Collisional cross-sections measurement of ultracold caesium Rydberg states Zhi-Gang Feng, Lin-Jie Zhang, Hao Zhang, Jian-Ming Zhao, Chang-Yong Li and Suo-Tang Jia EPL, 92 1 (2010) 13002 Published online: 19 October 2010 DOI: 10.1209/0295-5075/92/13002