Journals >Matter and Radiation at Extremes
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2024
Volume: 9 Issue 1
10 Article(s)
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Research Articles
Relay, for a better MRE!
Ke Lan
Matter and Radiation at Extremes
- Publication Date: Jan. 01, 1900
- Vol. 9, Issue 1, 013001 (2024)
The acceleration of a high-charge electron bunch to 10 GeV in a 10-cm nanoparticle-assisted wakefield accelerator
Constantin Aniculaesei, Thanh Ha, Samuel Yoffe, Lance Labun, Stephen Milton, Edward McCary, Michael M. Spinks, Hernan J. Quevedo, Ou Z. Labun, Ritwik Sain, Andrea Hannasch, Rafal Zgadzaj, Isabella Pagano, Jose A. Franco-Altamirano, Martin L. Ringuette, Erhart Gaul, Scott V. Luedtke, Ganesh Tiwari, Bernhard Ersfeld, Enrico Brunetti, Hartmut Ruhl, Todd Ditmire, Sandra Bruce, Michael E. Donovan, Michael C. Downer, Dino A. Jaroszynski, and Bjorn Manuel Hegelich
An intense laser pulse focused onto a plasma can excite nonlinear plasma waves. Under appropriate conditions, electrons from the background plasma are trapped in the plasma wave and accelerated to ultra-relativistic velocities. This scheme is called a laser wakefield accelerator. In this work, we present results from aAn intense laser pulse focused onto a plasma can excite nonlinear plasma waves. Under appropriate conditions, electrons from the background plasma are trapped in the plasma wave and accelerated to ultra-relativistic velocities. This scheme is called a laser wakefield accelerator. In this work, we present results from a laser wakefield acceleration experiment using a petawatt-class laser to excite the wakefields as well as nanoparticles to assist the injection of electrons into the accelerating phase of the wakefields. We find that a 10-cm-long, nanoparticle-assisted laser wakefield accelerator can generate 340 pC, 10 ± 1.86 GeV electron bunches with a 3.4 GeV rms convolved energy spread and a 0.9 mrad rms divergence. It can also produce bunches with lower energies in the 4–6 GeV range..
Matter and Radiation at Extremes
- Publication Date: Jan. 01, 1900
- Vol. 9, Issue 1, 014001 (2024)
Semi-hydro-equivalent design and performance extrapolation between 100 kJ-scale and NIF-scale indirect drive implosion
Huasen Zhang, Dongguo Kang, Changshu Wu, Liang Hao, Hao Shen, Shiyang Zou, Shaoping Zhu, and Yongkun Ding
Extrapolation of implosion performance between different laser energy scales is investigated for indirect drive through a semi-hydro-equivalent design. Since radiation transport is non-hydro-equivalent, the peak radiation temperature of the hohlraum and the ablation velocity of the capsule ablator are not scale-invariaExtrapolation of implosion performance between different laser energy scales is investigated for indirect drive through a semi-hydro-equivalent design. Since radiation transport is non-hydro-equivalent, the peak radiation temperature of the hohlraum and the ablation velocity of the capsule ablator are not scale-invariant when the sizes of the hohlraum and the capsule are scale-varied. A semi-hydro-equivalent design method that keeps the implosion velocity Vi, adiabat αF, and
Matter and Radiation at Extremes
- Publication Date: Jan. 01, 1900
- Vol. 9, Issue 1, 015601 (2024)
Backward scattering of laser plasma interactions from hundreds-of-joules broadband laser on thick target
Peipei Wang, Honghai An, Zhiheng Fang, Jun Xiong, Zhiyong Xie, Chen Wang, Zhiyu He, Guo Jia, Ruirong Wang, Shu Zheng, Lan Xia, Wei Feng, Haitao Shi, Wei Wang, Jinren Sun, Yanqi Gao, and Sizu Fu
The use of broadband laser technology is a novel approach for inhibiting processes related to laser plasma interactions (LPIs). In this study, several preliminary experiments into broadband-laser-driven LPIs are carried out using a newly established hundreds-of-joules broadband second-harmonic-generation laser facilityThe use of broadband laser technology is a novel approach for inhibiting processes related to laser plasma interactions (LPIs). In this study, several preliminary experiments into broadband-laser-driven LPIs are carried out using a newly established hundreds-of-joules broadband second-harmonic-generation laser facility. Through direct comparison with LPI results for a traditional narrowband laser, the actual LPI-suppression effect of the broadband laser is shown. The broadband laser had a clear suppressive effect on both back-stimulated Raman scattering and back-stimulated Brillouin scattering at laser intensities below 1 × 1015 W cm-2. An abnormal hot-electron phenomenon is also investigated, using targets of different thicknesses..
Matter and Radiation at Extremes
- Publication Date: Jan. 01, 1900
- Vol. 9, Issue 1, 015602 (2024)
Resistive field generation in intense proton beam interaction with solid targets
W. Q. Wang, J. J. Honrubia, Y. Yin, X. H. Yang, and F. Q. Shao
The Brown–Preston–Singleton (BPS) stopping power model is added to our previously developed hybrid code to model ion beam–plasma interaction. Hybrid simulations show that both resistive field and ion scattering effects are important for proton beam transport in a solid target, in which they compete with each other. WheThe Brown–Preston–Singleton (BPS) stopping power model is added to our previously developed hybrid code to model ion beam–plasma interaction. Hybrid simulations show that both resistive field and ion scattering effects are important for proton beam transport in a solid target, in which they compete with each other. When the target is not completely ionized, the self-generated resistive field effect dominates over the ion scattering effect. However, when the target is completely ionized, this situation is reversed. Moreover, it is found that Ohmic heating is important for higher current densities and materials with high resistivity. The energy fraction deposited as Ohmic heating can be as high as 20%–30%. Typical ion divergences with half-angles of about 5°–10° will modify the proton energy deposition substantially and should be taken into account..
Matter and Radiation at Extremes
- Publication Date: Jan. 01, 1900
- Vol. 9, Issue 1, 015603 (2024)
Combining stochastic density functional theory with deep potential molecular dynamics to study warm dense matter
Tao Chen, Qianrui Liu, Yu Liu, Liang Sun, and Mohan Chen
In traditional finite-temperature Kohn–Sham density functional theory (KSDFT), the partial occupation of a large number of high-energy KS eigenstates restricts the use of first-principles molecular dynamics methods at extremely high temperatures. However, stochastic density functional theory (SDFT) can overcome this liIn traditional finite-temperature Kohn–Sham density functional theory (KSDFT), the partial occupation of a large number of high-energy KS eigenstates restricts the use of first-principles molecular dynamics methods at extremely high temperatures. However, stochastic density functional theory (SDFT) can overcome this limitation. Recently, SDFT and the related mixed stochastic–deterministic density functional theory, based on a plane-wave basis set, have been implemented in the first-principles electronic structure software ABACUS [Q. Liu and M. Chen, Phys. Rev. B 106 , 125132 (2022)]. In this study, we combine SDFT with the Born–Oppenheimer molecular dynamics method to investigate systems with temperatures ranging from a few tens of eV to 1000 eV. Importantly, we train machine-learning-based interatomic models using the SDFT data and employ these deep potential models to simulate large-scale systems with long trajectories. Subsequently, we compute and analyze the structural properties, dynamic properties, and transport coefficients of warm dense matter..
Matter and Radiation at Extremes
- Publication Date: Jan. 01, 1900
- Vol. 9, Issue 1, 015604 (2024)
Nonstationary laser-supported ionization wave in layer of porous substance with subcritical density
S. Yu Gus’kov, and R. A. Yakhin
A time-dependent analytical solution is found for the velocity of a plane ionization wave generated under nanosecond laser pulse action on the surface of a flat layer of low-Z porous substance with density less than the critical density of the produced plasma. With corrections for the two-dimensional nature of the probA time-dependent analytical solution is found for the velocity of a plane ionization wave generated under nanosecond laser pulse action on the surface of a flat layer of low-Z porous substance with density less than the critical density of the produced plasma. With corrections for the two-dimensional nature of the problem when a laser beam of finite radius interacts with a flat target, this solution is in quantitative agreement with measurements of ionization wave velocity in various experiments. The solution compared with experimental data covering wide ranges of performance conditions, namely, (3–8) × 1014 W cm-2 for laser pulse intensity, 0.3–3 ns for pulse duration, 0.35–0.53 μm for laser wavelength, 100–1000 μm for laser beam radius, 380–950 μm for layer thickness, 4.5–12 mg cm-3 for average density of porous substance, and 1–25 μm for average pore size. The parameters of the laser beam that ensure the generation of a plane ionization wave in a layer of subcritical porous matter are determined for the problem statements and are found to meet the requirements of practical applications..
Matter and Radiation at Extremes
- Publication Date: Jan. 01, 1900
- Vol. 9, Issue 1, 016601 (2024)
Ion emission from warm dense matter produced by irradiation with a soft x-ray free-electron laser
Josef Krása, Tomáš Burian, Věra Hájková, Jaromír Chalupský, Šimon Jelínek, Kateřina Frantálová, Michal Krupka, Zuzana Kuglerová, Sushil Kumar Singh, Vojtěch Vozda, Luděk Vyšín, Michal Šmíd, Pablo Perez-Martin, Marion Kühlman, Juan Pintor, Jakub Cikhardt, Matthias Dreimann, Dennis Eckermann, Felix Rosenthal, Sam M. Vinko, Alessandro Forte, Thomas Gawne, Thomas Campbell, Shenyuan Ren, YuanFeng Shi, Trevor Hutchinson, Oliver Humphries, Thomas Preston, Mikako Makita, Motoaki Nakatsutsumi, Xiayun Pan, Alexander Köhler, Marion Harmand, Sven Toleikis, Katerina Falk, and Libor Juha
We report on an experiment performed at the FLASH2 free-electron laser (FEL) aimed at producing warm dense matter via soft x-ray isochoric heating. In the experiment, we focus on study of the ions emitted during the soft x-ray ablation process using time-of-flight electron multipliers and a shifted Maxwell–Boltzmann veWe report on an experiment performed at the FLASH2 free-electron laser (FEL) aimed at producing warm dense matter via soft x-ray isochoric heating. In the experiment, we focus on study of the ions emitted during the soft x-ray ablation process using time-of-flight electron multipliers and a shifted Maxwell–Boltzmann velocity distribution model. We find that most emitted ions are thermal, but that some impurities chemisorbed on the target surface, such as protons, are accelerated by the electrostatic field created in the plasma by escaped electrons. The morphology of the complex crater structure indicates the presence of several ion groups with varying temperatures. We find that the ion sound velocity is controlled by the ion temperature and show how the ion yield depends on the FEL radiation attenuation length in different materials..
Matter and Radiation at Extremes
- Publication Date: Jan. 01, 1900
- Vol. 9, Issue 1, 016602 (2024)
Growth of ablative Rayleigh-Taylor instability induced by time-varying heat-flux perturbation
Yang Liu, De-Hua Zhang, Jing-Fei Xin, Yudong Pu, Jun Li, Tao Tao, Dejun Sun, Rui Yan, and Jian Zheng
The evolution of ablative Rayleigh–Taylor instability (ARTI) induced by single-mode stationary and time-varying perturbations in heat flux is studied numerically in two dimensions. Compared with the stationary case, time-varying heat-flux perturbation mitigates ARTI growth because of the enhanced thermal smoothing induThe evolution of ablative Rayleigh–Taylor instability (ARTI) induced by single-mode stationary and time-varying perturbations in heat flux is studied numerically in two dimensions. Compared with the stationary case, time-varying heat-flux perturbation mitigates ARTI growth because of the enhanced thermal smoothing induced by the wave-like traveling heat flux. A resonance is found to form when the phase velocity of the heat-flux perturbation matches the average sound speed in the ablation region. In the resonant regime, the coherent density and temperature fluctuations enhance the electron thermal conduction in the ablation region and lead to larger ablation pressure and effective acceleration, which consequently yield higher linear growth rate and saturated bubble velocity. The enhanced effective acceleration offers increased implosion velocity but can also compromise the integrity of inertial confinement fusion shells by causing faster ARTI growth..
Matter and Radiation at Extremes
- Publication Date: Jan. 01, 1900
- Vol. 9, Issue 1, 016603 (2024)
Design of high-temperature superconductors at moderate pressures by alloying AlH3 or GaH3
Xiaowei Liang, Xudong Wei, Eva Zurek, Aitor Bergara, Peifang Li, Guoying Gao, and Yongjun Tian
Since the discovery of hydride superconductors, a significant challenge has been to reduce the pressure required for their stabilization. In this context, we propose that alloying could be an effective strategy to achieve this. We focus on a series of alloyed hydrides with the AMH6 composition, which can be made via alSince the discovery of hydride superconductors, a significant challenge has been to reduce the pressure required for their stabilization. In this context, we propose that alloying could be an effective strategy to achieve this. We focus on a series of alloyed hydrides with the AMH6 composition, which can be made via alloying A15 AH3 (A = Al or Ga) with M (M = a group ⅢB or IVB metal), and study their behavior under pressure. Seven of them are predicted to maintain the A15-type structure, similar to AH3 under pressure, providing a platform for studying the effects of alloying on the stability and superconductivity of AH3. Among these, the A15-type phases of AlZrH6 and AlHfH6 are found to be thermodynamically stable in the pressure ranges of 40–150 and 30–181 GPa, respectively. Furthermore, they remain dynamically stable at even lower pressures, as low as 13 GPa for AlZrH6 and 6 GPa for AlHfH6. These pressures are significantly lower than that required for stabilizing A15 AlH3. Additionally, the introduction of Zr or Hf increases the electronic density of states at the Fermi level compared with AlH3. This enhancement leads to higher critical temperatures (Tc) of 75 and 76 K for AlZrH6 and AlHfH6 at 20 and 10 GPa, respectively. In the case of GaMH6 alloys, where M represents Sc, Ti, Zr, or Hf, these metals reinforce the stability of the A15-type structure and reduce the lowest thermodynamically stable pressure for GaH3 from 160 GPa to 116, 95, 80, and 85 GPa, respectively. Particularly noteworthy are the A15-type GaMH6 alloys, which remain dynamically stable at low pressures of 97, 28, 5, and 6 GPa, simultaneously exhibiting high Tc of 88, 39, 70, and 49 K at 100, 35, 10, and 10 GPa, respectively. Overall, these findings enrich the family of A15-type superconductors and provide insights for the future exploration of high-temperature hydride superconductors that can be stabilized at lower pressures..
Matter and Radiation at Extremes
- Publication Date: Jan. 01, 1900
- Vol. 9, Issue 1, 018401 (2024)
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