Page 310 - Inorganic Mass Spectrometry - Fundamentals and Applications

Multiple-Colle~tor ICP-MS 297

Differential Circular Vertical Einzel Horizontal Einzel
Extraction and -- Pumping Defining and Slit Steering Steering and
Aperture
Primary Steering f f Lenses Lenses R
I 11 0
Lenses f f Second
Sampler Focusing
I I
f f
Lens
1
I1 ~~ n
I1
I 1
Skimmer f
Mass Spectrometer
Defining Slit
Rotary Turbo 1 Turbo 2 Turbo 3
Figure 3 Details of the differential pumping, ion extraction, and focusing for the Nu In-
struments Nu Plasma.

sources, where the peak flat can only be measured by moving the collectors. The
Nu Plasma utilizes a variable dispersion zoom optic device overcome this prob-
to
lem, enabling the detectors to remain in fixed positions (Fig. 8.4) (Belshaw et al.,
1998). This greatly simplifies the complexity of the detector array, providing
since
greater reliability and more serviceability. Most importantly, no moving parts
are used in the design, fast changes of inst~mental configuration are possible, al-
lowing simple multielement isotopic analysis of small quantities of rnixed sam-
ples. The collectors are a new design of readily replaceable ceramic Faraday buck-

Ma net Collector
Array

Figure 4 Zoom lens effect with the Nu Inst~~e~ts Plasma.
Nu