Aging studies on micro-fabricated alkali buffer-gas cells for miniature atomic clocks
| Résumé |
We report an aging study on micro-fabricated alkali vapor cells
using neon as a buffer gas. An experimental atomic clock setup is
used to measure the cell's intrinsic frequency, by recording the
clock frequency shift at different light intensities and
extrapolating to zero intensity. We find a drift of the cell's
intrinsic frequency of
(−5.2 ± 0.6) × 10−11/day and
quantify deterministic variations in sources of clock frequency
shifts due to the major physical effects to identify the most
probable cause of the drift. The measured drift is one order of
magnitude stronger than the total frequency variations expected
from clock parameter variations and corresponds to a slow reduction
of buffer gas pressure inside the cell, which is compatible with the
hypothesis of loss of Ne gas from the cell due to its permeation
through the cell windows. A negative drift on the intrinsic cell
frequency is reproducible for another cell of the same type. Based
on the Ne permeation model and the measured cell frequency drift,
we determine the permeation constant of Ne through borosilicate
glass as (5.7 ± 0.7) × 10−22 m2
s−1 Pa−1 at 81 °C. We propose this method
based on frequency metrology in an alkali vapor cell atomic clock
setup based on coherent population trapping for measuring
permeation constants of inert gases. The authors gratefully acknowledge fruitful discussions with M. Pellaton (Université de Neuchâtel) and S. Karlen (CSEM SA, Neuchâtel, Switzerland) on buffer gas permeation, Y. Pétremand (CSEM) for providing the vapor cells, and D. Varidel (Université de Neuchâtel) for support with the H-maser reference. This work was funded by the Swiss National Science Foundation (FNS) and co-financed by the Swiss Commission for Technology and Innovation (CTI) |
| Mots-clés |
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| Citation | S. Abdullah, et al., "Aging studies on micro-fabricated alkali buffer-gas cells for miniature atomic clocks," Applied Physics Letters, vol. 106, p. 1-2, Apr. 2015. |
| Type | Article de périodique (Anglais) |
| Date de publication | 22-4-2015 |
| Nom du périodique | Applied Physics Letters |
| Volume | 106 |
| Pages | 1-2 |
| URL | https://doi.org/10.1063/1.4919009 |