The Zeeman Effect on the Helium Bands

Abstract

PROF. NICHOLSON has recently (Phil. Mag., vol. 50, p. 650, 1925) pointed out the importance of investigating the effect of a magnetic field on the so-called “doublet bands” of helium. He gives reasons for expecting that these particular bands should be subject to a Zeeman effect of the same general character as in the case of atomic line series. Apart from this, such. an investigation would be amply justified by the singularly interesting nature of these bands, both as regards their distribution in the spectrum according to a line-series law and the details of their structure (see Curtis and Long, Roy. Soc. Proc., A, vol. 108, p. 513, 1925). It happens that we had already completed the experimental part of such an investigation when Prof. Nicholson's paper appeared, and as the final results will not be ready for publication for some months, it may be of interest to describe their salient features at once.