Single-event high-compression inertial confinement fusion at low temperatures compared with two-step fast ignitor

Abstract

Compression of plasmas with laser pulses in the 10-kJ range produced densities in the range of 1000 times that of the solid state, where however the temperatures within a few hundred eV were rather low. This induced the fast ignitor scheme for central or peripheral deposition of some 10-kJ ps laser pulses on conventional $n_{\rm s}$-precompressed DT plasma of 3000 times solid-state density. We present results where the ps ignition is avoided and only a single-event conventional compression is used. Following our computations of volume ignition and the excellent agreement with measured highest fusion gains of volume compression, we found conditions where compression to 5000 times that of the solid state and by using laser pulses of 10 MJ produce volume ignition with temperatures between 400 and 800 eV only for high-gain volume ignition.

Collective alpha particle stopping for reduction of the threshold for laser fusion using nonlinear force driven plasma blocks

“…1). This result of the much shorter stopping length of the reaction products in laser fusion was the reason of the strong reheats in laser irradiated fusion pellets for DT at fully detailed inclusion of the adiabatic expansion dynamics of the spherical plasmas leading to the discovery of the volume ignition (Hora & Ray, 1978;Hora et al, 2003;Hora, 2007). This was confirmed later by Kirkpatrick and Wheeler (1981)-where the cooperation with John A. Wheeler should be underlined-and numerous other authors (Tahir & Long, 1983;Tahir, 1986Tahir, , 1994Basko, 1990;Martinez-Val et al, 1994;Atzeni, 1995) where the robustness of volume ignition was underlined by Lackner et al (1994) against spark ignition (Lindl, 1994) with nearly the same fusion gains, and using the ideal and natural adiabatic hydrodynamics of the reacting DT plasma was shown that only this volume process arrived at the highest measured fusion gains (Hora et al, 1998.…”

Contributions on Laser Driven Inertial Confinement Fusion

“…Still as an alternative to fast ignition and using lower temperatures resulting from Azechi et al, it was possible that we recalled our volume ignition computations where at sufficiently large laser pulse energies and sufficient high compression, the ignition temperature could well be near 500 eV and even lower. One result is that if compression could be increased from 2000 to 5000 times the solid DT and if a red smoothed neodymium glass laser pulse of 10 MJ (twice that of NIF) is incident that the gang of 36 (fusion produced electric energy per incident laser energy) can be achieved by volume ignition [36] . This should be compared with the discussed project of ITER where not before 2015, 500 second long pulses may produce a gain of 0.3 fusion produced electric energy per input electricity [36a] .…”

Ideal energy source by Mark Oliphant's beam fusion

“…For very large scale laser fusion using few MJ laser pulses including smoothing for working with long wave lengths, this should not be too problematic if volume ignition is used for direct drive and not spark ignition. It has been calculated by Hora et al (2003) Energy Eo(J) in Pellet density, volume ignition will reach the range where the bremsstrahlung re-absorption results in ignition temperatures of only a few hundred eV. This would be sufficient for a one step laser fusion reactor based on robust adiabatic volume compression as was successful with the hitherto highest laser fusion gains, but avoiding the problems of spark ignition.…”

“…This would be sufficient for a one step laser fusion reactor based on robust adiabatic volume compression as was successful with the hitherto highest laser fusion gains, but avoiding the problems of spark ignition. This would at least be a conservative solution for laser fusion based on well-established technology (Hora et al 2003). Broad research is aimed at spark ignition (Lindl 1994) where the fusion efficiency may be two times higher than with the volume ignition concept (Hora et al 1998), but where the problems with compression symmetry and instabilities are much more difficult.…”