Babak Khanbabaei

With the advent of proton fast driven ignition and more efficient energy transport of the ignitor beam, we might be interested to try successful ignition of the targets mixed with advanced fuels where DT main fuel acts simply as a seed. Here, we have examined the ignition and burn conditions of a DT–3He pre-compressed fuel pellet driven by proton ignitor beam generated separately by the well-known laser-accelerated ion mechanism. We have, first, derived the zero-dimensional model of the energy balance equations of one fluid, three temperatures (i.e. electron, ion and radiation temperatures) including the most important gain and loss processes. Then, in order to evaluate the feasibility of the system and its energy gain, these coupled equations are solved numerically. It has been shown that the system energy gain quickly responses and is sensitive to the initial concentration of He-3, proton beam power and total areal density of fuel. A saturation in energy gain for ρR > 8 g/cm2 has been demonstrated which is equivalent to burn fraction of higher than 0.4. Enhancement in energy gain exceeds 33 percent. Moreover, in a complete catalytic regime of both tritium and He-3 ions, as much as an order of magnitude reduction in neutron flux is observed. © 2018 Elsevier B.V.

Conditions for self-sustained burning of deuterium-helium3 as an advanced fuel in a degenerate regime have been investigated by the four temperature theory. The four temperature theory can describe the radiation field more accurately than the three temperature model. According to the four temperature theory, the photon distribution undergoes a transition from an optically thick to optically thin regime at a certain cut-off energy. The main goal of this research is to determine the critical burn-up parameter for deuterium-helium3 fuel in the degenerate regime in which the ion-electron energy exchange and the bremsstrahlung loss are smaller than those of the classic plasma. To prevent high tritium breeding via deuterium-deuterium and deuterium-tritium reactions, the utilization of equimolar deuterium-helium3 fuel is avoided. © 2017 Author(s).

In this paper, we have improved the fast ignition scheme in order to have more authority needed for high-energy-gain. Due to the more penetrability and energy deposition of the particle beams in fusion targets, we employ a laser-to-ion converter foil as a scheme for generating energetic ion beams to ignite the fusion fuel. We find the favorable intensity and wavelength of incident laser by evaluating the laser-proton conversion gain. By calculating the source-target distance, proton beam power and energy are estimated. Our analysis is generalized to the plasma degeneracy effects which can increase the fusion gain several orders of magnitude by decreasing the ion-electron collisions in the plasma. It is found that the wavelength of 0.53 μm and the intensity of about 1020 W/cm2, by saving about 10% conversion coefficient, are the suitable measured values for converting a laser into protons. Besides, stopping power and fusion burn calculations have been done in degenerate and non-degenerate plasma mediums. The results indicate that in the presence of degeneracy, the rate of fusion enhances. © 2016 Chinese Physical Society and IOP Publishing Ltd.

The fast ignition scheme is recognized as a potentially promising approach to achieve the high-energy-gain target performance needed for commercial inertial confinement fusion. The hot spot heating process by an assumed deuteron beam is evaluated in order to estimate the contribution of the energy produced by the deuteron beam-target fusion to the heating process. So, deuteron beam was considered with Maxwellian energy distribution at temperature of 3MeV. Then, the deuteron energy loss and range, Includes Coulomb and nuclear elastic interactions, in the uniformly pre-compressed fuel, with density 300gcm-3, were calculated. By calculating the contribution of alpha particles produced by the athermal nuclear reactions and nuclear elastic scattering, power deposition of deuteron beams increased up 6% compared with the fast ignition by similar ion beams. This can lead to reduced energy delivered by the external beam.

One of the main concerns about the currentworking on nuclear power reactors is the potential hazard of their radioactive waste. There is hope that this issue will be reduced in next generation nuclear fusion power reactors. Reactors will release nuclear energy through microexplosions that occur in a mixture of hydrogen isotopes of deuterium and tritium. However, there exist radiological hazards due to the accumulation of tritium in the blanket layer. A catalytic fusion reaction of DTx mixture may stand between DD and an equimolar DT approach in which the fusion process continues with a small amount of tritium seed. In this paper, we investigate the possibility of DTx reaction in the fast ignition (FI) scheme. The kinematic study of the main mechanism of the energy gain-loss term, which may disturb the ignition and burn process, was performed in FI and the optimum values of precompressed fuel and proton beam driver were derived. The recommended values of fuel parameters are: areal density ρR ≥ 5g·cm-2 and initial tritium fraction x ≤ 0. 025. For the proton beam, the corresponding optimum interval values are proton average energy 3 ≤ Ep ≤ 10 MeV, pulse duration 5 ≤ tp ≤ 15 ps and power 5 ≤ Wp ≤ 12 × 1022 (keV·cm3·ps-1). It was proved that under the above conditions, a fast ignition DTx reaction stays in the catalytic regime. © Indian Academy of Sciences.