Mass spectrometer for ion-molecule interaction studies

Mass spectrometer for ion-molecule interaction studies

Vacuum news space simulation chambers. The pumps have a constant highpumping speed over a range from 5 x 10 -a to 5 × 10 -1° tort. The pumps range fro...

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Vacuum news space simulation chambers. The pumps have a constant highpumping speed over a range from 5 x 10 -a to 5 × 10 -1° tort. The pumps range from the PUL-02, which has a pumping speed of 100 litres/sec to the PUL-14 with a pumping speed of 500 litres/sec. By using a specially designed fractionating jet assembly the lowest ultimate pressure of 5 x 10-1° tort can be obtained without the use of a liquid-nitrogen trap if Ulvoil D-3 is used as pumping fluid. The small height and weight of the P U L pumps are claimed to be o n e of the outstanding features of these pumps and because of the compact heater design and quick-cooling device these pumps have a quick heat-up and cool-down. Degassed materials are used for the jet assembly so that a lower ultimate pressure is expected because of their lower outgassing rate. The pump body is made of stainless steel to minimize the outgassing. Refrigerant cooling of the upper parts of the pump body is also available.

Figure 2. VUH-40 valve System accessories. These include valves, feed-throughs, viewing port and flanges. The V U H series of valves are said to be bakeable to 450 °C, useful at 10 -x° tort and lower, have no variation in sealed conductance after hundreds of operations or tens of bakings at 450°C and have a high open conductance and a low sealed conductance. The valves are constructed entirely from low vapour pressure and vacuum-degassed materials, but with no organic materials in the vacuum. All parts are vacuum-degassed at 600 °C or higher. The feed-throughs available are bakeable up to 450 °C and can be used at 10-1° torr or lower. Their true leakage is less than 1 x 10 -1° torr litres/sec. Fine electron-beam welding has been used in the manufacture and no high vapour pressure organic material used. Both flanged and flangeless types are available. The glass viewing ports are also bakeable to 450°C and can be used down to 10 -1° torr and lower. They have wide vision, no organic material is used in their construction and both flanged and flangeless parts are available. Flanges available are bakeable up to 450 °C, are made of nonmagnetic stainless steel with gold wire used as the gasket. No trouble after repeated operation is said to be experienced with these flanges.

Manufactured by Ultek, the analyser, Series 200, has an entirely new principle of operation. The heart of the system consists of an ionizer, quadrupole section and ion detector. Because it uses no magnets, the Series 200 is extremely flexible and can be used on or in any vacuum system. The quadrupole tube, which is less than a foot long and weighs under 2 lb, can be m o u n t e d completely nude at any point within the vacuum chamber. It requires only electrical connections and is light enough to be supported by its own wiring if desired. The tube is bakeable to 400°C.

Europa VacuumEngineersLimited, UK Circle number 65 on Reader Enquiry Service card M a s s spectrometer for ion - molecule interaction studies A small, gold-plated mass spectrometer is being used as the ion source in another mass spectrometer designed for studying i o n molecule interactions. This "ion pre-selector" spectrometer, Nuclide's Model 1-90 G can be coupled with several types of m a s s analysers to form a " t a n d e m " analysing system. With the 1-90 G, the experimenter can introduce a mass-analysed ion beam into a reaction chamber to produce low-energy reactions between the ions and neutral molecules. The 1-90 G provides the low-energy primary ions for these reactions. The tandem analyser system is used for making precise measurements of the total cross-sections in ion - molecule interactions as functions of ion kinetic energy, as well as measurements of dissociation energies. The 1-90 G has a 90-degree magnetic deflection angle and a radius of curvature of the ion beam of 1 inch. It is said to achieve a resolution of M/A M of 40 and produces up to 10 -3 amps of 30-volt energy primary ions. Nuclide Corporation, Massachusetts, USA Circle number 66 on Reader Enquiry Service card Partial-pressure analyser A monopole partial-pressure analyser with a mass range of I to 600 has been developed by General Electric. Called Monopole " I I " , the upgraded model, now available, is claimed to have the broadest range on the high and ultra-high vacuum mass spectrometry market. When General Electric introduced a significantly smaller and lighter monopole device in October, 1964, its range was 1 to 300.Whereas unit resolution to mass 250 with 10 per cent valleys between adjacent peaks was attainable with last year's model, resolution to mass 600 can be reached with the new monopole device. These improvements are the result of a superior circuit design.

Japan VacuumEngineering Company, .lonan Circle number 64 on Reader Enquiry Service card

High-speed residual gas analyser A new quadrupole residual gas analyser marketed by Europa Vacuum Engineers Limited is said to scan an entire mass range in 10 millisecs and provide precision analyses in 50 millisecs. It gives high sensitivity to 10-15 torr (nitrogen) and is capable of resolution higher than the mass number in all mass ranges, with better than twice unit resolution at the lower two mass ranges. It has unit resolution at mass 500.

Dr T A Vanderslice operating the Monopole "11" partial-pressure analyser This new model is just as small and light as the previous monop o l e i i t can be carried in a satellite designed for studies of the vacuum in outer space. The device uses d.c. and radiofrequency voltages and does not require heavy and bulky magnets.

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