The Z-pinch, perhaps the oldest subject in plasma physics, has achieved a remarkable renaissance in recent years, following a few decades of neglect due to its basically unstable MHD character. Using wire arrays, a significant transition at high wire number led to a great improvement in both compression and uniformity of the Z-pinch. Resulting from this the Z-accelerator at Sandia at 20 MA in 100 ns has produced a powerful, short pulse, soft x-ray source >230 TW for 4.5 ns) at a high efficiency of ~15%. This has applications to inertial confinement fusion. Several hohlraum designs have been tested. The vacuum hohlraum has demonstrated the control of symmetry of irradiation on a capsule, while the dynamic hohlraum at a higher radiation temperature of 230 eV has compressed a capsule from 2 mm to 0.8 mm diameter with a neutron yield >3 × 1011 thermal DD neutrons, a record for any capsule implosion. World record ion temperatures of >200 keV have recently been measured in a stainless-steel plasma designed for Kα emission at stagnation, due, it was predicted, to ion-viscous heating associated with the dissipation of fast-growing short wavelength nonlinear MHD instabilities. Direct fusion experiments using deuterium gas-puffs have yielded 3.9 × 1013 neutrons with only 5% asymmetry, suggesting for the first time a mainly thermal source. The physics of wire-array implosions is a dominant theme. It is concerned with the transformation of wires to liquid-vapour expanding cores; then the generation of a surrounding plasma corona which carries most of the current, with inward flowing low magnetic Reynolds number jets correlated with axial instabilities on each wire; later an almost constant velocity, snowplough-like implosion occurs during which gaps appear in the cores, leading to stagnation on the axis, and the production of the main soft-x-ray pulse. These studies have been pursued also with smaller facilities in other laboratories around the world. At Imperial College, conical and radial wire arrays have led to highly collimated tungsten plasma jets with a Mach number of >20, allowing laboratory astrophysics experiments to be undertaken. These highlights will be underpinned in this review with the basic physics of Z-pinches including stability, kinetic effects, and finally its applications.

A review of the dense Z-pinch

http://www.fusion.ucla.edu/abdou/abdou%20publications/2006/FED-v81-SawanPhysics.pdf

Physics and technology conditions for attaining tritium self-sufficiency for the DT fuel cycle

Recent progress in laser driven implosion is reviewed. Improvements in the uniformity of irradiation by laser beams on fuel pellets have achieved quantitative progress in implosion performance. The recent results of the direct drive–central ignition experiments give us confidence in achieving fusion ignition, burning and energy gain using a multi-beam megajoule laser with full implementation of beam smoothing techniques. Fast ignition research is also reviewed, which could give us a higher energy gain with lower laser energy. The science and technology of laser fusion power plants are beginning to attract wider attention, as forming the road map to achieve commercial power plants for cleaner, safer and abundant fusion energy.Corrections were made to this article on 28 April 2004

http://iopscience.iop.org/article/10.1088/0034-4885/67/3/R04/pdf

Laser driven inertial fusion energy: present and prospective

http://www.ralphmoir.com/media/fur_icenes_2007.pdf

A Road Map for the Realization of Global-scale Thorium Breeding Fuel Cycle by Single Molten-Fluoride Flow

This paper reviews work on flashlamp-pumped solid state lasers and discusses diode-pumped solid state lasers, the Mercury laser in particular. It also discusses ICF lasers beyond Mercury.

/pdf/diode-pumped-solid-state-laser-drivers-for-inertial-fusion-2mdsvqa1zu.pdf

Diode-pumped solid-state laser drivers for inertial fusion energy

Enhanced safety and performance improvements have been made to the liquid-wall HYLIFE reactor, yielding the current HYLIFE-II conceptual design. Liquid lithium has been replaced with a neutronically thick array of flowing molten-salt jets (Li[sub 2]BeF[sub 4] or Flibe), which will not burn, has a low tritium solubility and inventory, and protects the chamber walls, giving a robust design with a 30-yr lifetime. The tritium inventory is 0.5 g in the molten salt and 140 g in the metal of the tube walls, where it is less easily released. The 5-MJ driver is a recirculating induction accelerator estimated to cost $570 million (direct costs). Heavy-ion targets yield 350 MJ, six times per second, to produce 940 MW of electrical power for a cost of 6.5 cents/kW[center dot]h. Both larger and smaller yields are possible with correspondingly lower and higher pulse rates. When scaled up to 1934 MW (electric), the plant design has a calculated cost of electricity of 4.5 cents/kW[center dot]h. The design did not take into account potential improved plant availability and lower operations and maintenance costs compared with conventional power plant experience, resulting from the liquid wall protection. Such improvements would directly lower the electricity cost figures. For example,more » if the availability can be raised from the conservatively assumed 75% to 85% and the annual cost of component replacement, operations, and maintenance can be reduced from 6% to 3% of direct cost, the cost of electricity would drop to 5.0 and 3.9 cents/kW[center dot]h for 1- and 2-GW (electric) cases. 50 refs., 15 figs., 3 tabs.« less

HYLIFE-II: A Molten-Salt Inertial Fusion Energy Power Plant Design — Final Report

Conceptual DT and DD fusion reactors are discussed based on magnetic confinement with the high-plasma-density Z-pinch. The reactor concepts have no "first wall", the fusion neutrons and plasma energy being absorbed directly into a surrounding lithium vortex blanket. Efficient systems with low re-circulated power are projected, based on a flow-through pinch cycle for which overall Q values can approach 10. The conceptual reactors are characterized by simplicity, small minimum size (100 MW(e)) and by the potential for minimal radioactivity hazards.

https://iopscience.iop.org/article/10.1088/0029-5515/17/5/004/pdf

A conceptual fusion reactor based on the high-plasma-density Z-pinch

A Compact Torus Accelerator (CTA) is used to accelerate a Compact Torus (CT) to 35 MJ kinetic energy which is focused to a 20 mm diameter where its kinetic energy is converted to a shaped x-ray pulse of 30 MJ. The capsule yield with a prescribed radiation profile is calculated to be (gain 60 times 30 MJ) 1.8 GJ. Schemes for achieving this profile are described. The CT is accelerated in a length of 30 m within an annulus of 150 mm ID and 300 mm OD where the maximum magnetic field is 28 T. A 2.5 m conical taper reduces the mean diameter of the CT from 225 mm to 20 mm. The conical section is made out of solid Li{sub 2}BeF{sub 4}. The target with its frozen conical guide section is accurately placed at the end of the accelerator about once per second. The reactor called HYLIFE uses liquid jets to attenuate blast effects including shrapnel from the shattered conical guide section and radiation so that the vessel is expected to last 30 years. The calculated cost of electricity is estimated (in constant 1988 dollars) to be about 4.8 cents/kW {center_dot} h compared to the future cost of more » nuclear and coal of 4.3 to 5.8 cents/kW {center_dot} h. The CT driver contributes 17% to the cost of electricity. Present CT's make 2 x 10{sup 8} W/cm{sup 2}; the goal of experiments in progress is 10{sup 11} W/cm{sup 2} with further modifications to allow 10{sup 12}W/cm{sup 2}, whereas the reactor requires 10{sup 15} W/cm{sup 2} in a shaped pulse. « less

/pdf/compact-torus-accelerator-driven-inertial-confinement-fusion-4b1bceq261.pdf

Compact Torus Accelerator Driven Inertial Confinement Fusion Power Plant HYLIFE-CT

Fusion reactor first-wall cooling for very high energy fluxes

A new integrated power and breeding blanket is described. The blanket incorporates features that make it suitable for synthetic fuel production. It is matched to the thermal and electrical requirem...

M. A. Hoffman

Papers

HYLIFE-II: A Molten-Salt Inertial Fusion Energy Power Plant Design — Final Report

A conceptual fusion reactor based on the high-plasma-density Z-pinch

Compact Torus Accelerator Driven Inertial Confinement Fusion Power Plant HYLIFE-CT

Fusion reactor first-wall cooling for very high energy fluxes

The Gas-Cooled, Li2O Moderator/Breeder Canister Blanket for Fusion-Synfuels