Page 293 - Inorganic Mass Spectrometry - Fundamentals and Applications

~nalysis of Noncond~~tive Sample Types 2 79

Discharge Steel Ar Gas
Cell

Center
Conductor

Exit
Orifice

Tubing Tubing Sample
Holder 1
@$x@' Endcap
Sarnpk!

F

Radio frequency glow discharge mass spectrometry (rf GD-MS) source designs
employed on a VG GloQuad instrument for the analysis of a, Pin-type samples. (From Ref.
28.) b, Flat samples. (From Ref. 29.)

sources that allow for the analysis of flat, disk-type samples have been developed
for mounting on tbe end of DIP devices (Fig. '7.7b). As in the case of the pin-type
sources, detailed consideration of the interplay between discharge conditions and
ion extraction geometries is key to these developments. The analysis of disk sam-
ples is accomplisbed with either suitable mounts on the end o
that engages the sample against an ion volume anode to create
charge ~eomet~ (in much the same manner as in commercia
the