Branching ratio measurements for GeI and GeII

A high resolution Fourier-transform spectrometer was used to measure branch ing ratios for 5s-5p, 4d-6s, 6s-6p, 5s-6p, 4d-6p, 4d-7p transitions in neut ral germanium and 4d-4f, 4p(2)-4f, 4p(2)-5p, 5s-5p, 4p(2)-4p, 4d-6p, 4p(2)- 6p, 4d-5f, 4p(2)-5f, 4d-7p, 4p(2)-7p, of singly ionized germanium. Measurem ents were performed with a hollow cathode as a light source. Spectral lines intensities were measured in a spectral range from 200 to 3500 nm. Absolut e transition probabilities for some Ge II lines were obtained using experim ental lifetime values for the 4s(2)4f(2)F(5/2), F-2(7/2) and 4s(2)5p(2)P(1/ 2), P-2(3/2) levels. Our results for transitions in neutral germanium show that some infrared lines, so far overlooked in spectral analyses, give a st rong 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.