The Zeeman and Paschen-Back effects in strong magnetic fields

Abstract

The Zeeman effect in strong magnetic fields was first studied by Kapitza and Skinner (1925), the fields being obtained by a method developed by one of us (Kapitza 1924), in which an accumulator battery of small capacity was discharged through a coil. In this way it was possible to obtain magnetic fields up to 140,000 gauss during a time of 1/100 sec. It turned out that in such fields the majority of the spectral lines which were studied, split up (within the limits of experimental error) proportionally to the applied field, in accordance with the theory which had previously been verified only in weaker magnetic fields. An exception, however, was the zinc line at 4680 A, which gave a splitting about 10% greater than that predicted by the theory, this discrepancy being outside the limits of experimental error. Since then the method of producing strong magnetic fields has been considerably developed (Kapitza 1927); instead of the discharge of an accumulator the powerful current impulse from a short-circuited generator has been used, which has made possible the production of fields more than twice as great as those formerly obtained, and moreover, in considerably larger volumes. A the same time the technique of measuring the magnetic field has also been improved. Using these improvements we have made a new investigation of the Zeeman effect in fields up to 320,000 gauss, in which we have been able to increase considerably the accuracy of the measurements, and to explain the cause of the discrepancies previously found. We have also been able to investigate the Paschen-Back effect and to verify the theory of this effect.