Abstract
We have observed the 1 1S-2 1P resonance line of He4 at 58.4 nm (linewidth 0.3 cm-1) in a laser-atomic-beam experiment. The coherent radiation is produced by fifth-harmonic generation of UV light from a frequency-doubled, pulsed dye laser at 584 nm in a pulsed expansion of acetylene gas. The frequency of the fundamental radiation is calibrated against the iodine absorption spectrum, resulting in a transition frequency of 171 134.89(3) cm-1. From this value a Lamb shift for the ground state of +1.38(3) cm-1 is extracted, in good agreement with the theoretical value of +1.3745 cm-1 © 1993 The American Physical Society.
Original language | English |
---|---|
Pages (from-to) | 1690-1692 |
Journal | Physical Review Letters |
Volume | 71 |
Issue number | 11 |
DOIs | |
Publication status | Published - 1993 |