vacuum Chamber ◽  
Pyrolytic Graphite ◽  
High Vacuum ◽  
Dark Field ◽  
Ultra High Vacuum ◽  
Graphite Substrate ◽  
Nickel Substrate ◽  
Routine Procedure ◽  
Field Electron Microscopy ◽  
Dark Field Electron

A routine procedure for growing very thin graphite substrate films has been developed. The films are grown pyrolytically in an ultra-high vacuum chamber by exposing (111) epitaxial nickel films to carbon monoxide gas. The nickel serves as a catalyst for the disproportionation of CO through the reaction 2C0 → C + CO2. The nickel catalyst is prepared by evaporation onto artificial mica at 400°C and annealing for 1/2 hour at 600°C in vacuum. Exposure of the annealed nickel to 1 torr CO for 3 hours at 500°C results in the growth of very thin continuous graphite films. The graphite is stripped from its nickel substrate in acid and mounted on holey formvar support films for use as specimen substrates.The graphite films, self-supporting over formvar holes up to five microns in diameter, have been studied by bright and dark field electron microscopy, by electron diffraction, and have been shadowed to reveal their topography and thickness. The films consist of individual crystallites typically a micron across with their basal planes parallel to the surface but oriented in different, apparently random directions about the normal to the basal plane.

New replica method with plasma polymerized film by glow discharge

1988 ◽  
Vol 46 ◽  
pp. 414-415
Author(s):  
A. Tanaka ◽  
M. Yamaguchi ◽  
T. Hirano
Keyword(s):  
Power Supply ◽  
Plasma Polymerization ◽  
Vacuum Chamber ◽  
Complex Surface ◽  
Replica Method ◽  
Metal Extraction ◽  
High Voltage Power Supply ◽  
Negative Glow ◽  
Hydrocarbon Gas ◽  
Hydrocarbon Molecules

The plasma polymerization replica method and its apparatus have been devised by Tanaka (1-3). We have published several reports on its application: surface replicas of biological and inorganic specimens, replicas of freeze-fractured tissues and metal-extraction replicas with immunocytochemical markers.The apparatus for plasma polymerization consists of a high voltage power supply, a vacuum chamber containing a hydrocarbon gas (naphthalene, methane, ethylene), and electrodes of an anode disk and a cathode of the specimen base. The surface replication by plasma polymerization in negative glow phase on the cathode was carried out by gassing at 0.05-0.1 Torr and glow discharging at 1.5-3 kV D.C. Ionized hydrocarbon molecules diffused into complex surface configurations and deposited as a three-dimensionally polymerized film of 1050 nm in thickness.The resulting film on the complex surface had uniform thickness and showed no granular texture. Since the film was chemically inert, resistant to heat and mecanically strong, it could be treated with almost any organic or inorganic solvents.

A vacuum chamber for low background diffraction experiments

1996 ◽  
Vol 211 (9) ◽  
Author(s):  
R. B. Neder ◽  
M. Burghammer ◽  
Th. Grasl ◽  
H. Schulz
Keyword(s):  
Single Crystal ◽  
Vacuum Chamber ◽  
Single Crystal Diffraction ◽  
Low Background

AbstractWe developed a small vacuum chamber for very low background single crystal diffraction experiments. The chamber has been designed for a large Eulerian cradle. The

Optimizing Gas-Assisted FIB Processes: The Importance of Oft-Ignored Secondary Parameters

2004 ◽  
Author(s):  
C. Rue ◽  
S. Herschbein ◽  
C. Scrudato ◽  
L. Fischer ◽  
A. Shore
Keyword(s):  
Focused Ion Beam ◽  
Vacuum Chamber ◽  
Ion Beam ◽  
Memory Capacity ◽  
Metal Films ◽  
Deposited Metal ◽  
Influence Process ◽  
Focused Beams ◽  
Gas Pressures

Abstract The efficiency of Gas-Assisted Etching (GAE) and depositions performed using the Focused Ion Beam (FIB) technique is subject to numerous factors. Besides the wellknown primary parameters recommended by the FIB manufacturer (pixel spacing, dwell time, and gas pressures), certain secondary factors can also have a pronounced effect on the quality of these gas-assisted FIB operations. The position of the gas delivery nozzle during XeF2 mills on silicon is examined and was found to affect both the milling speed and the texture on the floor of the FIB trench. Limitations arising from the memory capacity of the FIB computer can also influence process times and trench quality. Exposing the FIB vacuum chamber to TMCTS during SiO2 depositions is found to temporarily impede the performance of subsequent tungsten depositions, especially following heavy or prolonged TMCTS exposure. A delay period may be required to achieve optimal tungsten depositions following TMCTS use. Finally, the focusing conditions of the ion beam are found to have a significant impact on the resistance of FIB-deposited metal films. This effect is attributed to partial milling of the deposition film due to the intense current density of the collimated ion beam. The resistances of metal depositions performed with intentionally defocused ion beams were found to be lower than those performed with focused beams.

Evaluation of the airway mechanics of modified toggle laryngoplasty constructs using a vacuum chamber airflow model

2021 ◽  
Author(s):  
Sarah M. Gray ◽  
Santiago D. Gutierrez‐Nibeyro ◽  
Laurent L. Couëtil ◽  
Gavin P. Horn ◽  
Richard M. Kesler ◽  
...  
Keyword(s):  
Vacuum Chamber ◽  
Airway Mechanics ◽  
Airflow Model
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