scholarly journals Collective stopping power in laser driven fusion plasmas for block ignition

2009 ◽  
Vol 28 (1) ◽  
pp. 3-9 ◽  
Author(s):  
B. Malekynia ◽  
H. Hora ◽  
N. Azizi ◽  
M. Kouhi ◽  
M. Ghoranneviss ◽  
...  
Keyword(s):  
Contrast Ratio ◽  
Picosecond Laser ◽  
Laser Pulses ◽  
Alpha Particles ◽  
Stopping Power ◽  
Necessary Condition ◽  
Laser Fusion ◽  
Fusion Plasmas ◽  
Alternative Scheme ◽  
Fusion Scheme

AbstractIn contrast to the usual laser fusion scheme with spherical irradiation and very high compression and ignition of fuel, the alternative scheme with side-on ignition of uncompressed solid density of fuel (Chu) may lead to a solution by using the now available picosecond laser pulses with higher than petawatt power. A necessary condition is to use clean laser pulses with better than 108contrast ratio for suppression of relativistic self-focusing. When updating the analysis of Chu for fusion of deuterium-tritium and proton-11B, one problem is that the correct use of the stopping power of the alpha particles had to be solved. Discrepancies are evaluated in view of the stopping power at the low temperature range of the plasmas where the change of the emitted bremsstrahlung is involved.

scholarly journals Laser fusion with nonlinear force driven plasma blocks: Thresholds and dielectric effects

2009 ◽  
Vol 27 (2) ◽  
pp. 207-222 ◽  
Author(s):  
H. Hora
Keyword(s):  
Contrast Ratio ◽  
Picosecond Laser ◽  
Laser Pulses ◽  
State Density ◽  
Alpha Particles ◽  
Collective Effects ◽  
Laser Fusion ◽  
Nonlinear Force ◽  
Current Densities ◽  
Energy Flux Density

AbstractAnomalous interaction of picosecond laser pulses of terawatt to petawatt power is due to suppression of relativistic self-focusing if prepulses are cut-off by a contrast ratio higher than 108, resulting in quasi-neutral directed plasma blocks with deuterium tritium ion current densities above 1011A/cm2. This is still not high enough for ignition of solid-state density deuterium tritium because the energy flux densityE* has to be higher than the threshold of 4 ×108J/cm2obtained within the theory of Chu (1972). A revision of this evaluation shows a reduction of this threshold by a factor 20 if the later discovered inhibition factors for thermal conduction because of double layer effects as well as the shorter stopping lengths of the alpha particles due to collective effects are taken into account. Under these relaxed conditions, the parameters of nonlinear force generated blocks of dielectrically increased thickness for deuterium tritium ignition with directed ions of energies near the 80 keV resonances are discussed.

scholarly journals Laser fusion energy from p-7Li with minimized radioactivity

2012 ◽  
Vol 30 (3) ◽  
pp. 459-463 ◽  
Author(s):  
M. Ghoranneviss ◽  
A. Salar Elahi ◽  
H. Hora ◽  
G.H. Miley ◽  
B. Malekynia ◽  
...  
Keyword(s):  
Cross Sections ◽  
Fusion Energy ◽  
Contrast Ratio ◽  
Picosecond Laser ◽  
Laser Pulses ◽  
Laser Ignition ◽  
Laser Fusion ◽  
High Contrast ◽  
Solid Deuterium ◽  
Very High

AbstractThe new possibility of side-on laser ignition of p-11B with negligible radioactivity encouraged to study the fusion of solid state p-7Li fuel that again turns out to be only about 10 times more difficult than the side-on ignition of solid deuterium-tritium using petawatt-picosecond laser pulses at anomalous interaction conditions if very high contrast ratio. Updated cross sections of the nuclear reaction are included.

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

2009 ◽  
Vol 27 (2) ◽  
pp. 233-241 ◽  
Author(s):  
B. Malekynia ◽  
M. Ghoranneviss ◽  
H. Hora ◽  
G.H. Miley
Keyword(s):  
Threshold Value ◽  
Laser Pulses ◽  
High Energy ◽  
Skin Layer ◽  
Alpha Particles ◽  
Hydrodynamic Theory ◽  
Laser Fusion ◽  
Collision Theory ◽  
Collective Effect ◽  
Very High Energy

AbstractThe anomaly at laser plasma interaction at laser pulses of TW to PW power and ps duration led to a very unique generation of quasi-neutral plasma blocks by a skin layer interaction avoiding the relativistic self-focusing. This is in contrast to numerous usual experiments. The plasma blocks have ion current densities above 1011A/cm2and may be used for a fast ignition scheme with comparably low compression of the deuterium tritium (DT) fuel. The difficulty is that a very high energy flux densityE* of the ions is necessary according to the hydrodynamic theory (Bobin, 1971, 1974; Chu, 1972). This theory did not include the later discovered collective effect for the stopping power of the alpha particles. One problem is being discussed, whether the Bethe-Bloch binary collision theory or the collective collision theory of Gabor has to be applied. The inclusion of the collective effect results in a reduction of the threshold value ofE* for ignition by a factor of about fife.

scholarly journals Nonlinear force driven plasma blocks igniting solid density hydrogen boron: Laser fusion energy without radioactivity

2009 ◽  
Vol 27 (3) ◽  
pp. 491-496 ◽  
Author(s):  
H. Hora ◽  
G.H. Miley ◽  
N. Azizi ◽  
B. Malekynia ◽  
M. Ghoranneviss ◽  
...  
Keyword(s):  
Energy Production ◽  
Radiation Effects ◽  
Fusion Energy ◽  
Laser Pulses ◽  
High Energy ◽  
Nuclear Radiation ◽  
Laser Fusion ◽  
Surprising Result ◽  
Neutron Generation ◽  
Alternative Scheme

AbstractEnergy production by laser driven fusion energy is highly matured by spherical compression and ignition of deuterium-tritium (DT) fuel. An alternative scheme is the fast ignition where petawatt (PW)-picosecond (ps) laser pulses are used. A significant anomaly was measured and theoretically analyzed with very clean PW-ps laser pulses for avoiding relativistic self focusing. This permits a come-back of the side-on ignition scheme of uncompressed solid DT, which is in essential contrast to the spherical compression scheme. The conditions of side-on ignition thresholds needed exorbitantly high energy flux densities E*. These conditions are now in reach by using PW-ps laser pulses to verify side-on ignition for DT. Generalizing this to side-on igniting solid state density proton-Boron-11 (HB11) arrives at the surprising result that this is one order of magnitude more difficult than the DT fusion. This is in contrast to the well known impossibility of igniting HB11 by spherical laser compression and may offer fusion energy production with exclusion of neutron generation and nuclear radiation effects with a minimum of heat pollution in power stations and application for long mission space propulsion.

Computations for nonlinear force driven plasma blocks by picosecond laser pulses for fusion

2005 ◽  
Vol 71 (1) ◽  
pp. 35-51 ◽  
Author(s):  
Y. CANG ◽  
F. OSMAN ◽  
H. HORA ◽  
J. ZHANG ◽  
J. BADZIAK ◽  
...  
Keyword(s):  
Picosecond Laser ◽  
Laser Pulses ◽  
High Gain ◽  
Skin Depth ◽  
Laser Fusion ◽  
Fusion Reactions ◽  
Picosecond Laser Pulses ◽  
Nonlinear Force ◽  
Ion Emission ◽  
Hydrodynamic Code

The concept of the fast ignitor for laser fusion has led to some modifications in applying petawatt-picosecond (PW-ps) laser-produced high intensity particle beams to ignite deuterium-tritium (DT) fuel. Some very anomalous measurements of ion emission from targets irradiated by picosecond laser pulses led to the development of a skin depth interaction scheme where a defined control of prepulses is necessary. Based on these experimental facts, we have applied a one-dimensional two-fluid hydrodynamic code to understand how the nonlinear ponderomotive force generates two plasma blocks, one moving against the laser light (ablation) and the other moving into the target. This compressed block produces an ion current density of above 10$^{11}$ A cm$^{-2}$ and an ion energy of about 100 keV. This may be a rather promising option to use PW-ps laser pulses for igniting fusion in solid density DT fuel, realizing very high gain controlled fusion reactions.

Methods for the shaping high-power picosecond laser pulses with a high-contrast ratio

1998 ◽  
Author(s):  
V. A. Malinov ◽  
A. V. Charukchev ◽  
V. N. Chernov ◽  
N. V. Nikitin ◽  
S. L. Potapov ◽  
...  
Keyword(s):  
High Power ◽  
Contrast Ratio ◽  
Picosecond Laser ◽  
Laser Pulses ◽  
High Contrast ◽  
Picosecond Laser Pulses

scholarly journals Application of picosecond terawatt laser pulses for fast ignition of fusion

2013 ◽  
Vol 31 (2) ◽  
pp. 249-256 ◽  
Author(s):  
H. Hora ◽  
G.H. Miley ◽  
M. Ghoranneviss ◽  
A. Salar Elahi
Keyword(s):  
Laser Energy ◽  
Basic Result ◽  
Contrast Ratio ◽  
Picosecond Laser ◽  
Laser Pulses ◽  
Fast Ignition ◽  
Plasma Properties ◽  
Ponderomotive Forces ◽  
Nonlinear Force ◽  
Terawatt Laser

AbstractIn this research, we presented the application of picosecond terawatt laser pulses for ultrahigh acceleration of plasma blocks for fast ignition of fusion. Ultrahigh acceleration of plasma blocks after irradiation of picosecond laser pulses of around terawatt power in the range of 1020 cm/s2was discovered by Sauerbrey (1996) as measured by Doppler effect where the laser intensity was up to about 1018W/cm2. This is several orders of magnitude higher than acceleration by irradiation based on thermal interaction of lasers has produced. This ultrahigh acceleration resulted from hydrodynamic computations at plane target interaction in 1978 at comparable conditions where the interaction was dominated by the nonlinear (generalized ponderomotive) forces where the laser energy was instantly converted into plasma motion in contrast to slow and delayed thermal collision processes. After clarifying this basic result, the application of the plasma blocks for side-on ignition of solid density or modestly compressed fusion fuel following the theory of Chu (1971) is updated in view of later discovered plasma properties and the ignition of deuterium tritium and of proton-11B appeared possible for a dozen of PW-PS laser pulses if an extremely high contrast ratio avoided relativistic self-focusing. A re-evaluation of more recent experiment confirms the acceleration by the nonlinear force, and the generation of the fusion flame with properties of Rankine-Hugoniot shocks is reported.

Electric field probing by picosecond laser pulses

1992 ◽  
Vol 28 (12) ◽  
pp. 1137 ◽  
Author(s):  
A. Krotkus ◽  
V. Pašiškevičius
Keyword(s):  
Electric Field ◽  
Picosecond Laser ◽  
Laser Pulses ◽  
Picosecond Laser Pulses

Alternative Laser Driven Fusion Reactions for Nuclear Energy Without Radioactivity

2010 ◽  
Author(s):  
Mahmoud Ghoranneviss ◽  
Babak Malekynia ◽  
Nader Azizi ◽  
Henrich Hora ◽  
George H. Miley
Keyword(s):  
Nuclear Energy ◽  
Ponderomotive Force ◽  
Fusion Energy ◽  
Contrast Ratio ◽  
Laser Pulses ◽  
State Density ◽  
Helium Isotope ◽  
Fusion Reactions ◽  
Solid Density ◽  
Radioactive Radiation

Following the first result of generating nuclear fusion energy without dangerous radioactive radiation by laser ignition of the proton-11Boron reaction (HB11), we applied this method to evaluate other fusion reactions with no primary neutron production as the proton-7Lithium reaction (HLi7) and of the burning of solid density helium isotope 3He (He3-He3). The new method is a combination of now available laser pulses of 10 petawatt (PW) power and duration in the range of picoseconds (ps) or less. The new mechanism follows the initial theory of Chu and of Bobin for side-on ignition of solid state density fusion fuel developed in about 1972 where some later known physics phenomena had to be added. The essential innovation is the use of the discovery of a predicted anomaly when the mentioned laser pulses are sufficiently clean, i.e. free from prepulses by at least a contrast ratio 108 where acceleration by the nonlinear (ponderomotive) force is dominating.

scholarly journals Sputtering of Neutral Molecules and Molecular Ions From the Adenine Crystal Surface Induced by the UV Picosecond Laser Pulse

1982 ◽  
Vol 1 (1) ◽  
pp. 37-43 ◽  
Author(s):  
V. S. Antonov ◽  
V. S. Letokhov ◽  
Yu. A. Matveyets ◽  
A. N. Shibanov
Keyword(s):  
Laser Radiation ◽  
Kinetic Energy ◽  
Crystal Surface ◽  
Picosecond Laser ◽  
Laser Pulses ◽  
Molecular Ions ◽  
Laser Radiation Intensity ◽  
Ion Sputtering ◽  
Absorbed Energy ◽  
Picosecond Laser Pulse

This paper presents the results of observation of sputtering of neutral molecules and ions from the crystal adenine surface induced by fourth-harmonic Nd:YAG laser radiation with a pulse duration of 30 ps. The energy fluence of laser pulses was in the region (1–3) × 10−4 J/cm2. The kinetic energy distribution of the sputtered molecules spreads up to 0.7 eV. The experiment shows that the threshold of adenine molecular ion sputtering is connected with absorbed energy density in upper layers of the crystal surface but not by laser radiation intensity.

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