Ahmed Mushtaq, Magalhães Daniel V, Bebeachibuli Aida, Müller Stella T, Alves Renato F, Ortega Tiago A, Weiner John, Bagnato Vanderlei S
Optics Laboratories, Islamabad, Pakistan.
An Acad Bras Cienc. 2008 Jun;80(2):217-52. doi: 10.1590/s0001-37652008000200002.
Cesium atomic beam clocks have been the workhorse for many demanding applications in science and technology for the past four decades. Tests of the fundamental laws of physics and the search for minute changes in fundamental constants, the synchronization of telecommunication networks, and realization of the satellite-based global positioning system would not be possible without atomic clocks. The adoption of optical cooling and trapping techniques, has produced a major advance in atomic clock precision. Cold-atom fountain and compact cold-atom clocks have also been developed. Measurement precision of a few parts in 10(15) has been demonstrated for a cold-atom fountain clock. We present here an overview of the time and frequency metrology program based on cesium atoms under development at USP São Carlos. This activity consists of construction and characterization of atomic-beam, and several variations of cold-atom clocks. We discuss the basic working principles, construction, evaluation, and important applications of atomic clocks in the Brazilian program.
在过去的四十年里，铯原子束钟一直是许多科学技术领域中高要求应用的主力军。如果没有原子钟，对物理基本定律的测试以及对基本常数微小变化的探寻、电信网络的同步以及基于卫星的全球定位系统的实现都将无法进行。光学冷却和俘获技术的采用使原子钟的精度取得了重大进展。冷原子喷泉钟和紧凑型冷原子钟也已被研发出来。冷原子喷泉钟已展示出达到10的15次方分之几的测量精度。在此，我们概述了圣保罗大学圣卡洛斯分校正在开展的基于铯原子的时间和频率计量项目。这项工作包括原子束钟的构建与特性研究，以及几种不同类型的冷原子钟。我们讨论了巴西项目中原子钟的基本工作原理、构建、评估及重要应用。
