Half-Axed Fusion Program

Posted by Rezwan on Sep 15, 2011 at 04:07 PM
Tools: Print | | (2) Comments

The Good News:

The article by Toni Feder reports that the US has joined the Wendelstein 7-X (W7-X) stellarator project in Greifswald, Germany, a premier fusion facility.  Part of the US contribution is manufacture of trim coils and code development to analyze trim coil results.  “The trim coils were a very much wanted missing item.  We discovered that this instrument was utterly needed and was not in the budget.” 

This is great for the W7-X project and we wish them every success.  Unfortunately, this underscores the continued erosion of non ITER fusion research.

The Bad News

The article’s subtitle sums it up, “Tight money leads to increased emphasis on tokamak plasma physics and the shuttering of some exploratory experiments.”

Redirecting fusion research away from alternatives

The move also fits with the US Department of Energy’s redirection of fusion plasma research to science relevant to ITER, the international fusion test reactor under construction in France.  Accordingly, DOE has canceled some small, non-tokamak experiments.  Edmund Synakowski, DOE’s Office of Science associate director for fusion energy sciences, describes the shift as going away from “exploring such alternative configurations for their own sake” to research that “can contribute to our understanding and optimizing the tokamak configuration and configurations closely related to it.”

US falling behind in fusion

The move to join overseas facilities also reflects the erosion of the US program in general:

US fusion scientists are glad to join the W7-X.  The US invests less in fusion research than Europe does, and US facilities are being outpaced by new experiments in Asia.  “There is a general theme to take advantage of the fusion plasma facilities abroad,” says PPPL director Stewart Prager.  “At the same time, to make progress in fusion generally, and to benefit from ITER, unquestionably the gorilla in the room, a strong US program is imperative.”

Physicists speak out in favor of alternatives

Meanwhile, though, some in the US fusion community are dismayed about the cutting of non-tokamak experiments, such as the $1.2-million-a-year Levitated Dipole Experiment at MIT.  Inspired by planetary magnetospheres, the LDX uses a central superconducting dipole to confine high-temperature plasma in steady state without large external magnets.  Columbia University’s Michael Mauel, a principal investigator on the experiment, told FESAC in March that “discovery research like LDX is important to the vitality of our field because it is not a tokamak or a stellarator.”

A couple of researchers would not go on record criticizing the cancellations for fear that DOE would retaliate in future funding competitions. 

But Tom Jarboe, a plasma physicist at the University of Washington, Seattle, where the TCS (Translation, Confinement, and Sustainment field-reversed configuration experiment) was cut says, “I think that any experiment that does not have a toroidal field was axed.  We should explore a lot of ideas.  The tokamak is not to the point that we know it will make economical fusion.” 

Stephen Dean, director of the nonprofit Fusion power Associates, puts it more strongly:  “The damage to the US innovative confinement concepts fusion program by terminating the LDX and other non-tokamak experiments far exceeds any benefit that might accrue from the minimal support provided to Wendelstein.”