544. Method of degassing the walls and internal fittings of high-vacuum chambers

Vacuum ◽  
1971 ◽  
Vol 21 (7) ◽  
pp. 287
Keyword(s):  
High Vacuum ◽  
Vacuum Chambers

Brazing Vacuum Ceramic Tubes - A Diffusion Profile in the Joint

2016 ◽  
Vol 367 ◽  
pp. 86-95
Author(s):  
Osmar Roberto Bagnato ◽  
R.F. Francisco ◽  
A.L. Gobbi ◽  
Tatiane Falvo ◽  
P.M. Pimentel
Keyword(s):  
Electron Beam ◽  
High Vacuum ◽  
Diffusion Profile ◽  
Film Deposition ◽  
High Brightness ◽  
Vacuum Chambers ◽  
Ceramic Components ◽  
Synchrotron Light ◽  
The Magnetic Field ◽  
Design Construction

The Sirius Project is an initiative of the Brazilian Synchrotron Light Laboratory - LNLS (CNPEM - MCTI), for the design, construction and operation of a new synchrotron radiation source 3rd generation, with high brightness and energy of the electrons of 3.0 GeV. Among many other components there will be built 80 ceramic cameras embedded in special magnets, whose function is to act to correct the orbit of the electron beam in the storage ring. The ceramic chamber is crucial for this application because this material is transparent to the magnetic field generated in the electro magnet and thus acts directly on the electron beam. The difficulty of these constructive components lies in the fact that, the ceramic components must be attached to metal components will join vacuum chambers that make up the ring, and then must present excellent mechanical and vacuum tight. The process of chemical bonding between the ceramic and metal components is performed by brazing in high vacuum. After brazing, a film is deposited of copper with 7 micrometers thickness. The objective of this paper is to describe the process of film deposition and brazing of copper and the excellent results obtained in the production, mechanical characterization, microstructural and tightness.

scholarly journals Densities, infrared band strengths, and optical constants of solid methanol

2018 ◽  
Vol 617 ◽  
pp. A116 ◽  
Author(s):  
Ramón Luna ◽  
Germán Molpeceres ◽  
Juan Ortigoso ◽  
Miguel Angel Satorre ◽  
Manuel Domingo ◽  
...  
Keyword(s):  
Infrared Spectra ◽  
Optical Constants ◽  
High Vacuum ◽  
Laboratory Data ◽  
Laser Interferometry ◽  
Infrared Band ◽  
Vacuum Chambers ◽  
Iterative Minimization ◽  
Minimization Procedure ◽  
Different Thickness

Contact. The increasing capabilities of space missions like the James Webb Space Telescope or ground-based observatories like the European Extremely Large Telescope demand high quality laboratory data of species in astrophysical conditions for the interpretation of their findings. Aims. We provide new physical and spectroscopic data of solid methanol that will help to identify this species in astronomical environments. Methods. Ices were grown by vapour deposition in high vacuum chambers. Densities were measured via a cryogenic quartz crystal microbalance and laser interferometry. Absorbance infrared spectra of methanol ices of different thickness were recorded to obtain optical constants using an iterative minimization procedure. Infrared band strengths were determined from infrared spectra and ice densities. Results. Solid methanol densities measured at eight temperatures vary between 0.64 g cm−3 at 20 K and 0.84 g cm−3 at 130 K. The visible refractive index at 633 nm grows from 1.26 to 1.35 in that temperature range. New infrared optical constants and band strengths are given from 650 to 5000 cm−1 (15.4–2.0 μm) at the same eight temperatures. The study was made on ices directly grown at the indicated temperatures, and amorphous and crystalline phases have been recognized. Our optical constants differ from those previously reported in the literature for an ice grown at 10 K and subsequently warmed. The disagreement is due to different ice morphologies. The new infrared band strengths agree with previous literature data when the correct densities are considered.

The Seal System in Aerostatic Journal Bearings for High Vacuum Chambers

2004 ◽  
Vol 126 (2) ◽  
pp. 310-315 ◽  
Author(s):  
S. Yoshimoto ◽  
Y. Yoshida ◽  
K. Yagi
Keyword(s):  
Pressure Distribution ◽  
Vacuum Chamber ◽  
Journal Bearing ◽  
High Vacuum ◽  
Journal Bearings ◽  
Vacuum Pump ◽  
Chamber Pressure ◽  
Design Parameters ◽  
Vacuum Chambers ◽  
High Vacuum Chamber

This paper investigates the performance of a seal system for an aerostatic journal bearing used in a high vacuum chamber. The seal system consists of axially spaced viscous seals and annular exhaust grooves that are located between the viscous seals. Each exhaust groove is coupled to a separate vacuum pump in order to achieve a vacuum chamber pressure of less than 10−3 Pa. The vacuum chamber pressure is affected by design parameters such as the number of viscous seal stages, seal length, seal gap, and exhaust tube conductance. The influence of these design parameters on the pressure distribution across seal regions and the vacuum chamber pressure are discussed theoretically. It is subsequently shown that an aerostatic journal bearing with three-stage seal system installed can obtain a reduction in the vacuum chamber pressure almost to the ultimate pressure of a vacuum pump, providing there is no leak or outgassing from materials.

Design, Manufacturing and Pump-down Curve Simulation of High Vacuum Systems

2012 ◽  
Vol 220-223 ◽  
pp. 575-579
Author(s):  
Tien Tung Chung ◽  
Chih Kang Lu ◽  
Yi Ting Tu
Keyword(s):  
Vacuum Chamber ◽  
Extreme Ultraviolet ◽  
High Vacuum ◽  
Vacuum Pressure ◽  
Vacuum System ◽  
Extreme Ultraviolet Lithography ◽  
Ultraviolet Lithography ◽  
Vacuum Chambers ◽  
Equivalent Length ◽  
Vacuum Systems

This paper presents a vacuum system design for extreme ultraviolet lithography (EUV) and studies the prediction of pump-down curves for vacuum chambers. Related basic theories include gas laws, conductance for several kinds of flow regimes, equivalent length for pipes, outgassing, diffusion, and permeation etc. The simulation program consists of a MFC module and a MATLAB module. The MFC module is used to input necessary parameters, including start and target pressure for pumping, volume and inner surface area of vacuum chambers, configuration of pumping lines, performance of vacuum pumps, and gas loads. The MATLAB module deals with the pump-down curve calculation based on related theories. The governing equation of the conservation of mass in a pumped vacuum chamber is derived from extended Temkin isotherm. The pump-down curve of vacuum chamber is predicted by four steps, including calculation of equivalent length for pipes, conductance of pipes, and effective pumping speed of pumps, and pump-down time. An empty vacuum chamber is used to test the developed program. The pump-down curve reaches 6.5E-8 torr with 42 hours pump-down time in experiment measurement, and the simulated curve reaches 5.79E-8 torr at the same time point. The developed program can predict pump-down curve with a good accuracy in the range from low vacuum pressure to high vacuum pressure.

scholarly journals The high-field magnet endstation for X-ray magnetic dichroism experiments at ESRF soft X-ray beamline ID32

2016 ◽  
Vol 23 (2) ◽  
pp. 464-473 ◽  
Author(s):  
K. Kummer ◽  
A. Fondacaro ◽  
E. Jimenez ◽  
E. Velez-Fort ◽  
A. Amorese ◽  
...  
Keyword(s):  
High Field ◽  
High Vacuum ◽  
Surface Preparation ◽  
Ultra High Vacuum ◽  
Experimental Conditions ◽  
X Ray ◽  
Vacuum Chambers ◽  
Superconducting Coils ◽  
Magnetic Dichroism ◽  
High Field Magnet

A new high-field magnet endstation for X-ray magnetic dichroism experiments has been installed and commissioned at the ESRF soft X-ray beamline ID32. The magnet consists of two split-pairs of superconducting coils which can generate up to 9 T along the beam and up to 4 T orthogonal to the beam. It is connected to a cluster of ultra-high-vacuum chambers that offer a comprehensive set of surface preparation and characterization techniques. The endstation and the beam properties have been designed to provide optimum experimental conditions for X-ray magnetic linear and circular dichroism experiments in the soft X-ray range between 400 and 1600 eV photon energy. User operation started in November 2014.

Synthesis of Ti-Zr-V Non-Evaporable Getter Thin Films Grown on Al Alloy and CuCrZr Alloy

2017 ◽  
Vol 730 ◽  
pp. 87-94 ◽  
Author(s):  
Ling Hui Wu ◽  
Chia Mu Cheng ◽  
Chin Shueh ◽  
Che Kai Chan ◽  
Chin Chun Chang ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Defects ◽  
Substrate Surface ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Al Alloy ◽  
Metallic State ◽  
Vacuum Chambers ◽  
Nanocrystalline Structures ◽  
Surface Morphologies

The Ti-Zr-V non-evaporable getter (NEG) films were grown on Aluminum (Al) alloy and CuCrZr alloy, which can be used to fabricate the vacuum chambers in the ultra-high vacuum status. The Al alloy and CuCrZr alloy samples with different surface roughness were prepared by the different manufacturing methods. We studied whether the behavior and the microstructure of the Ti-Zr-V getter films are influence by the surface roughness of the substrate. The surface morphologies of Ti-Zr-V NEG films appear distinct and the growth of the films follows the nature of the substrate surface. The Ti-Zr-V films have nanocrystalline structures and the grain sizes of the films become slightly larger with increasing the surface smoothness. In addition, it was found that the reduction of the Ti-Zr-V NEG films to the metallic state was affected by presence of surface defects on the films. The surface defects should result from the existence of micro-pores, pockmarks, and micro-cracks on the original substrate, which produced from the manufacturing process.

Optical and Morphological Characterization of PTCDI-C13

2008 ◽  
Vol 1091 ◽  
Author(s):  
Marco Stella ◽  
Fernando Villar ◽  
Fredy Enrique Rojas ◽  
Mónica Della Pirriera ◽  
Cristobal Voz ◽  
...  
Keyword(s):  
Thin Films ◽  
Substrate Temperature ◽  
High Vacuum ◽  
Organic Thin Films ◽  
Morphological Characterization ◽  
Force Microscopy ◽  
Vacuum Chambers ◽  
Photothermal Deflection Spectroscopy ◽  
Atomic Force ◽  
Deposition Parameters

AbstractThe organic photovoltaic technology has developed much in the last few years thanks to the optimization of the solar cell geometry and, specially, to the research for new performing materials. Nevertheless, much work has still to be done in order to better know the real mechanisms regulating the function of such novel class of semiconductors. The study of thin-film micro-structure, and the influence of the deposition parameters on it, is an important issue in order to obtain best optical and electrical properties. Thermal evaporation in high-vacuum chambers is the more suitable deposition technique to obtain organic thin-films with well organize molecular structure. Deposition parameters such as the substrate temperature and deposition rate may have some important effect on the molecules ordering. In this paper the effects of substrate temperature on structural and optical properties have been studied for N,N′-ditridecyl perylene diimide (PTCDI-C13) thin-films. Four samples have been deposited at 30, 60, 90 and 120°C substrate temperature and their absorption has been investigated by photothermal deflection spectroscopy (PDS) and transmittance spectroscopy. Moreover, simulations of the transmittance spectra have been calculated in order to obtain the optical constants n and k. Finally atomic force microscopy (AFM) has been employed to analyze the superficial morphology of the thin-films.

Sign in / Sign up

Export Citation Format

Share Document