Abstract

We report investigations with tunable VUV radiation, employing VUV generation in regions down to the cut-off wavelength of lithium fluorid crystal (~ 110 nm) by frequency tripling of tunable UV from dye laser. -Experiments on multiphoton excitation and ionization of atomic hydrogen with tunable VUV light at Lyman-α, have been carried out with the following objectives: (1) sensitive H and D atom detection by two-photon ionization i. e.$\text{1s}\underrightarrow{{}^{\text{ω}}\text{Lyα}}2\text{p}\underrightarrow{{}^{\text{ω}}\text{uv}}\text{ ion}$, (2) two-photon ionization of H with high resolution at Lyman-α to resolve the hyperfine groundstate doublet, aiming at the production of polarized protons, (3) state selective production of high Rydberg states$\left(1\text{s}\underrightarrow{{}^{\text{ω}}\text{Lyα}}\text{2p}\underrightarrow{{}^{\text{ω}}\text{uv}}\text{ ns, nd}\right)$, and their ionization, (4) Doppler line shape spectroscopy at Lyman-α applied to recoil energy and momentum distribution measurements of H and D atoms in dissociation processes. -Depending on the objective, different experimental conditions and systems have been employed, for instance atomic beam configuration, mass-spectroscopic ion detection, field ionization in cryogenetic environment, and for Doppler measurements laser induced fluorescence.

© 1982 Optical Society of America