Recombination during expansion of ultracold plasma  

作　　者：赵建明 张临杰 冯志刚 李昌勇 贾锁堂 

机构地区：[1]State Key Laboratory of Quantum Optics and Quantum Optics Devices,College of Physics and Electronics Engineering,Shanxi University

出　　处：《Chinese Physics B》2010年第4期203-207,共5页中国物理B（英文版）

基　　金：Project supported by the National Basic Research Program of China (Grant No. 2006CB921603);the National Natural Science Foundation of China (Grant Nos. 60978018,60978001,10934004 and 60778008);the Foundation of the Ministry of Educationof China;the Science Foundation for Returned Scholars of Shanxi Province of China

摘　　要：Signals of ultracold plasma are observed by two-photon ionization of laser-cooled caesium atoms in a magnetooptical trap. Recombination of ions and electrons into Rydberg atoms during the expansion of ultracold plasma is investigated by using state-selective field ionization spectroscopy. The dependences of recombination on initial electron temperature （1 70 K） and initial ion density （-10^10 cm-3） are investigated. The measured dependence on initial ion density is N^1.547±0.004 at a delay time of 5μs. The recombination rate rapidly declines as initial electron temperature increases when delay time is increased. The distributions of Rydberg atoms on different values of principal quantum number n, i.e. n = 30-60, at an initial electron temperature of 3.3 K are also investigated. The main experimental results are approximately explained by the three-body recombination theory.Signals of ultracold plasma are observed by two-photon ionization of laser-cooled caesium atoms in a magnetooptical trap. Recombination of ions and electrons into Rydberg atoms during the expansion of ultracold plasma is investigated by using state-selective field ionization spectroscopy. The dependences of recombination on initial electron temperature （1 70 K） and initial ion density （-10^10 cm-3） are investigated. The measured dependence on initial ion density is N^1.547±0.004 at a delay time of 5μs. The recombination rate rapidly declines as initial electron temperature increases when delay time is increased. The distributions of Rydberg atoms on different values of principal quantum number n, i.e. n = 30-60, at an initial electron temperature of 3.3 K are also investigated. The main experimental results are approximately explained by the three-body recombination theory.

关 键 词：recombination ultracold plasma Rydberg atoms 

分 类 号：O53[理学—等离子体物理]