The history of the magnetic-mirror approach to a fusion reactor is primarily the history of our understanding and control of several crucial physics issues, coupled with progress in the technology of heating and confining a reacting plasma. The basic requirement of an MHD-stable plasma equilibrium was achieved following the early introduction of minimum-B multipolar magnetic fields. In refined form, the same magnetic-well principle carries over to our present experiments and to reactor designs. The higher frequency microinstabilities, arising from the non-Maxwellian particle distributions inherent in mirror machines, have gradually come under control as theoretical prescriptions for distribution functions have been applied in the experiments. Even with stability, the classical plasma leakage through the mirrors posed a serious question for reactor viability until the principle of electrostatic axial stoppering was applied in the tandem mirror configuration. Experiments to test this principle successfully demonstrated the substantial improvement in confinement predicted. Concurrent with advances in mirror plasma physics, development of both high-power neutral beam injectors and high-speed vacuum pumping techniques has played a crucial role in ongoing experiments. Together with superconducting magnets, cryogenic pumping, and high-power radiofrequency heating, these technologies have evolved to a level that extrapolates readily to meet the requirements of …

The 24'' H and V Duct and related piping outside the LOFT containment and connected to containment penetration S-12A were analyzed to ASME Section III, Subsection NC (Class 2) criteria. The duct is part of the Containment Isolation System. The model considered the duct from the containment O.D. outward through the second isolation valve. Results of this analysis show that this section of the line will meet Class 2 requirements without modification.

Line 2''-LS-120-AB outside containment penetration S-1A was analyzed to ASME Section III, Subsection NC (Class 2) criteria. The line is part of the LOFT Containment Isolation System. The model considered the line from the penetration outward through the second isolation valve. Results of the analysis show that this section of the line meets Class 2 requirements without modification.

A stress analysis was performed on the 4''-IW-179-AB pipe system outside containment penetration S-5B. Deadweight, thermal expansion, and seismic loads were considered. The results indicate that this piping will meet ASME Section III, Class 2 requirements.