A Differentially Pumped Ultra-high Vacuum System

2013 ◽  
pp. 55-59
Author(s):  
M. RIVERA ◽  
R. LE RICHE
Keyword(s):  
High Vacuum ◽  
Ultra High Vacuum ◽  
Vacuum System

scholarly journals Why Pressure Scales Cause So Much Confusion

1993 ◽  
Vol 1 (8) ◽  
pp. 5-6
Author(s):  
Anthony D. Buonaquisti
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Ambient Pressure ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Vacuum System ◽  
Scanning Auger Microprobe ◽  
The Mean ◽  
Scanning Electron

Pressure scales can be extremely confusing to new operators. This is not surprising. To my mind, there are three primary areas of confusion.Firstly, the pressure of gas inside an instrument changes over many orders of magnitude during pumpdown. The change is about 9 orders of magnitude for a traditional Scanning Electron Microscope and about 13 orders of magnitude for an ultra-high vacuum instrument such as a Scanning Auger Microprobe.To give an idea about the scale of change involved in vacuum, consider that the change in going from ambient pressure to that inside a typical ultra high vacuum system is like comparing one meter with the mean radius of the planet Pluto's orbit. The fact is that we don't often get to play with things on that scale. As a consequence, many of us have to keep reminding ourselves that 1 X 10-3 is one thousand times the value of 1 X 10-6 - not twice the value.

scholarly journals Optical contamination control in the Advanced LIGO ultra-high vacuum system

2013 ◽  
Author(s):  
Margot H. Phelps ◽  
Kaitlin E. Gushwa ◽  
Calum I. Torrie
Keyword(s):  
High Vacuum ◽  
Ultra High Vacuum ◽  
Vacuum System ◽  
Contamination Control

Development of an ultra-high vacuum system for space application

Vacuum ◽  
2004 ◽  
Vol 73 (2) ◽  
pp. 243-248 ◽  
Author(s):  
F. Grangeon ◽  
C. Monnin ◽  
M. Mangeard ◽  
D. Paulin
Keyword(s):  
High Vacuum ◽  
Ultra High Vacuum ◽  
Vacuum System ◽  
Space Application

scholarly journals Enhanced Ionic Conduction at the Film/Substrate Interface in LiI Thin Films Grown on Sapphire(0001)

1993 ◽  
Vol 318 ◽  
Author(s):  
D. Lubben ◽  
F. A. Modine
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Ionic Conduction ◽  
High Vacuum ◽  
Dislocation Motion ◽  
Ultra High Vacuum ◽  
Vacuum System ◽  
Substrate Interface ◽  
Interdigital Electrodes ◽  
Film Substrate

ABSTRACTThe ionic conductivity of LiI thin films grown on sapphire(0001) substrates has been studied in situ during deposition as a function of film thickness and deposition conditions. LiI films were produced at room temperature by sublimation in an ultra-high-vacuum system. The conductivity of the Lil parallel to the film/substrate interface was determined from frequency-dependent impedance measurements as a function of film thickness using Au interdigital electrodes deposited on the sapphire surface. The measurements show a conduction of ∼5 times the bulk value at the interface which gradually decreases as the film thickness is increased beyond 100 nm. This interfacial enhancement is not stable but anneals out with a characteristic log of time dependence. Fully annealed films have an activation energy for conduction (σT) of ∼0.47 ± .03 eV, consistent with bulk measurements. The observed annealing behavior can be fit with a model based on dislocation motion which implies that the increase in conduction near the interface is not due to the formation of a space-charge layer as previously reported but to defects generated during the growth process. This explanation is consistent with the behavior exhibited by CaF2 films grown under similar conditions.

An ultra high vacuum system for thin dielectric film deposition at low temperatures

1988 ◽  
Vol 3 (5) ◽  
pp. 951-957
Author(s):  
R. P. H. Chang ◽  
G. Griffiths
Keyword(s):  
Low Temperatures ◽  
High Vacuum ◽  
Oxide Films ◽  
Film Deposition ◽  
Ultra High Vacuum ◽  
Oxide Semiconductor ◽  
Vacuum System ◽  
Phosphorus Oxide ◽  
Electrical Measurements ◽  
Crystal Surfaces

An ultra high vacuum system has been designed and constructed for the purpose of depositing high-quality oxide films on well-characterized crystal surfaces at low temperatures. In particular, aluminum phosphorus oxide films have been deposited on both In P and Ge surfaces for the purpose of device application. Electrical measurements of metal-oxide-semiconductor structures show much improved interfacial properties with little or no hysteresis.

Eine Methode zur Messung geringster Ölbedeckungen in Vakuumsystemen

1967 ◽  
Vol 22 (4) ◽  
pp. 549-553 ◽  
Author(s):  
R. Dobrozemsky ◽  
W. K. Huber ◽  
F. Viehböck
Keyword(s):  
High Vacuum ◽  
High Sensitivity ◽  
Radioactive Tracer ◽  
Operating Conditions ◽  
Ultra High Vacuum ◽  
Vacuum System ◽  
First Results ◽  
Tracer Isotope ◽  
Radioactive Tracer Method ◽  
Vacuum Systems

To get information on extremely small organic deposits in ultra high vacuum systems the sensitivity of most of the conventional methods for thickness measurements is not high enough. On the other hand the radioactive tracer method has shown its high sensitivity and wide versatility in many fields. Tritium with a half life of 12.3 γ and a mean β-energy of 5.4 keV was choosen as tracer isotope. A method is described for Tritium-labelling diffusion pump oils with specific activities up to 100 mC/g. Using the liquid scintillation counting technique one can detect deposits down to below 1010 molecules/cm2. First results with this Tritium labelled pump fluid are given under different operating conditions in an all metal ultra high vacuum system.

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