Rydberg constant and fundamental atomic physics

A critical compilation of experimental data on spectral lines and energy levels of hydrogen, deuterium, and tritium

“…It is not clear whether this method is identical to the one used by Jennings et al [135]. Therefore, the assertion of Zhao et al [111,121] that the frequency of their reference laser was the same as measured by Jennings et al [135] cannot be verified. However, it is possible to re-calibrate the measurements of Zhao et al [111,121] using the hydrogen 2S-4P 1/2,3/2 transition frequencies accurately measured by Berkeland et al [117].…”

“…Lea et al [137], Madej et al [138], and references therein), a good reproducibility of the He-Ne-I 2 frequency standard can be achieved only if the laser is operating under conditions that are defined and controlled more strictly than it was known at the time of the experiments of Jennings et al [135] and Zhao et al [111]. The frequency stabilization method of Zhao et al [111], as described in their later paper [121] (using a third-derivative signal) is different from the current BIPM recommendations. It is not clear whether this method is identical to the one used by Jennings et al [135].…”

“…e Recalibrated using the 2S 1/2 -3P 3/2 measurement of Zhao et al [111] (see text). f Re-calibrated using the correction factor determined from the 2S-4P 1/2 3/2 frequencies measured by Zhao et al [121] and Berkeland et al [117] (see text).…”

“…Using a method similar to that for the Balmer-a components, Zhao et al [121] measured the frequencies of the 2S F=1 -4P 1/2 and 2S F=1 -4P 3/2 transitions. Applying corrections for the hfs of 2S and 4P, they obtained the fine-structure frequencies 616 520 018.02(7) MHz and 616 521 388.87 (16) MHz for the 2S-4P 1/2 and 2S-4P 3/2 transitions, respectively (the indicated uncertainties are statistical only, as quoted from Table II of Zhao et al [121]).…”

“…Applying corrections for the hfs of 2S and 4P, they obtained the fine-structure frequencies 616 520 018.02(7) MHz and 616 521 388.87 (16) MHz for the 2S-4P 1/2 and 2S-4P 3/2 transitions, respectively (the indicated uncertainties are statistical only, as quoted from Table II of Zhao et al [121]). We note that the correction for the hfs of 4P 1/2 and 4P 3/2 was estimated by Zhao et al [121] (see their Table I) to be +0.561 (30) MHz and À0.561(30) MHz, respectively. From our calculations of the hfs intervals (see Section 3.1.2), these corrections are (1/12) Â hfs(4P 1/2 ) = 0.616 MHz and (À5/24) Â hfs(4P 3/2 ) = À0.616 MHz, respectively.…”