explosive). Some analyses of fatigue and nucleonics limits of possible chamber materials and some experimental studies relevant to thick liquid wall reactor chambers have been carried out,126 but much work is yet to be done here. Design and execution of a hydrodynamically equivalent experiment that could be conducted in a smaller “scaled” chamber at a much-reduced energy level should be part of the Phase 1 research program (see Table 2-3). This research would benefit heavy-ion fusion as well. If there is no technically viable solution to the reactor chamber problem at 10 GJ that is also economically viable, then pulsed-power fusion researchers will have to reoptimize their system design at a lower energy per pulse and a higher repetition rate than 0.1 Hz. Thus, the technical and economic feasibility of the 10 GJ yield system should be evaluated as early in Phase 1 as possible.
Given the state of development of linear transformer drivers (LTDs) (see Figures 2.11 and 2.12),127 the technology challenges associated with the pulsed-power system appear to be much less daunting than those discussed above. Nevertheless, the technology must still be demonstrated to be extremely reliable, as there would be hundreds of thousands of switches and a million capacitors in a pulsed-power reactor driver.128 Furthermore, the driver must be demonstrated to be compatible with using recyclable transmission lines, including their potential failure modes (e.g., sparking due to poor connections).
Many of the scientific issues having to do with MagLIF target physics can be addressed using existing facilities in the next 5 years, and many will be investigated as part of the NNSA-sponsored (single-pulse) ICF program at SNL. It is anticipated that this program will be funded at an estimated level of $6.8 million to $8.5 million per year through 2017.129 All pulsed-power approaches call for recyclable transmission lines and extremely high-yield pulses at a repetition rate of ~0.1 Hz, and these requirements make some of the necessary research and development for pulsed-power IFE unique. The high repetition rate driver technology needed for fusion via pulsed power is currently receiving development funding at the rate of $1.5 million to $3.3 million per year,130 and steady progress is being made.
The engineering feasibility challenges of MagLIF should be addressed early in the program, along with the target physics, to assess the viability of pulsed-power fusion. To do this, new funding would be required starting in 2013 at the level
127 W. Stygar, SNL, “Conceptual Design of Pulsed Power Accelerators for Inertial Fusion Energy,” Presentation to the committee on April 1, 2011.
128 J.T. Cook, G.E. Rochau, B.B. Cipiti, C.W. Morrow, S.B. Rodriguez, C.O. Farnum, et al., 2006, Z-inertial fusion energy: Power plant, SAND2006-7148.
129 M. Cuneo, personal communication to committee member D. Hammer on November 2, 2011.