Review about acceleration of plasma by nonlinear forces from picoseond laser pulses and block generated fusion flame in uncompressed fuel

Abstract

In addition to the matured "laser inertial fusion energy" with spherical compression and thermal ignition of deuteriumtritium (DT), a very new alternative for the fast ignition scheme may have now been opened by using side-on block ignition aiming beyond the DT-fusion with igniting the neutron-free reaction of proton-boron-11 (p-11 B). Measurements with laser pulses of terawatt power and ps duration led to the discovery of an anomaly of interaction, if the prepulses are cut off by a factor 10 8 (contrast ratio) to avoid relativistic self focusing in agreement with preceding computations. Applying this to petawatt (PW) pulses for Bobin-Chu conditions of side-on ignition of solid fusion fuel results after several improvements in energy gains of 10,000. This is in contrast to the impossible laser-ignition of p-11 B by the usual spherical compression and thermal ignition. The side-on ignition is less than ten times only more difficult than for DT ignition. This is essentially based on the instant and direct conversion the optical laser energy by the nonlinear force into extremely high plasma acceleration. Genuine two-fluid hydrodynamic computations for DT are presented showing details how ps laser pulses generate a fusion flame in solid state density with an increase of the density in the thin flame region. Densities four times higher are produced automatically confirming a Rankine-Hugoniot shock wave process with an increasing thickness of the shock up to the nanosecond range and a shock velocity of 1500 km/s which is characteristic for these reactions.

Propagation of ion shock in solid DT target with nonlinear force-driven plasma blocks

“…It is important to mention that our result of a compression by a factor 4 at the shock front is exactly what was reported with the results of computations (34) in agreement with the Rankine-Hugoniot theory. Also, the same results were reported by the other authors but with different derivations.…”

“…From Equation (34), it is evident that the density increase is also small, so that V 1 ≈ V 0 , and the sound speeds are almost equal, so that C s,1 ≈ C s,0 . It becomes obvious from Equations (62) and (63) that in this case, u ion-shock ≈ C s,0 ≈ C s,1 ≈ u block .…”

Low energy measurements of the B10(p,α)Be7 reaction

“…This reaction has two primary advantages over the 3 He( 3 He, 2p) 4 He reaction. First, it does not require 3 He, which is mostly produced as a decay product of tritium 3 H [3,4] and second, 11 B is a naturally abundant and inexpensive fuel stock.…”

“…While the 11 B+p fusion system has already been considered as a potential energy source in traditional plasma systems [5][6][7] and for colliding beam reactors [8], recent observations of aneutronic fusion reactions on laser picosecond plasmas [9] have motivated the discussion of other possible applications. One such application uses the 11 B(p, 2α) 4 He reaction for laser driven hot pulsed * Michael.C.…”

“…One such application uses the 11 B(p, 2α) 4 He reaction for laser driven hot pulsed * Michael.C. Wiescher.1@nd.edu plasma systems [10][11][12], and another proposes laser jet propulsion systems for long distant space travel [13]. The optimal energy range for a 11 B+p fusion system is between E c.m.…”