concept, with leakage at the absolute lower limit allowed by theory, could only reach Q=1.2. This made these designs largely useless for power production, and Hirsch demanded that this be improved if the program were to continue. This problem became known as "Q-enhancement". In March 1976, the Livermore team decided to organize a working group on the topic of Q-enhancement at the October 1976 international fusion meeting in Germany. Over the July 4th weekend, Fowler and Post came up with the idea of the tandem mirror, a system consisting of two mirrors at either end of a large chamber that held large amounts fusion fuel at lower magnetic pressure. They returned to LLNL on Monday to find the idea had been developed independently by a staff physicist, Grant Logan. They brought further developed versions of these ideas to Germany to find a Soviet researcher proposing exactly the same solution. Upon their return from the meeting, Dean met with the team and decided to shut down the Baseball II system and direct its funding to a tandem mirror project. This emerged as the Tandem Mirror Experiment, or TMX. The final design was presented and approved in January 1977. Construction of what was then the largest experiment at Livermore was completed by October 1978. By July 1979, experiments were demonstrating that TMX was operating as expected. Thermal barriers and MFTF Even before the tandem mirror concept emerged, what was by this time the Department of Energy had agreed to fund the construction of a much larger mirror known as the Mirror Fusion Test Facility (MFTF). At the time, the plan for MFTF was to simply be the largest yin-yang magnet anyone could figure out how to build. With the success of the TMX concept, the design was modified to become MFTF-B, using two of the largest yin-yang magnets anyone could figure out how to build in an enormous tandem configuration. The goal was to meet Q=5. Through late 1978 when the teams began to actually consider the steps in scaling up the TMX, it became clear that it simply would not hit the required goals. In January 1979, Fowler stopped the work, stating that some improvement would have to be found. During experiments on the TMX, it was found to everyone's surprise that the law introduced by Lyman Spitzer in the 1950s was not holding; in TMX at least, electrons on any