Progress on a higher precision measurement of the n$=$2 triplet P fine structure of atomic helium

Precision measurement of the 2$^{\mathrm{3}}$P fine structure of atomic helium, when combined with precise theory, can be used to determine the value of the fine-structure constant. We report on progress towards an improved measurement using a new technique which reduces systematic effects, while improving the signal-to-noise ratio. An intense beam of 2$^{\mathrm{3}}$S metastable helium atoms is created in a hollow-cathode liquid-nitrogen-cooled DC-discharge source. The atoms are laser excited to the 2$^{\mathrm{3}}$P state and microwave transitions are driven between the 2$^{\mathrm{3}}$P states using the Ramsey method of separated oscillatory fields (SOF). Atoms which complete the SOF sequence are shelved into the 2$^{\mathrm{3}}$S m$=$-1 metastable state using laser transitions through the 3$^{\mathrm{3}}$S state. These m$=$-1 atoms can be detected with high efficiency.