Analysis of Solids with Mass Spectrometer

A Summary of Instrumentation

“…The first construction and use of a spark source instrument was reported by Gorman et al (1951) for the analyses of steel samples. A double-focusing mass analyzer is necessary to resolve the spark source ion beam, which has a large energy spread, according to Woolston and Honig (1964).…”

High-Sensitivity Mass Spectroscopy in Nuclear Studies

“…The high-frequency voltage, usually some 50 kv at 1 Mc, maintains a spark between the electrodes. To avoid welding the electrodes together, one feeds this high-frequency voltage to the electrodes in pulses of 10 -6 to 10-3 sec duration, at a repetition rate of 10 1 to 104 sect, the optimum pulse parameters being dependent on the electrode material (5,6) . The electrode material is evaporated and ionized in the spark, and the accelerated ions are then sepa rated into their different masses by the mass spectrograph.…”

“…Double-focusing instruments permit a considerable increase of the prod uct A· T as compared to the simple direction-focusing machines. It should be noted, however, that the realization of Equation 5 gives double focusing in first approximation only. The aperture angle a of the incident beam as well as the relative velocity deviation {3 =t:.v/vo from the nominal velocity must be small for the machines outlined in Table II so that the image defects which are proportional to a2, a{3, and {32 may be neglected.…”

Industrial Applications (Mass Spectrometry)

“…(28), who used a spark source in a Demp ster double-focusing analyzer. In order to overcome the fluctuations in the spark, they measured not the ion current at a given mass, but rather the ratio of that current to a fixed fraction of the total unresolved ion current.…”