Erratum: Stopping power of dense plasmas: The collisional method and limitations of the dielectric formalism [Phys. Rev. E 97, 023202 (2018)].

This corrects the article DOI: 10.1103/PhysRevE.97.023202.

Stopping power of dense plasmas: The collisional method and limitations of the dielectric formalism.

We present a study of the stopping power of plasmas using two main approaches: the collisional (scattering theory) and the dielectric formalisms. In the former case, we use a semiclassical method based on quantum scattering theory. In the latter case, we use the full description given by the extension of the Lindhard dielectric function for plasmas of all degeneracies. We compare these two theories and show that the dielectric formalism has limitations when it is used for slow heavy ions or atoms in dense plasmas. We present a study of these limitations and show the regimes where the dielectric formalism can be used, with appropriate corrections to include the usual quantum and classical limits. On the other hand, the semiclassical method shows the correct behavior for all plasma conditions and projectile velocity and charge. We consider different models for the ion charge distributions, including bare and dressed ions as well as neutral atoms.

Bulk-Fill Composites: Effectiveness of Cure With Poly- and Monowave Curing Lights and Modes.

This study compared the effectiveness of cure of bulk-fill composites using polywave light-emitting diode (LED; with various curing modes), monowave LED, and conventional halogen curing lights. The bulk-fill composites evaluated were Tetric N-Ceram bulk-fill (TNC), which contained a novel germanium photoinitiator (Ivocerin), and Smart Dentin Replacement (SDR). The composites were placed into black polyvinyl molds with cylindrical recesses of 4-mm height and 3-mm diameter and photopolymerized as follows: Bluephase N Polywave High (NH), 1200 mW/cm2 (10 seconds); Bluephase N Polywave Low (NL), 650 mW/cm2 (18.5 seconds); Bluephase N Polywave soft-start (NS), 0-650 mW/cm2 (5 seconds) → 1200 mW/cm2 (10 seconds); Bluephase N Monowave (NM), 800 mW/cm2 (15 seconds); QHL75 (QH), 550 mW/cm2 (21.8 seconds). Total energy output was fixed at 12,000 mJ/cm2 for all lights/modes, with the exception of NS. The cured specimens were stored in a light-proof container at 37°C for 24 hours, and hardness (Knoop Hardness Number) of the top and bottom surfaces of the specimens was determined using a Knoop microhardness tester (n=6). Hardness data and bottom-to-top hardness ratios were subjected to statistical analysis using one-way analysis of variance/Scheffe's post hoc test at a significance level of 0.05. Hardness ratios ranged from 38.43% ± 5.19% to 49.25% ± 6.38% for TNC and 50.67% ± 1.54% to 67.62% ± 6.96% for SDR. For both bulk-fill composites, the highest hardness ratios were obtained with NM and lowest hardness ratios with NL. While no significant difference in hardness ratios was observed between curing lights/modes for TNC, the hardness ratio obtained with NM was significantly higher than the hardness ratio obtained for NL for SDR.

Energy loss and Z oscillations of atomic beams in plasmas.

We apply a semiclassical partial-wave-scattering method based on the Wentzel-Kramers-Brillouin approximation to study the transport cross section and the energy loss of neutral or ionized atomic beams in plasmas. This approach reproduces the exact quantum result in a satisfactory manner, even in several extreme conditions of plasma densities and temperatures, and agrees with the results of linear or perturbative calculations for bare ions in the appropriate limits. We pay special attention to low projectile speeds where strong oscillations in the transport cross section and energy loss-as a function of projectile's atomic number-are observed. We study these oscillatory phenomena varying the projectile speed and its ionization degree and the plasma temperature and density. We analyze in physical terms these effects and present a diagram of plasma conditions showing the regions where these oscillations may occur for both neutral and ionized beams.

The screening and stopping coefficients of slow light ions.

We present a theoretical approach to study the screening charge density n(s)(r) and the respective stopping coefficient Q for hydrogen and helium at the low velocity limit. An electron gas, with electronic density n(e), is used to represent the conduction or valence electrons of the target material. Solving numerically the Schrödinger radial equation, for a given potential V (r), the phase shifts δ(l) and the corresponding stopping coefficient Q are calculated as a function of n(e). The cusp condition and the Friedel sum rule are imposed on the charge density n(r) = n(s)(r)+n(e) at the origin and to the phase shifts, respectively. The results are compared with density functional calculations and with available experimental results.