scholarly journals Research on detection method of leakage rate of rough pumping valve in space environment simulator

2020 ◽  
Vol 198 ◽  
pp. 03015
Author(s):  
Wu Yue ◽  
Guo Qingliang ◽  
Fang Mingyuan ◽  
Sun Juan ◽  
Guo Ziyin ◽  
...  
Keyword(s):  
Detection Method ◽  
High Vacuum ◽  
Leakage Rate ◽  
Space Environment ◽  
Vacuum System ◽  
Pumping System ◽  
Vacuum Degree ◽  
Valve Leakage

As an important part of the vacuum system in the space environment simulator, the rough pumping system reduces the vacuum degree of the container from atmospheric pressure to the pressure of the high vacuum system when the space environment simulator starts up. As the key equipment of the rough pumping system, the rough pumping valve plays the role of isolating the rough pumping system from the environmental simulator, and its leakage rate has a direct impact on the vacuum degree that the space environment simulator can reach. Therefore, it is very important to detect the leakage rate of the rough pumping valve. In this paper, the leakage rate detection method of the rough pumping valve is introduced, including the valve delivery stage and valve installation stage to the simulator stage, in order to provide some basis for the follow-up valve leakage rate detection work

Vacuum System to Minimize the Specimen Contamination of High-Performance EM

1977 ◽  
Vol 35 ◽  
pp. 68-69
Author(s):  
N. Yoshimura ◽  
K. Shirota ◽  
T. Etoh
Keyword(s):  
Electron Microscope ◽  
High Speed ◽  
High Performance ◽  
High Vacuum ◽  
Vacuum System ◽  
Pump System ◽  
Pumping System ◽  
Diffusion Pump ◽  
Almost All ◽  
Cascade Type

One of the most important requirements for a high-performance EM, especially an analytical EM using a fine beam probe, is to prevent specimen contamination by providing a clean high vacuum in the vicinity of the specimen. However, in almost all commercial EMs, the pressure in the vicinity of the specimen under observation is usually more than ten times higher than the pressure measured at the punping line. The EM column inevitably requires the use of greased Viton O-rings for fine movement, and specimens and films need to be exchanged frequently and several attachments may also be exchanged. For these reasons, a high speed pumping system, as well as a clean vacuum system, is now required. A newly developed electron microscope, the JEM-100CX features clean high vacuum in the vicinity of the specimen, realized by the use of a CASCADE type diffusion pump system which has been essentially improved over its predeces- sorD employed on the JEM-100C.

An Experimental System Combining Medium Energy Electron Diffraction and Scanning Electron Microscopy

1973 ◽  
Vol 31 ◽  
pp. 136-137
Author(s):  
J.M. Cowley ◽  
F.A. Koch ◽  
J.L. Albain
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electron Diffraction ◽  
High Vacuum ◽  
Experimental System ◽  
Ultra High Vacuum ◽  
Vacuum System ◽  
Medium Energy ◽  
Pumping System ◽  
Scanning Electron

The theoretical and experimental advantages of using medium energy electrons (1-10 keV) instead of LEED and RHEED methods for quantitative surface studies were discussed by Moon and Cowley. A highly versatile ultra high vacuum system that exploits some of these advantages was constructed in our laboratory. The purpose of this paper is to describe design details of the instrument and to present initial data obtained.An overall view of the jinstrument is shown in Fig. 1. A commercially available field emission gun was attached to a Varian 240 LEED chamber. The pumping system is oil free and consists of cryosorbtion and Vaclon pumps.

Analysis and Achievement of the Leak Detection of High Vacuum System on Magnetron Sputtering Equipment

2011 ◽  
Vol 142 ◽  
pp. 71-74
Author(s):  
Jin Chun Feng ◽  
Song He Huang ◽  
Min Su
Keyword(s):  
Magnetron Sputtering ◽  
Integrated Circuit ◽  
High Vacuum ◽  
Leak Detection ◽  
Electronics Industry ◽  
Vacuum System ◽  
Vacuum Degree ◽  
The One ◽  
Substantial Decline ◽  
China’S Economy

Since the reform and opening, China's economy has achieved remarkable results, for various industries have developed rapidly. After 2 decades, 1950s and 1990s, China's vacuum industry also has get dramatic development and vacuum equipments have been widely applied in the electronics industry, especially in the semiconductor and integrated circuit production. This paper described the detection process and method of high vacuum magnetron sputtering equipment, utilized the one-by-one elimination to determine the key emphasis in work and succeeded in finding the cause of the substantial decline in the vacuum degree, then elaborated the results and effectiveness of detection, and finally made a conclusion. This paper has a referential significance on the maintenance of the same kind equipment.

scholarly journals Role of Material and its Processing for LIGO-India Ultra High Vacuum System

2013 ◽  
Vol 3 (1) ◽  
pp. 173-175
Author(s):  
Manoj Kumar Gupta ◽  
◽  
Rakesh Kumar ◽  
D.C. Raval ◽  
Kaushal Joshi ◽  
...  
Keyword(s):  
High Vacuum ◽  
Ultra High Vacuum ◽  
Vacuum System

A High Vacuum Emission Chamber for Scanning Electron Microscopy

1975 ◽  
Vol 33 ◽  
pp. 150-151
Author(s):  
W.R. Bottoms ◽  
G.B. Haydon ◽  
L. J. Anderson
Keyword(s):  
Source Region ◽  
High Vacuum ◽  
Cost Effective ◽  
Electron Source ◽  
Optical Systems ◽  
Vacuum System ◽  
Pumping System ◽  
Cost Effective Method ◽  
Time Required ◽  
Maintenance Requirements

The performance of modem commercial electron optical systems is normally limited by the quality of the electron source and this area of the instrument invariably consumes the greatest portion of the maintenance time required by the equipment. The development of a “clean” high vacuum system for the emission chamber, of electron beam apparatus can offer the possibility of improved resolution as well as lower maintenance requirements. Among the benefits of an improved vacuum in the electron source region are increased filament life, and compatibility with high brightness in the emission chamber. One cost effective method for providing an improved vacuum environment for the electron source region on existing equipment is to replace the emission chamber with another which is provided with its own clean pumping system.

Replication of Wet Objects and Cells

1974 ◽  
Vol 32 ◽  
pp. 102-103
Author(s):  
S. Basu ◽  
D. F. Parsons
Keyword(s):  
Water Vapor Pressure ◽  
High Vacuum ◽  
Polystyrene Latex ◽  
Vacuum System ◽  
Saturated Water Vapor ◽  
Replication Method ◽  
New Methods ◽  
Saturated Water ◽  
Water Vapors ◽  
Intermediate Chamber

We are approaching the invasiveness of cancer cells from the studies of their wet surface morphology which should distinguish them from their normal counterparts. In this report attempts have been made to provide physical basis and background work to a wet replication method with a differentially pumped hydration chamber (Fig. 1) (1,2), to apply this knowledge for obtaining replica of some specimens of known features (e.g. polystyrene latex) and finally to realize more specific problems and to improvize new methods and instrumentation for their rectification. In principle, the evaporant molecules penetrate through a pair of apertures (250, 350μ), through water vapors and is, then, deposited on the specimen. An intermediate chamber between the apertures is pumped independently of the high vacuum system. The size of the apertures is sufficiently small so that full saturated water vapor pressure is maintained near the specimen.

A Freeze Shadow Technique for the Preparation of Soft Paint Latexes for Electron Microscopy

1977 ◽  
Vol 35 ◽  
pp. 314-315
Author(s):  
Earl R. Walter ◽  
Glen H. Bryant
Keyword(s):  
Sample Preparation ◽  
High Vacuum ◽  
Vacuum System ◽  
Latex Particles ◽  
New Methods ◽  
Diffusion Pump ◽  
Film Forming ◽  
Routine Basis ◽  
Distribution Studies ◽  
Preparation Techniques

With the development of soft, film forming latexes for use in paints and other coatings applications, it became desirable to develop new methods of sample preparation for latex particle size distribution studies with the electron microscope. Conventional latex sample preparation techniques were inadequate due to the pronounced tendency of these new soft latex particles to distort, flatten and fuse on the substrate when they dried. In order to avoid these complications and obtain electron micrographs of undistorted latex particles of soft resins, a freeze-dry, cold shadowing technique was developed. The method has now been used in our laboratory on a routine basis for several years.The cold shadowing is done in a specially constructed vacuum system, having a conventional mechanical fore pump and oil diffusion pump supplying vacuum. The system incorporates bellows type high vacuum valves to permit a prepump cycle and opening of the shadowing chamber without shutting down the oil diffusion pump. A baffeled sorption trap isolates the shadowing chamber from the pumps.

Transmission Electron Microscopy of Evaporated Perylene Thin Films

1990 ◽  
Vol 48 (2) ◽  
pp. 336-337
Author(s):  
C. Ewins ◽  
J.R. Fryer
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Molecular Electronics ◽  
High Vacuum ◽  
Amorphous Layer ◽  
Electric Heater ◽  
Transmission Electron ◽  
Polycyclic Aromatic

The preparation of thin films of organic molecules is currently receiving much attention because of the need to produce good quality thin films for molecular electronics. We have produced thin films of the polycyclic aromatic, perylene C10H12 by evaporation under high vacuum onto a potassium chloride (KCl) substrate. The role of substrate temperature in determining the morphology and crystallography of the films was then investigated by transmission electron microscopy (TEM).The substrate studied was the (001) face of a freshly cleaved crystal of KCl. The temperature of the KCl was controlled by an electric heater or a cold finger. The KCl was heated to 200°C under a vacuum of 10-6 torr and allowed to cool to the desired temperature. The perylene was then evaporated over a period of one minute from a molybdenum boat at a distance of 10cm from the KCl. The perylene thin film was then backed with an amorphous layer of carbon and floated onto copper microscope grids.

Psychological Resilience Provides No Independent Protection From Suicidal Risk

Crisis ◽  
2016 ◽  
Vol 37 (2) ◽  
pp. 130-139 ◽  
Author(s):  
Danica W. Y. Liu ◽  
A. Kate Fairweather-Schmidt ◽  
Richard Burns ◽  
Rachel M. Roberts ◽  
Kaarin J. Anstey
Keyword(s):  
Risk Factors ◽  
Well Being ◽  
Current Status ◽  
Psychological Resilience ◽  
Cross Sectional ◽  
Life Project ◽  
Resilience Factors ◽  
First Time

Abstract. Background: Little is known about the role of resilience in the likelihood of suicidal ideation (SI) over time. Aims: We examined the association between resilience and SI in a young-adult cohort over 4 years. Our objectives were to determine whether resilience was associated with SI at follow-up or, conversely, whether SI was associated with lowered resilience at follow-up. Method: Participants were selected from the Personality and Total Health (PATH) Through Life Project from Canberra and Queanbeyan, Australia, aged 28–32 years at the first time point and 32–36 at the second. Multinomial, linear, and binary regression analyses explored the association between resilience and SI over two time points. Models were adjusted for suicidality risk factors. Results: While unadjusted analyses identified associations between resilience and SI, these effects were fully explained by the inclusion of other suicidality risk factors. Conclusion: Despite strong cross-sectional associations, resilience and SI appear to be unrelated in a longitudinal context, once risk/resilience factors are controlled for. As independent indicators of psychological well-being, suicidality and resilience are essential if current status is to be captured. However, the addition of other factors (e.g., support, mastery) makes this association tenuous. Consequently, resilience per se may not be protective of SI.

Abusive head trauma (AHT) outcome at long-term follow-up and the role of elective neurosurgical approach: A report of 22 cases

2013 ◽  
Author(s):  
Francesca Menegazzo ◽  
Melissa Rosa Rizzotto ◽  
Martina Bua ◽  
Luisa Pinello ◽  
Elisabetta Tono ◽  
...  
Keyword(s):  
Head Trauma ◽  
Abusive Head Trauma ◽  
Long Term Follow Up
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