Temperature and number evolution of cold cesium atoms inside a wall-coated glass cell

• Published in: Chinese physics B Vol. 24; no. 11; pp. 43 - 48
• Main Author: 黄家强 张建伟 王时光 王正博 王力军
• Format: Journal Article
• Language: English
• Published: 01.11.2015
• Subjects: Atomic properties; Cesium; Cold atoms; Diffusion; Evolution; Glass; Laser cooling; Walls; 中冷; 和数; 壁面; 演化过程; 电池; 瞬时温度; 铯原子; 镀膜玻璃
• ISSN: 1674-1056; 2058-3834; 1741-4199
• DOI: 10.1088/1674-1056/24/11/113701

We report an experimental study on the temperature and number evolution of cold cesium atoms diffusively cooled inside a wall-coated glass cell by measuring the absorption profile of the 62S1/2 （F = 4） →62P3/2（F= 5） transition line with a weak probe laser in the evolution process. We found that the temperature of the cold atoms first gradually decreases from 16 mK to 9 mK, and then rapidly increases. The number of cold atoms first declines slowly from 2.1 × 109 to 3.7×108 and then falls drastically. A theoretical model for the number evolution is built and includes the instantaneous temperature of the cold atoms and a fraction p, which represents the part of cold cesium atoms elastically reflected by the coated cell wall. The theory is overall in good agreement with the experimental result, and a nonzero value is obtained for the fraction p, which indicates that the cold cesium atoms are not all heated to the ambient temperature by a single collision with the coated cell wall. These results can provide helpful insight for precision measurements based on diffuse laser cooling.