Abstract
Experiments were carried out on the TRX field reversed theta pinch in which s, the number of ion gyroradii between the magnetic null and the separatrix of a field reversed configuration, was increased significantly compared with previous experiments where s ≤ 2. Sustained values of s > 4 were obtained in hydrogen discharges with configuration lifetimes as long as twenty tilt growth times, where the calculated growth rate reduction due to ion kinetic effects has been accounted for.