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Updated: Jun 20, 2026

Ultrafast Time-resolved Near-IR Stimulated Raman Measurements of Functional π-conjugate Systems
Published on: February 10, 2020
Measurement of the He 1s2s (1)S(0) isotopic shift using a tunable VUV anti-Stokes light source
Abstract:
We describe a high-resolution, vacuum-ultraviolet spectroscopic technique based on a tunable, narrow-band, VUV, spontaneous anti-Stokes light source. The technique was used to measure the absolute energies of the 1s2s (1)S(0) states of (3)He and (4)He; the 1s2s (1)S(0) level of (3)He is 7.8 +/- 0.5 cm(-1) below that of (4)He.
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