Former director of the U.S. fusion energy program Robert L. Hirsch advocated moving research efforts to “a much cleaner fusion reaction”—hydrogen-boron (pB11)—in a letter to the editor published by Physics Today, the widely-read popular journal for the American Physical Society. In a major contribution to the debate on the direction of governmental fusion research programs, published in the journal’s October issue, Dr. Hirsch sharply criticized the present governmental focus on the tokamak and especially the huge ITER project.
Hirsch, who headed the U.S. fusion energy program in the 1970’s, pointed out that as early as 1994, studies indicated that the tokamak would be 60 times as massive as a fission reactor core of the same power, and thus far more expensive. Given the fundamental problems of huge size and cost and the radioactivity induced by the deuterium-tritium (DT) fuel, “one can only guess at why ITER continues to be built”, Hirsch wrote.
Instead of continuing to focus on tokamaks and DT fuel Hirsch contends that “moving to a much cleaner fusion reaction would seem appropriate. Of particular interest is the proton and boron-11 reaction, which involves significantly more challenging physics but produces no neutrons directly. The absence of neutrons would largely eliminate the risks due to radioactivity and thereby dramatically enhance economics, regulatory simplicity, and public acceptance.” He points out that, “Thankfully, a few privately funded projects in the U.S. and elsewhere are pursuing p–11B”. Among those projects is of course LPPFusion. (In December, 2013 Dr. Hirsch headed a four-scientist review committee that concluded that LPPF’s efforts deserve “a much higher level of investment … based on their considerable progress to date.”
Physics Today solicited a reply to Dr. Hirsch’s letter from Steven Crowley, former CEO of the UK Atomic Energy Authority. Dr. Crowley, however, while defending ITER and tokamaks, did not respond to Dr. Hirsch’s alternative of pB11 approaches. The exchange in such a prominent publication is likely to spur further debate within the physics community on aneutronic fusion and the overall allocation of government fusion research efforts.