Inertial electrostatic confinement and nuclear fusion in the interelectrode plasma of a nanosecond vacuum discharge. II: Particle-in-cell simulations

Warm Dense Matter Generation and DD Synthesis at Vacuum Discharge with Deuterium‐Loaded Pd Anode

“…During this time the electron beam extracted from cathode is reaching the deuterium-loaded anode and starting to interact with the Pd surface. This relatively fast initial stage of discharge in our experiment is understood still poorly, in comparison with more late processes of virtual cathode and potential well formation [10,29]. At this section we would like at first to pay attention and to discuss some specifics of possible particle emission at initial stage of discharge, registered at experiment earlier [9], as well as to consider some features of Pd anode surface morphology.…”

“…In fact, the pulsating neutron yield is appearing in experiment just as d eff is decreasing. PIC modeling of this ( fig.9) particular experimental regime ( fig.12a, compare with geometry presented on fig.4) gives ion trajectories (fig.12b) and energies (not shown here, see [29]) which are corresponding namely to their periodic oscillations (ions acceleration -deceleration) at PW. In summary, neutron yield as a single peak is the result of a single collapse of ions at the well bottom at neutralization of VC in regime T v ≈ T pulse , (figs.2,3) and pulsating (oscillatory) yield corresponds to ions harmonic oscillations at PW (T v << T pulse , figs.9,11) accompanied by periodic collapses at the axis (PW bottom).…”

“…On the basis of this model the explanations were given for the early experimental data of A.A. Plutto [28] on occasional anomalous ions acceleration. Our results of PIC simulations for real electrodes geometry and vacuum discharge conditions of experiment [8,9] using electrodynamic code KARAT [10,29] have recognizing that the concept of PW is more universal and represents the basis for IEC fusion reactor: namely, a quasistationary PW at interelectrode space with depth up to ∼ 80% of the applied voltage provides radial electrostatic acceleration of ions up to the same energies. Correspondingly, head-on collisions of ions at the axis with energies of a few tens of keV is followed by DD nuclear synthesis, transforming the interelectrode space into a reactor chamber.…”

“…Further, since the experimental current I A exceeds the limiting Langmuir value I A > I L [25], cumulative convergence of head-on e-beams at the axis (inside the space restricted by Pd tubes) provides total deceleration of electrons (as well as partial reflection of electrons outside, V r /c >0), and VC appears (at r ≈ 0.1 cm). Due to VC, a negative potential about a few tens of kV will appear at the axis (at Z ≈ 1.4-1.6 cm), and the internal part of the near anode area will be filled by accelerated ions (fig.5, red horizontal line V r /c ≈ 0 at r = 0 -0.3 cm interval; this line will be split, in the ion scale of velocities, at r = 0 (on the Z axis) into two head-on converged branches of ions [29] with velocities V i r /c = ± 0.5×10 −2 ). The well depth oscillates around of the applied voltage with amplitude up to 20%.…”

“…(Online colour: www.cpp-journal.org). The complex physics of nanosecond discharge processes and the mechanisms of microfusion were poorly understood at first [8], and motivated the interest in complementary PIC (particlein-cell) KARAT simulations [10,24,29]. In addition to representing the key points of general physical picture, computer modelling allows clarification of the details of the experimental data.…”