The anti-contamination circuit of the Amsterdam isotope separator. I

Summary

A description is given of the circuit to prevent contamination of the collected isotopes in an electromagnetic isotope separator. In some cases the results of days or even weeks can be spoiled in a relatively short time when the material to be separated contains an isotope of low concentration. In order to get the highest purity obtainable with our separator and to avoid continuous observation of meters and instruments, the place and shape of the image in the focussing plane, near the collector, controls an automatic correcting circuit and safeguard system. The signals depending directly on the ion beam are part of:a. the beam shifting control, determining the position of the ion beam in the collector chambers by comparing the current to two electrodes near the collector.b. the beam intensity control, operating the safeguard system by comparing the total current to these electrodes with a reference current.c. the focussing control, also operating the safeguard system by a signal proportional to the fraction of the ion beam, striking a diaphragm before the collector.