Lamplight Stabilization for GPS Rb Atomic Clocks via RF-Power Control

Abstract

Recent evidence indicates that the signal-in-space user-range-error (SIS-URE) for GPS is strongly influenced by the satellite atomic clock's rubidium (Rb) lamplight intensity jumps. Following a proposal by Bloom and Bell, we have implemented RF-power control of an RF-discharge lamp of the type employed in Rb atomic frequency standards (RAFS). Since Rb lamplight intensity jumps are mapped onto the clock's output frequency via the light-shift effect, stabilization of the Rb light emitted by the lamp has the potential to significantly improve the RAFS' long-term frequency stability, and hence the GPS SIS-URE. Here, we not only demonstrate that RF-power control of the discharge lamp is possible, but also that by employing such control the fluctuations in Rb lamplight intensity can be reduced by orders of magnitude, providing a pathway for significant improvement in global navigation satellite systems.

Characteristics of the space-borne rubidium atomic clocks for the BeiDou III navigation satellite system

“…利 用数字电路设计微波链, 可将相位噪声对铷原子钟稳 定度的影响降至10 −14 /τ 1/2 量级 [16,17] . Huang等人 [18] 提出 了一种谱灯光强控制方案, 这有助于进一步改善铷原 子钟的长稳. 根据这些进展, 我们预期铷原子钟频率 稳定度还可以继续得到提升.…”

Efficient Selective Adsorption of Rubidium and Cesium from Practical Brine Using a Metal–Organic Framework-Based Magnetic Adsorbent

“…Rubidium (Rb) and cesium (Cs), members of the three rare resources, are used in high technology fields such as communication, medical treatment, aviation, and new energy and materials − owing to their excellent chemical activity and photoelectric effect. They are used in various fields such as atomic clocks, magnetic fluid generators, and ion thrusters with the development of science and technology. , In addition, 137 Cs, a fission product of uranium, is a major radionuclide in wastewater .…”