High‐voltage electric pulse rock breaking has excellent potential for exploiting deep geothermal resources. Numerous researchers have conducted experimental studies on this topic, particularly in rock mechanics, where the breakdown occurs. However, there has been limited scholarly research on drilling fluid. Therefore, the study focuses on the drilling fluid suitable for electric pulse drilling, considering the characteristics of electric pulse rock breaking, which differ from traditional rock breaking. The study focused on the impact of various drilling fluid parameters on the effectiveness of electric impulse rock breaking using red sandstone as the experimental material. This was investigated using the finite element method, and indoor electric rock‐breaking tests were conducted in a drilling fluid environment. The results indicate that the plasma channel mainly grows in the permeable layer of the drilling fluid, resulting in shallow rock breaking depth in the drilling fluid environment. The pore permeated by drilling fluid guides the growth of the plasma channel. The higher the conductivity of the drilling fluid, the closer the ion channel of rock breaking by electric pulse is to the rock surface. This results in a smaller crushing volume and shallower damage depth, which is more detrimental to rock breaking by an electric pulse. The viscosity of drilling fluid can impede the breakdown to some extent. In this paper, the influence of drilling fluid parameters on electro‐pulse rock‐breaking technology is preliminarily studied, which has significant reference value for the selection of actual drilling fluid.
{"title":"Growth mechanism of high‐voltage electric pulse rock breaking 3D plasma channel in drilling fluid environment","authors":"Xiaohua Zhu, Siqi Liu, Weiji Liu, Xin Zhou, Wuji Tang","doi":"10.1002/ctpp.202400035","DOIUrl":"https://doi.org/10.1002/ctpp.202400035","url":null,"abstract":"High‐voltage electric pulse rock breaking has excellent potential for exploiting deep geothermal resources. Numerous researchers have conducted experimental studies on this topic, particularly in rock mechanics, where the breakdown occurs. However, there has been limited scholarly research on drilling fluid. Therefore, the study focuses on the drilling fluid suitable for electric pulse drilling, considering the characteristics of electric pulse rock breaking, which differ from traditional rock breaking. The study focused on the impact of various drilling fluid parameters on the effectiveness of electric impulse rock breaking using red sandstone as the experimental material. This was investigated using the finite element method, and indoor electric rock‐breaking tests were conducted in a drilling fluid environment. The results indicate that the plasma channel mainly grows in the permeable layer of the drilling fluid, resulting in shallow rock breaking depth in the drilling fluid environment. The pore permeated by drilling fluid guides the growth of the plasma channel. The higher the conductivity of the drilling fluid, the closer the ion channel of rock breaking by electric pulse is to the rock surface. This results in a smaller crushing volume and shallower damage depth, which is more detrimental to rock breaking by an electric pulse. The viscosity of drilling fluid can impede the breakdown to some extent. In this paper, the influence of drilling fluid parameters on electro‐pulse rock‐breaking technology is preliminarily studied, which has significant reference value for the selection of actual drilling fluid.","PeriodicalId":10700,"journal":{"name":"Contributions to Plasma Physics","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141511199","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Correlated classical and quantum many-particle systems out of equilibrium are of high interest in many fields, including dense plasmas, correlated solids, and ultracold atoms. Accurate theoretical description of these systems is challenging both, conceptionally and with respect to computational resources. While for classical systems, in principle, exact simulations are possible via molecular dynamics, this is not the case for quantum systems. Alternatively, one can use many-particle approaches such as hydrodynamics, kinetic theory, or nonequilibrium Green functions (NEGF). However, NEGF exhibit a very unfavorable cubic scaling of the CPU time with the number of time steps. An alternative is the G1–G2 scheme [N. Schlünzen et al., Phys. Rev. Lett. 124, 076601 (2020)] which allows for NEGF simulations with time linear scaling, however, at the cost of large memory consumption. The reason is the need to store the two-particle correlation function. This problem can be overcome for a number of approximations by reformulating the kinetic equations in terms of fluctuations – an approach that was developed, for classical systems, by Yu.L. Klimontovich [JETP 33, 982 (1957)]. Here, we present an overview of his ideas and extend them to quantum systems. In particular, we demonstrate that this quantum fluctuations approach can reproduce the nonequilibrium GW approximation [E. Schroedter et al., Cond. Matt. Phys. 25, 23401 (2022)] promising high accuracy at low computational cost which arises from an effective semiclassical stochastic sampling procedure. We also demonstrate how to extend the approach to the two-time exchange-correlation functions and the density response properties. [E. Schroedter et al., Phys. Rev. B 108, 205109 (2023)]. The results are equivalent to the Bethe–Salpeter equation for the two-time exchange-correlation function when the generalized Kadanoff-Baym ansatz with Hartree-Fock propagators is applied [E. Schroedter and M. Bonitz, phys. stat. sol. (b) 2024, 2300564].
{"title":"Classical and quantum theory of fluctuations for many-particle systems out of equilibrium","authors":"E. Schroedter, M. Bonitz","doi":"10.1002/ctpp.202400015","DOIUrl":"https://doi.org/10.1002/ctpp.202400015","url":null,"abstract":"<p>Correlated classical and quantum many-particle systems out of equilibrium are of high interest in many fields, including dense plasmas, correlated solids, and ultracold atoms. Accurate theoretical description of these systems is challenging both, conceptionally and with respect to computational resources. While for classical systems, in principle, exact simulations are possible via molecular dynamics, this is not the case for quantum systems. Alternatively, one can use many-particle approaches such as hydrodynamics, kinetic theory, or nonequilibrium Green functions (NEGF). However, NEGF exhibit a very unfavorable cubic scaling of the CPU time with the number of time steps. An alternative is the G1–G2 scheme [N. Schlünzen et al., Phys. Rev. Lett. <b>124</b>, 076601 (2020)] which allows for NEGF simulations with time linear scaling, however, at the cost of large memory consumption. The reason is the need to store the two-particle correlation function. This problem can be overcome for a number of approximations by reformulating the kinetic equations in terms of fluctuations – an approach that was developed, for classical systems, by Yu.L. Klimontovich [JETP <b>33</b>, 982 (1957)]. Here, we present an overview of his ideas and extend them to quantum systems. In particular, we demonstrate that this quantum fluctuations approach can reproduce the nonequilibrium <i>GW</i> approximation [E. Schroedter <i>et al</i>., Cond. Matt. Phys. <b>25</b>, 23401 (2022)] promising high accuracy at low computational cost which arises from an effective semiclassical stochastic sampling procedure. We also demonstrate how to extend the approach to the two-time exchange-correlation functions and the density response properties. [E. Schroedter <i>et al</i>., Phys. Rev. B <b>108</b>, 205109 (2023)]. The results are equivalent to the Bethe–Salpeter equation for the two-time exchange-correlation function when the generalized Kadanoff-Baym ansatz with Hartree-Fock propagators is applied [E. Schroedter and M. Bonitz, phys. stat. sol. (b) 2024, 2300564].</p>","PeriodicalId":10700,"journal":{"name":"Contributions to Plasma Physics","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ctpp.202400015","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141488582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Forced propagation of perturbations in a magnetosonic wave are considered. The driving force may be caused by stimulated Mandelstam–Brillouin scattering of optic waves or by intense magnetosonic exciter. Some heating‐cooling function which takes into account radiative cooling and unspecified heating is taken into consideration, as well as nonlinearity of a medium. Both these factors make the excitation particular. The analytical and numerical evaluations reveal that forced oscillations differ essentially from the free propagation and depend on a number of dimensionless parameters such as the ratio of speed of exciter to the eigen speed of excited wave, the ratio of speed of an excited wave to its eigen speed, and the dimensionless magnitude of an exciter. Forced excitation is resonant if speed of an exciter coincides with the eigen speed of excited wave but may give rise to the excited perturbations with the speed different from the eigen one. The preliminary evaluations may be helpful for the controlled excitation of perturbations in natural and laboratory plasma systems and indication of the parameters of an exciter.
{"title":"Resonant and nonresonant excitation of waves in a planar magnetosonic flow","authors":"A. Perelomova","doi":"10.1002/ctpp.202400033","DOIUrl":"https://doi.org/10.1002/ctpp.202400033","url":null,"abstract":"Forced propagation of perturbations in a magnetosonic wave are considered. The driving force may be caused by stimulated Mandelstam–Brillouin scattering of optic waves or by intense magnetosonic exciter. Some heating‐cooling function which takes into account radiative cooling and unspecified heating is taken into consideration, as well as nonlinearity of a medium. Both these factors make the excitation particular. The analytical and numerical evaluations reveal that forced oscillations differ essentially from the free propagation and depend on a number of dimensionless parameters such as the ratio of speed of exciter to the eigen speed of excited wave, the ratio of speed of an excited wave to its eigen speed, and the dimensionless magnitude of an exciter. Forced excitation is resonant if speed of an exciter coincides with the eigen speed of excited wave but may give rise to the excited perturbations with the speed different from the eigen one. The preliminary evaluations may be helpful for the controlled excitation of perturbations in natural and laboratory plasma systems and indication of the parameters of an exciter.","PeriodicalId":10700,"journal":{"name":"Contributions to Plasma Physics","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141367280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Marlene Rosenberg, James Dufty, Peter Hartmann, Zoltán Donkó
{"title":"Strongly coupled Coulomb systems: Honoring Ken Golden and Gabor Kalman","authors":"Marlene Rosenberg, James Dufty, Peter Hartmann, Zoltán Donkó","doi":"10.1002/ctpp.202400068","DOIUrl":"10.1002/ctpp.202400068","url":null,"abstract":"","PeriodicalId":10700,"journal":{"name":"Contributions to Plasma Physics","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141367637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We consider the excitation of terahertz (THz) electromagnetic fields by interaction of radially polarized laser pulses of diverse profiles with a homogenous plasma density slab. We utilize the properties of the laser pulse to generate THz fields in a plasma slab. It is shown that the radial ponderomotive force exerted by laser imparts an oscillatory velocity to plasma electrons and drives a nonlinear current in azimuthal direction exciting THz electromagnetic fields in the plasma slab. The dependence of the excited radial electric field and azimuthal magnetic field on axial and radial parameters of the plasmas lab, as well as on the slab thickness and laser pulse width size, is investigated. It is demonstrated that the terahertz fields are generated most efficiently with a frequency close to the plasma frequency. It is also shown that the intensity of the excited fields may be optimized and controlled by the plasma slab and laser pulse parameters. Rectangular‐triangular, super‐Gaussian, and sinusoidal lasers exhibit a significantly steeper radial gradient of ponderomotive potential in comparison with other laser profiles, and excite intense radial electric fields and generate azimuthal magnetic fields in plasma slab. The numerical results closely follow the scaling laws and match with previous experimental and simulation results.
{"title":"Radially polarized femtosecond laser interaction with unmagnetized plasma slab and symmetric modes for enhanced terahertz field generation","authors":"Himank Sagar, Suresh C. Sharma","doi":"10.1002/ctpp.202400020","DOIUrl":"https://doi.org/10.1002/ctpp.202400020","url":null,"abstract":"We consider the excitation of terahertz (THz) electromagnetic fields by interaction of radially polarized laser pulses of diverse profiles with a homogenous plasma density slab. We utilize the properties of the laser pulse to generate THz fields in a plasma slab. It is shown that the radial ponderomotive force exerted by laser imparts an oscillatory velocity to plasma electrons and drives a nonlinear current in azimuthal direction exciting THz electromagnetic fields in the plasma slab. The dependence of the excited radial electric field and azimuthal magnetic field on axial and radial parameters of the plasmas lab, as well as on the slab thickness and laser pulse width size, is investigated. It is demonstrated that the terahertz fields are generated most efficiently with a frequency close to the plasma frequency. It is also shown that the intensity of the excited fields may be optimized and controlled by the plasma slab and laser pulse parameters. Rectangular‐triangular, super‐Gaussian, and sinusoidal lasers exhibit a significantly steeper radial gradient of ponderomotive potential in comparison with other laser profiles, and excite intense radial electric fields and generate azimuthal magnetic fields in plasma slab. The numerical results closely follow the scaling laws and match with previous experimental and simulation results.","PeriodicalId":10700,"journal":{"name":"Contributions to Plasma Physics","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141372706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
<p>In order to simulate hydrogen (H) plasma in the linear plasma device NAGDIS-II, we have modified the fluid code LINDA-NU to allow the simultaneous calculation of multiple ion species consisting of hydrogen atomic ions (<span></span><math>