scholarly journals Simulation of Hall Thruster Plumes in a Vacuum Chamber Using a Hybrid Method

2008 ◽  
Author(s):  
Tyler Huismann ◽  
Iain Boyd
Keyword(s):  
Hybrid Method ◽  
Vacuum Chamber ◽  
Hall Thruster

scholarly journals Neutral density map of Hall thruster plume expansion in a vacuum chamber

2005 ◽  
Vol 76 (5) ◽  
pp. 053509 ◽  
Author(s):  
Mitchell L. R. Walker ◽  
Alec D. Gallimore
Keyword(s):  
Vacuum Chamber ◽  
Hall Thruster ◽  
Neutral Density ◽  
Plume Expansion ◽  
Density Map

scholarly journals Vacuum Chamber Pressure Maps of a Hall Thruster Cold-Flow Expansion

2004 ◽  
Vol 20 (6) ◽  
pp. 1127-1132 ◽  
Author(s):  
Mitchell L. R. Walker ◽  
Alec D. Gallimore ◽  
Iain D. Boyd ◽  
Chunpei Cai
Keyword(s):  
Vacuum Chamber ◽  
Hall Thruster ◽  
Chamber Pressure ◽  
Cold Flow

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

Sign in / Sign up

Export Citation Format

Share Document