Double-focusing spark source mass spectrometer

Figure 1. Schematic diagram of a double focusing spark source mass spectrometer...

Figure 5.24 Experimental setup of a double-focusing sector field mass spectrometer with Mattauch-Herzog geometry with interchangeable spark and laser ion source. (/. 5. Becker and H. /. Dietze, Int. /. Mass Spectrom. Ion Proc. 197, 1 (2000). Reproduced by permission of Elsevier.)...

Of course, the electron-impact source cannot be used if nonvolatile inorganic samples such as metal alloys or ionic residues are to be analyzed. These substances can be investigated using a different kind of ionization chamber called a spark source, similar to the excitation sources used in emission spectroscopy (Chap. 11). The other parts of the spectrometer can be the same as a general-purpose instrument however, a Mattauch-Herzog double-focusing instrument is preferred (Fig. 16.7 below), because the spark source produces ions with a wide spread of kinetic energies. The entire device is known as a spark-source mass spectrometer (SSMS). 

The glow-discharge source appears to be more stable than the spark source and is less expensive to purchase and operate. It is particularly useful for the direct analysis of solid samples. Commercial quadrupole and double-focusing mass spectrometers with glow-discharge sources are now on the market. 

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