Advanced scheme for high-yield laser driven nuclear reactions

Abstract

The use of a low contrast nanosecond laser pulse with relatively low intensity (3 × 10 16 W cm -2 ) allowed enhancing the yield of induced nuclear reactions in advanced solid targets. In particular the "ultraclean" proton-boron fusion reaction, producing energetic alpha-particles without neutron generation, was chosen. A spatially well-defined layer of boron dopants in a hydrogenenriched silicon substrate was used as target. The combination of the specific target geometry and the laser pulse temporal shape allowed the production of an enormous yield of alpha-particles around 10 9 per steradian. This result can be ascribed to the nonlinear interaction of the long laser pulse with the expanding plasma and to the optimal target geometry and composition.

Fusion energy using avalanche increased boron reactions for block-ignition by ultrahigh power picosecond laser pulses

“…Combining the experimental result of most exceptionally high gains of proton-boron (HB11) fusion Picciotto et al, 2014;Margarone et al, 2015) based on the concluded avalanche mechanisms (Hora et al,. 2014b;2015) and evaluated now in more details, with the results of >PW-ps laser-driven block ignition (Hora et al, 2010;Lalousis et al, 2014) was leading to a first step of producing ultraclean GJ fusion energy possibly by 30 kJ laser irradiation.…”

“…A convincing and very transparent result (Labaune et al, 2013) produced more than 10 6 reactions though only a complicated combination of laser-driven directed particle beams with a secondary laser-target interaction was used. After this breakthrough, the measurement of 10 9 /sr reactions Margarone et al, 2015) was achieved. These measurements were a straightforward laser-fusion result by a unique combination of one of the largest European lasers, the PALS iodine laser at Prague, with the use of a very unusual laser-irradiated target.…”

“…The other unusual ingredient of the experiment Margarone et al, 2015) was the use of an exotic target, consisting of silicon with an extremely high concentration of boron. Low concentration of boron produced the transistor effects from the beginning and the very high concentration is in the focus of semiconductor research for degenerate hole concentration.…”

“…The estimation is based on excluding the α gyration for the hydrodynamics. Though the genuine many-fluid codes takes care of highly non-equilibrium plasma conditions (Fortov & Lakubov, 1998;Davidson, 2001), it may be preferred to base further steps on specific experiments of HB11 reactions following the preceding measurements Picciotto et al, 2014;Margarone et al, 2015).…”

Prompt gamma ray diagnostics and enhanced hadron-therapy using neutron-free nuclear reactions

“…[7][8][9] In the last decade a renewed interest on this topic has been shown through the possibility to trigger such nuclear reactions by using high power pulsed laser interacting with solid B-enriched targets. [10][11][12][13][14][15][16][17] Charged energetic particles are routinely used in medicine, in particular in cancer therapy. Currently hadron-therapy is becoming one of the most important medical procedures to treat solidified tumors instead of traditional radiotherapy treatments.…”