Wurden thinks his team has a shot at beating ITER to the break-even finish line, but only if he can scrounge up a little more cash. “We can’t do it with the funding we have now,” he says. “The Department of Energy sponsors all the magnetic fusion research in the country. Alternate projects like ours are at best about 10 percent of the budget, maybe $20 million divided among 10 universities and a couple of national labs.”
Even if NIF beats canned fusion to break-even, Wurden thinks his approach will be more practical in the long run. NIF’s lasers currently fire just two or three times a day. It takes 30 minutes just to position the fuel capsule. A commercial laser fusion reactor might have to fire about 15 times a second.
For a reality check on Shiva Star, I spoke with Jaeyoung Park, an experimental physicist who has taken leave from Los Alamos to join a small team in Santa Fe that is pursuing its own fusion research. His biggest concern is that Wurden may not be able to contain the deuterium plasma long enough. “It’s very difficult to squeeze the plasma uniformly—the squeezing has to be fast and furious,” Park says. “And heat losses might make it impossible for the plasma to achieve the high temperatures needed for fusion. But Glen is planning some significant experiments, and even if the first ones fail, the results should tell us something important.”
Wurden acknowledges those problems and brings up another for good measure. “How do you control millions of amps of current at thousands of volts?” he asks. “The switches we use are fancy things that work under high voltage. We can switch high currents maybe 20 times a day.” But a working fusion reactor based on Shiva Star would need to handle such currents once every 10 seconds.
Canada’s General Fusion is also working to Magnetized Target Fusion but with a different approach
General Fusion’s magnetized target fusion reactor will incorporate a multipurpose liquid-metal lining to produce tritium, protect equipment from damage, and extract the heat that generates energy. The company hopes to achieve break-even by 2013