Previous toroidal electron trap experiments
Experiments have been few and far apart
- Daugherty et al, 1969 (_= 80 _s)
- John, Avinash, Khirvadkar et al, 1991-1993 (_~ 50 _s)
- Stoneking, 2000- (bent Penning trap - not fully toroidal)
None have shown the long confinement times predicted by theory
- _ >> 1 s according to theory
Neutral pressures were in the 10-7 Torr range
- Neutral drag is expected to dominate radial transport completely at such pressures (deGrassie and Malmberg, 1980) but does not fully explain the low confinement times in these devices