Mechanical vacuum systems System diagrams

In the schematic diagram of the vacuum line (Fig. 2.1) a U-bend is shown between the main tap T, and the manifold, which has two functions (a) It lends an extra element of mechanical flexibility to the system by absorbing small movements at the traps or along the main manifold (WL or WL ) which might otherwise lead to fracture and (b) it acts as a sink for non-volatile residues in the line and for grease which may be washed away from the taps 7, 7 and 7. ... 

Fig. 2. A schematic diagram of the skull melting apparatus. Not shown are protective screens around the vacuum cylinders, a transparent fused silica sleeve between the skull crucible and the r.f work coil, and a fume hood above the apparatus. (1) Skull crucible (2) work coil (3) to r.f. generator (4) 12-port vacuum collar (J) vacuum quick-connect coupling (6) Teflon insulating flange (7) water supply (in and out) for crucible (S) motor-driven gear system for lowering crucible (9) base plate and supporting frame, (10) 45.7-cm diameter X 30.5 cm high Pyrex vacuum cylinders (11) aluminum top plate (12) to mechanical pump.

A photograph and a schematic diagram of this system are shown in Figs. I and 2, respectively. It consists of a conventional stainless-steel UHV chamber within which an isolation cell for high-pressure studies is situated. The chamber is cylindrical in shape and has a diameter of 12 in. Ultrahigh vacuum is obtained by a mechanically backed Varian I 200 1/s diffusion pump with a liquid nitrogen trap, in combination with a water-cooled titanium sublimation pump. The background pressure of the system is lower than 1 X 10" Torr. 

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