The use of a shield for the reduction of fogging on photographic plates in spark-source mass spectrography

Abstract

In spark-source mass spectrography, secondary effects cause pronounced fogging of the photographic plate in the vicinity of the isotope lines of the major elements, and the limit of detection of elements whose lines fall within this area is considerably raised.

A shielding device has been designed to reduce the amount of ions produced by secondary effects and to prevent them from reaching the photographic plate. This reduces the background in the region of the major isotope lines and enables elements in this region to be determined with increased sensitivity and precision.