{"title":"Techniques to generate intense isolated attosecond pulses from relativistic plasma mirrors","authors":"H. Kallala, F. Qu'er'e, H. Vincenti","doi":"10.1103/PHYSREVRESEARCH.2.043007","DOIUrl":"https://doi.org/10.1103/PHYSREVRESEARCH.2.043007","url":null,"abstract":"Doppler harmonic generation of a high-power laser on a relativistic plasma mirror is a promising path to produce bright attosecond light bursts. Yet, a major challenge has been to find a way to generate isolated attosecond pulses, better suited to timed-resolved experiments, rather than trains of pulses. A promising technique is the attosecond lighthouse effect, which consists in imprinting different propagation directions to successive attosecond pulses of the train, and then spatially filtering one pulse in the far field. However, in the relativistic regime, plasma mirrors get curved by the radiation pressure of the incident laser and thus focus the generated harmonic beams. This increases the harmonic beam divergence and makes it difficult to separate the attosecond pulses angularly. In this article, we propose two novel techniques readily applicable in experiments to significantly reduce the divergence of Doppler harmonics, and achieve the generation of isolated attosecond pulses from the lighthouse effect without requiring few-cycle laser pulses. Their validity is demonstrated using state-of-the-art simulations, which show that isolated attosecond pulses with $10$TW peak power in the X-UV range can be generated with PW-class lasers. These techniques can equally be applied to other generation mechanisms to alleviate the constraints on the duration on the laser pulses needed to generate isolated attosecond pulses.","PeriodicalId":8461,"journal":{"name":"arXiv: Plasma Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80738802","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ren-Tong Guo, Yu Wang, R. Shaisultanov, F. Wan, Zhongfeng Xu, Yue-Yue Chen, K. Hatsagortsyan, Jian-Xing Li
{"title":"Stochasticity in radiative polarization of ultrarelativistic electrons in an ultrastrong laser pulse","authors":"Ren-Tong Guo, Yu Wang, R. Shaisultanov, F. Wan, Zhongfeng Xu, Yue-Yue Chen, K. Hatsagortsyan, Jian-Xing Li","doi":"10.1103/PHYSREVRESEARCH.2.033483","DOIUrl":"https://doi.org/10.1103/PHYSREVRESEARCH.2.033483","url":null,"abstract":"Stochasticity effects in the spin (de)polarization of an ultrarelativistic electron beam during photon emissions in a counterpropoagating ultrastrong focused laser pulse in the quantum radiation reaction regime are investigated. We employ a Monte Carlo method to describe the electron dynamics semiclassically, and photon emissions as well as the electron radiative polarization quantum mechanically. While in the latter the photon emission is inherently stochastic, we were able to identify its imprints in comparison with the new developed semiclassical stochasticity-free method of radiative polarization applicable in the quantum regime. With an initially spin-polarized electron beam, the stochastic spin effects are seen in the dependence of the depolarization degree on the electron scattering angle and the electron final energy (spin stochastic diffusion). With an initially unpolarized electron beam, the spin stochasticity is exhibited in enhancing the known effect of splitting of the electron beam along the propagation direction into two oppositely polarized parts by an elliptically polarized laser pulse. The considered stochasticity effects for the spin are observable with currently achievable laser and electron beam parameters.","PeriodicalId":8461,"journal":{"name":"arXiv: Plasma Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75010056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. A. Davis, W. Angermeier, R. Hermsmeier, T. White
{"title":"Ion modes in dense ionized plasmas through nonadiabatic molecular dynamics","authors":"R. A. Davis, W. Angermeier, R. Hermsmeier, T. White","doi":"10.1103/PHYSREVRESEARCH.2.043139","DOIUrl":"https://doi.org/10.1103/PHYSREVRESEARCH.2.043139","url":null,"abstract":"We perform non-adiabatic simulations of warm dense aluminum based on the electron-force field (EFF) variant of wave-packet molecular dynamics. Comparison of the static ion-ion structure factor with density functional theory is used to validate the technique across a range of temperatures and densities spanning the warm dense matter regime. Differences in the dynamic structure factor and dispersion relation between adiabatic and non-adiabatic techniques suggest that the explicit inclusion of electrons is necessary to fully capture the low frequency dynamics of the response function.","PeriodicalId":8461,"journal":{"name":"arXiv: Plasma Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79151947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Pustylnik, B. Klumov, M. Rubin-Zuzic, A. Lipaev, V. Nosenko, D. Erdle, A. Usachev, A. Zobnin, V. Molotkov, G. Joyce, H.M.Thomas, M. Thoma, O. Petrov, V. Fortov, O.Kononenko Institut fur Materialphysik im Weltraum, Deutsche Forschungsanstalt für Luft und Raumfahrt, G. I. F. H. Temperatures, R. A. O. Sciences, Russia Ural Federal University, R. I. F. T. Physics, Technology, Russia I. Physikalisches Institut, Justus-Liebig-University Giessen, Giessen, Germany Gagarin Research, Test Cosmonaut Training Center, Russia.
{"title":"Three-dimensional structure of a string-fluid complex plasma","authors":"M. Pustylnik, B. Klumov, M. Rubin-Zuzic, A. Lipaev, V. Nosenko, D. Erdle, A. Usachev, A. Zobnin, V. Molotkov, G. Joyce, H.M.Thomas, M. Thoma, O. Petrov, V. Fortov, O.Kononenko Institut fur Materialphysik im Weltraum, Deutsche Forschungsanstalt für Luft und Raumfahrt, G. I. F. H. Temperatures, R. A. O. Sciences, Russia Ural Federal University, R. I. F. T. Physics, Technology, Russia I. Physikalisches Institut, Justus-Liebig-University Giessen, Giessen, Germany Gagarin Research, Test Cosmonaut Training Center, Russia.","doi":"10.1103/PHYSREVRESEARCH.2.033314","DOIUrl":"https://doi.org/10.1103/PHYSREVRESEARCH.2.033314","url":null,"abstract":"Three-dimensional structure of complex (dusty) plasmas was investigated under long-term microgravity conditions in the International-Space-Station-based Plasmakristall-4 facility. The microparticle suspensions were confined in a polarity-switched dc discharge. The experimental results were compared to the results of the molecular dynamics simulations with the interparticle interaction potential represented as a superposition of isotropic Yukawa and anisotropic quadrupole terms. Both simulated and experimental data exhibited qualitatively similar structural features indicating the bulk liquid-like order with the inclusion of solid-like strings aligned with the axial electric field. Individual strings were identified and their size spectrum was calculated. The decay rate of the size spectrum was found to decrease with the enhancement of string-like structural features.","PeriodicalId":8461,"journal":{"name":"arXiv: Plasma Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83719161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
F. Artola, K. Lackner, Gta Guido Huijsmans, M. Hoelzl, E. Nardon, A. Loarte
{"title":"Understanding the reduction of the edge safety factor during hot VDEs and fast edge cooling events","authors":"F. Artola, K. Lackner, Gta Guido Huijsmans, M. Hoelzl, E. Nardon, A. Loarte","doi":"10.1063/1.5140230","DOIUrl":"https://doi.org/10.1063/1.5140230","url":null,"abstract":"In the present work a simple analytical approach is presented in order to clarify the physics behind the edge current density behaviour of a hot plasma entering in contact with a resistive conductor. When a plasma enters in contact with a highly resistive wall, large current densities appear at the edge of the plasma. The model shows that this edge current originates from the plasma response, which attempts to conserve the poloidal magnetic flux ($Psi$) when the outer current is being lost. The loss of outer current is caused by the high resistance of the outer current path compared to the plasma core resistance. The resistance of the outer path may be given by plasma contact with a very resistive structure or by a sudden decrease of the outer plasma temperature (e.g. due to a partial thermal quench or due to a cold front penetration caused by massive gas injection). For general plasma geometries and current density profiles the model shows that given a small change of minor radius ($delta a$) the plasma current is conserved to first order ($delta I_p = 0 + mathcal{O}(delta a^2)$). This conservation comes from the fact that total inductance remains constant ($delta L = 0$) due to an exact compensation of the change of external inductance with the change of internal inductance ($delta L_text{ext}+delta L_text{int} = 0$). As the total current is conserved and the plasma volume is reduced, the edge safety factor drops according to $q_a propto a^2/I_p$. Finally the consistency of the resulting analytical predictions is checked with the help of free-boundary MHD simulations.","PeriodicalId":8461,"journal":{"name":"arXiv: Plasma Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87121522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nidhi Rathee, A. Mukherjee, R. Trines, S. Sengupta
{"title":"Wavebreaking amplitudes in warm, inhomogeneous plasmas revisited","authors":"Nidhi Rathee, A. Mukherjee, R. Trines, S. Sengupta","doi":"10.1063/5.0033658","DOIUrl":"https://doi.org/10.1063/5.0033658","url":null,"abstract":"The effect of electron temperature on the space-time evolution of nonlinear plasma oscillations in an inhomogeneous plasma is studied using an in-house developed one-dimensional particle-in-cell (PIC) code. In contrast to the conventional wisdom, it is found that for an inhomogeneous plasma, there exists a critical value of electron temperature beyond which wave breaking does not occur. This novel result, which is of relevance to present day laser plasma experiments, has been explained on the basis of interplay between electron thermal pressure and background inhomogeneity.","PeriodicalId":8461,"journal":{"name":"arXiv: Plasma Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-02-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90663108","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
F. Wan, Yu Wang, Ren-Tong Guo, Yue-Yue Chen, R. Shaisultanov, Zhongfeng Xu, K. Hatsagortsyan, C. Keitel, Jian-Xing Li
{"title":"High-energy \u0000γ\u0000-photon polarization in nonlinear Breit-Wheeler pair production and \u0000γ\u0000 polarimetry","authors":"F. Wan, Yu Wang, Ren-Tong Guo, Yue-Yue Chen, R. Shaisultanov, Zhongfeng Xu, K. Hatsagortsyan, C. Keitel, Jian-Xing Li","doi":"10.1103/PHYSREVRESEARCH.2.032049","DOIUrl":"https://doi.org/10.1103/PHYSREVRESEARCH.2.032049","url":null,"abstract":"The interaction of an unpolarized electron beam with a counterpropagating ultraintense linearly polarized laser pulse is investigated in the quantum radiation-dominated regime. We employ a semiclassical Monte Carlo method to describe spin-resolved electron dynamics, photon emissions and polarization, and pair production. Abundant high-energy linearly polarized gamma photons are generated intermediately during this interaction via nonlinear Compton scattering, with an average polarization degree of more than 50%, which further interacting with the laser fields produce electron-positron pairs due to nonlinear Breit-Wheeler process. The photon polarization is shown to significantly affect the pair yield by a factor beyond 10%. The considered signature of the photon polarization in the pair's yield can be experimentally identified in a prospective two-stage setup. Moreover, the signature can serve also for the polarimetry of high-energy high-flux gamma photons with a resolution well below 1% with currently achievable laser facilities.","PeriodicalId":8461,"journal":{"name":"arXiv: Plasma Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90461568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}