Detectors
Conversion dynode
Exhibit no. 612
This exhibit is a conversion dynode, a kind of deflector electrode sometimes put in front of the detector (electron multiplier).
It consists of a highly polished cylindrical bar mounted on a stainless steel rod. The electrode surface is held at high voltage with reverse polarity to the measured ions. The ions striking the surface produce secondary charged particles that are subsequently detected. A conversion dynode makes it possible to detect negative ions and increase the signal intensity of high mass ions. This particular exhibit comes from a sector mass spectrometer ZAB-EQ manufactured by VG Analytical LTD. in 1986.