Ultra-high vacuum system

The ultra-high vacuum chamber is commonly made from stainless steel, and joints of chamber parts are made from crushed copper gaskets. Ultra-high vacuum pressure can be achieved using diffusion pumps, sputter ion pumps or turbomolecular pumps. Currently, sputter ion pumps and turbomolecular pumps are more commonly used than diffusion pumps that may contaminate the chamber by leaking oil gas molecules. 

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Low pressure studies Adsorption of CO. The experiments were performed in an ultra-high vacuum system described previously (1). The data obtained on palladium particles with a size smaller than 2 nm or larger than 3 nm will be discussed in turn. 

To get around the difficulties involved in preparing for study an interface consisting of a monolayer of polyimide on a metal substrate, vapor-deposited components of polyimide (9-111 and model molecules for parts of the polyimide (11-121 on metals have been studied recently. Due to the limited size of these model molecules, they can be vapor-deposited in monolayers on the surface of clean metallic substrate in an ultra high vacuum system. In this way, useful information concerning the initial interface formation of (parts of) polyimide on a metal surface can be obtained. 

The experimental set-up was described earlier (ref. 6). The self-supported samples were activated for 30 min at 670 K in an ultra-high vacuum system. 

Our apparatus is considered to need pulsed valves, an ultra high vacuum system and Time of flight mass spectroscopy (TOP) because of the above requirements (Fig. 2). We call our newly developed apparatus Toyota Timc-rcsoIvcd Timc-of-llighi Mass-spcctromcicr with Molecular-Pulsc-Probc Reaction Analysis at the Surface of a Catalyst (TMPRAS TM+)... 

The group of Nishimura has evaporated 100 nm thick films of palladium onto both sides of foils of vanadium alloyed with nickel, aluminum and molybdenum in an ultra-high vacuum system equipped for physical vapor deposition [62-66]. 

In this study the Multitrack system, a TAP-like system [9], was used. In Figure 1 a schematical representation is given. A small reactor (7 mm inner diameter, bed height 10 mm) is located in an ultra-high vacuum system. Small amounts of reactants (lO -lO o molecules, 100 ps pulse width) can be pulsed into the reactor that typically operates at a pressure of 3 Pa. At the reactor exit the reaction products are analyzed by a quadrupole mass spectrometer. As this mass... 

The high sensitivity, high resolving power, accurate mass measurement, and MS" capability make it attractive for structure elucidation. However, the combined requirements of an ultra-high vacuum system, superconducting magnets to... 

The Interpretation of Data Obtained in Ultra-High Vacuum Systems... 

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