TY - JOUR AU - Venturi, V AU - Tiesinga, Eite AU - Williams, Carl C2 - Physical Review A (Atomic, Molecular and Optical Physics) DA - 2004-01-01 LA - en PB - Physical Review A (Atomic, Molecular and Optical Physics) PY - 2004 TI - Ballistic Expansion and Collisions in the Cs Atomic Fountain Clock ER -