Branching Ratio Measurements for Ge I and Ge II

A high resolution Fourier-transform spectrometer was used to measure branching ratios for 5s-5p, 4d-6s, 6s-6p, 5s-6p, 4d-6p, 4d-7p transitions in neutral germanium and 4d-4f, 4p$\text{}^{2}$-4f, 4p$\text{}^{2}$-5p, 5s-5p, 4p$\text{}^{2}$-4p, 4d-6p, 4p$\text{}^{2}$-6p, 4d-5f, 4p$\text{}^{2}$-5f, 4d-7p, 4p$\text{}^{2}$-7p of singly ionized germanium. Measurements were performed with a hollow cathode as a light source. Spectral lines intensities were measured in a spectral range from 200 to 3500 nm. Absolute transition probabilities for some Ge II lines were obtained using experimental lifetime values for the 4s$\text{}^{2}$4f$\text{}^{2}$F$\text{}_{5}\text{}_{/}\text{}_{2}$ ,$\text{}^{2}$F$\text{}_{7}\text{}_{/}\text{}_{2}$ and 4s$\text{}^{2}$5p$\text{}^{2}$P$\text{}_{1}\text{}_{/}\text{}_{2}$ ,$\text{}^{2}$P$\text{}_{3}\text{}_{/}\text{}_{2}$ levels. Our results for transitions in neutral germanium show that some infrared lines, so far overlooked in spectral analyses, give a strong contribution to Ge spectrum. Our transition probabilities obtained for Ge II lines are lower than all other experimental and theoretical results, in one case even by an order of magnitude.