Mattauch-Herzog double-focusing

Fig. 4.22. Mattauch-Herzog double-focusing mass spectrograph providing direction and momentum focusing of ions on a plane. [73] Reprinted from Ref. [1] with permission. American Association for the Advancement of Science, 1979.

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). 

In focal-plane detectors, the simultaneous detection of all spatially dispersed multiplex detection) ions is achieved, resulting in several orders of improvement in detection efficiency over that of focal-point detectors [87]. A photographic plate is the earliest example of focal-plane detection which in the past was used in conjunction with Mattauch-Herzog double-focusing mass spectrometers. 

FIGURE 8.4 The principles of the Mattauch-Herzog double-focusing magnetic sector mass spectrometer with a simultaneous detector plane. (Courtesy of SPECTRO Analytical Instruments GmhH, Kleve, Germany.)... 

Mattauch-Herzog geometry. An arrangement for a double-focusing mass spectrometer in which a deflection of n/A radians in a radial electrostatic field is followed by a magnetic deflection of nil radians. 

J. Mattauch and R. F. K. Herzog. Z. Physik. 89,786, 1934. This is the original paper showing the double-focusing geometry necessary to focus onto a plane rather than at a single point. 

Spark ion source in spark plasma by e impact plasma 50 000 ne 1 018-1019 crrr3 M+ high < 1( 4 Pa double-focusing SFMS (Mattauch-Herzog) traces, high-purity materials, geology... 

Mattauch-Herzog type mass spectrometer has double-focusing properties for ions of all masses... 

Double-focusing mass spectrometers with Mattauch-Herzog geometry and high mass resolution have been used for a long time, especially in nuclear physics, for the precise determination of exact... 

Figure 3.6 Schematicofa double-focusing sector field mass spectrograph with Mattauch-Herzog geometry with a linear imaging curve (double focusing for ions of all masses simultaneously) modified field combination with 70°. In the mass spectrograph, photographic ion detection or focal plane array detectors are used for quasi-simultaneous detection of separated ion beams. (H. Kienitz (ed.), Massen-spektrometrie (1968), Verlag Chemie, Weinheim. Reproduced by permission of Wiley-VCH)...

Recently, Hieftje et al.15-16 equipped a small double-focusing mass spectrograph built in house with Mattauch-Herzog geometry with several ion sources (such as glow discharge, an inductively coupled plasma ion source or a microwave plasma torch) and a novel array detector for simultaneous ion detection. 

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.)...

Figure 16.5—Magnetic analyser mass spectrometer, a) Nier Johnson system, b) directional focusing properties of the magnetic field, c) principle of a double focusing mass spectrometer d) Mattauch-Herzog system.

In 1967 Liebl reported the development of the first imaging SIMS instrument based on the principle of focused ion beam scanning [24]. This instrument, the ion microprobe mass analyzer, was produced by Applied Research Laboratories (Fig. 4.5). It used an improved hollow cathode duoplasmatron [25] ion source that eliminated filaments used in earlier sources and allowed stable operation with reactive gases. The primary ion beam was mass analyzed for beam purity and focused in a two-lens column to a spot as small as 2 pm. The secondary ions were accelerated from the sample surface into a double focusing mass spectrometer of Mattauch-Herzog geometry. Both positive and negative secondary ions were de-... 

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