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Suppression of stimulated Brillouin and Raman scatterings using an alternating frequency laser and transverse magnetic fields
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作者 程瑞锦 李晓旬 +11 位作者 王清 刘德基 黄卓明 吕帅宇 周远志 张舒童 李雪铭 陈祖杰 王强 刘占军 曹莉华 郑春阳 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期545-553,共9页
A novel scheme to suppress both stimulated Brillouin scattering(SBS) and stimulated Raman scattering(SRS) by combining an alternating frequency(AF) laser and a transverse magnetic field is proposed. The AF laser allow... A novel scheme to suppress both stimulated Brillouin scattering(SBS) and stimulated Raman scattering(SRS) by combining an alternating frequency(AF) laser and a transverse magnetic field is proposed. The AF laser allows the laser frequency to change discretely and alternately over time. The suppression of SBS is significant as long as the AF difference is greater than the linear growth rate of SBS or the alternating time of the laser frequency is shorter than the linear growth time of SBS. However, the AF laser proves ineffective in suppressing SRS, which usually has a much higher linear growth rate than SBS. To remedy that, a transverse magnetic field is included to suppress the SRS instability. The electrons trapped in the electron plasma waves(EPWs) of SRS can be accelerated by the surfatron mechanism in a transverse magnetic field and eventually detrapped. While continuously extracting energy from EPWs, the EPWs are dissipated and the kinetic inflation of SRS is suppressed. The one-dimensional particle-in-cell simulation results show that both SBS and SRS can be effectively suppressed by combining the AF laser with a transverse magnetic field with tens of Tesla. The total reflectivity can be dramatically reduced by more than one order of magnitude. These results provide a potential reference for controlling SBS and SRS under the related parameters of inertial confinement fusion. 展开更多
关键词 stimulated Brillouin scattering stimulated Raman scattering alternating frequency laser transverse magnetic field
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Model of self-generated magnetic field generation from relativistic laser interaction with solid targets
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作者 严睿 邹德滨 +9 位作者 赵娜 杨晓虎 蒋祥瑞 胡理想 徐新荣 周泓宇 余同普 卓红斌 邵福球 银燕 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第5期511-517,共7页
Generation of self-generated annular magnetic fields at the rear side of a solid target driven by relativistic laser pulse is investigated by using theoretical analysis and particle-in-cell simulations.The spatial str... Generation of self-generated annular magnetic fields at the rear side of a solid target driven by relativistic laser pulse is investigated by using theoretical analysis and particle-in-cell simulations.The spatial strength distribution of magnetic fields can be accurately predicted by calculating the net flow caused by the superposition of source flow and return flow of hot electrons.The theoretical model established shows good agreement with the simulation results,indicating that the magnetic-field strength scales positively to the temperature of hot electrons.This provides us a way to improve the magnetic-field generation by using a micro-structured plasma grating in front of the solid target.Compared with that for a common flat target,hot electrons can be effectively heated with the well-designed grating size,leading to a stronger magnetic field.The spatial distribution of magnetic fields can be modulated by optimizing the grating period and height as well as the incident angle of the laser pulse. 展开更多
关键词 self-generated magnetic field laser solid-target interaction micro-structured plasma grating
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Revolutionizing plasmonic platform via magnetic field-assisted confined ultrafast laser deposition of high-density,uniform,and ultrafine nanoparticle arrays
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作者 Jin Xu Lingfeng Wang +5 位作者 Peilin Yang Haoqing Jiang Huai Zheng Licong An Xingtao Liu Gary J Cheng 《International Journal of Extreme Manufacturing》 SCIE EI CAS CSCD 2024年第3期428-438,共11页
The remarkable capabilities of 2D plasmonic surfaces in controlling optical waves havegarnered significant attention.However,the challenge of large-scale manufacturing of uniform,well-aligned,and tunable plasmonic sur... The remarkable capabilities of 2D plasmonic surfaces in controlling optical waves havegarnered significant attention.However,the challenge of large-scale manufacturing of uniform,well-aligned,and tunable plasmonic surfaces has hindered their industrialization.To address this,we present a groundbreaking tunable plasmonic platform design achieved throughmagnetic field(MF)assisted ultrafast laser direct deposition in air.Through precise control of metal nanoparticles(NPs),with cobalt(Co)serving as the model material,employing an MF,and fine-tuning ultrafast laser parameters,we have effectively converted coarse and non-uniform NPs into densely packed,uniform,and ultrafine NPs(~3 nm).This revolutionary advancement results in the creation of customizable plasmonic‘hot spots,’which play a pivotal role insurface-enhanced Raman spectroscopy(SERS)sensors.The profound impact of this designable plasmonic platform lies in its close association with plasmonic resonance and energyenhancement.When the plasmonic nanostructures resonate with incident light,they generate intense local electromagnetic fields,thus vastly increasing the Raman scattering signal.This enhancement leads to an outstanding 2–18 fold boost in SERS performance and unparalleled sensing sensitivity down to 10^(-10)M.Notably,the plasmonic platform also demonstratesrobustness,retaining its sensing capability even after undergoing 50 cycles of rinsing andre-loading of chemicals.Moreover,this work adheres to green manufacturing standards,making it an efficient and environmentally friendly method for customizing plasmonic‘hot spots’inSERS devices.Our study not only achieves the formation of high-density,uniform,and ultrafine NP arrays on a tunable plasmonic platform but also showcases the profound relation betweenplasmonic resonance and energy enhancement.The outstanding results observed in SERS sensors further emphasize the immense potential of this technology for energy-relatedapplications,including photocatalysis,photovoltaics,and clean water,propelling us closer to a sustainable and cleaner future. 展开更多
关键词 magnetic field manipulation laser deposition metasurface SERS
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A 7 T Pulsed Magnetic Field Generator for Magnetized Laser Plasma Experiments 被引量:1
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作者 胡广月 梁亦寒 +4 位作者 宋法伦 袁鹏 王雨林 赵斌 郑坚 《Plasma Science and Technology》 SCIE EI CAS CSCD 2015年第2期134-140,共7页
A pulsed magnetic field generator was developed to study the effect of a magnetic field on the evolution of a laser-generated plasma. A 40 kV pulsed power system delivered a fast (-230 ns), 55 kA current pulse into ... A pulsed magnetic field generator was developed to study the effect of a magnetic field on the evolution of a laser-generated plasma. A 40 kV pulsed power system delivered a fast (-230 ns), 55 kA current pulse into a single-turn coil surrounding the laser target, using a capacitor bank of 200 nF, a laser-triggered switch and a low-impedance strip transmission line. A one-dimensional uniform 7 T pulsed magnetic field was created using a Helmholtz coil pair with a 6 mm diameter. The pulsed magnetic field was controlled to take effect synchronously with a nanosecond heating laser beam, a femtosecond probing laser beam and an optical Intensified Charge Coupled Device (ICCD) detector. The preliminary experiments demonstrate bifurcation and focusing of plasma expansion in a transverse magnetic field. 展开更多
关键词 magnetized laser plasma pulsed strong magnetic field
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Influence of a Static Magnetic Field on Laser Induced Tungsten Plasma in Air 被引量:2
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作者 吴鼎 刘平 +2 位作者 孙立影 海然 丁洪斌 《Plasma Science and Technology》 SCIE EI CAS CSCD 2016年第4期364-369,共6页
In this work,laser induced tungsten plasma has been investigated in the absence and presence of 0.6 T static transverse magnetic field at atmospheric pressure in air.The spectroscopic characterization of laser induced... In this work,laser induced tungsten plasma has been investigated in the absence and presence of 0.6 T static transverse magnetic field at atmospheric pressure in air.The spectroscopic characterization of laser induced tungsten plasma was experimentally studied using space-resolved emission spectroscopy.The atomic emission lines of tungsten showed a significant enhancement in the presence of a magnetic field,while the ionic emission lines of tungsten presented little change.Temporal variation of the optical emission lines of tungsten indicated that the atomic emission time in the presence of a magnetic field was longer than that in the absence of a magnetic field,while no significant changes occurred for the ionic emission time.The spatial resolution of optical emission lines of tungsten demonstrated that the spatial distribution of atoms and ions were separated.The influence of a magnetic field on the spatial distribution of atoms was remarkable,whereas the spatial distribution of ions was little influenced by the magnetic field.The different behaviors between ions and atoms with and without magnetic field in air were related to the various atomic processes especially the electrons and ions recombination process during the plasma expansion and cooling process. 展开更多
关键词 laser-induced breakdown spectroscopy magnetic field tungsten plasma spatial evolution
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Quasistatic magnetic fields generated by a nonrelativistic intense laser pulse in uniform underdense plasma
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作者 张蕾 董全力 +2 位作者 王首钧 盛政明 张杰 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第7期596-602,共7页
Quasistatic magnetic fields generated by nonrelativistic intense linearly polarized (LP) and circularly polarized (CP) laser pulses in an initially uniform underdense plasma in the collision-dominated limit are in... Quasistatic magnetic fields generated by nonrelativistic intense linearly polarized (LP) and circularly polarized (CP) laser pulses in an initially uniform underdense plasma in the collision-dominated limit are investigated analytically. Using a selfconsistent analytical model, we perform a detailed derivation of quasistatic magnetic fields in the laser pulse envelope in the collision-dominated limit to obtain exact analytical expressions for magnetic fields and discuss the dependence of magnetic fields on laser and plasma parameters. Equations for quasistatic magnetic fields including both axial componentBz and the azimuthal one Be are derived simultaneously from such a selfconsistent model. The dependence of quasistatic magnetic field on incident laser intensity, transverse focused radius of laser pulse, electron density and electron temperature is discussed. 展开更多
关键词 quasistatic magnetic field laser PLASMA
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Axial magnetic field effect in numerical analysis of high power Cherenkov free electron laser
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作者 F BazoubAND B Maraghechi 《Chinese Physics B》 SCIE EI CAS CSCD 2019年第6期176-183,共8页
Cherenkov free electron laser(CFEL) is simulated numerically by using the single particle method to optimize the electron beam. The electron beam is assumed to be moving near the surface of a flat dielectric slab alon... Cherenkov free electron laser(CFEL) is simulated numerically by using the single particle method to optimize the electron beam. The electron beam is assumed to be moving near the surface of a flat dielectric slab along a growing radiation. The set of coupled nonlinear differential equations of motion is solved to study the electron dynamics. For three sets of parameters, in high power CFEL, it is found that an axial magnetic field is always necessary to keep the electron beam in the interaction region and its optimal strength is reported for each case. At the injection point, the electron beam’s distance above the dielectric surface is kept at a minimum value so that the electrons neither hit the dielectric nor move away from it to the weaker radiation fields and out of the interaction region. The optimal electron beam radius and current are thereby calculated. This analysis is in agreement with two previous numerical studies for a cylindrical waveguide but is at odds with analytical treatments of a flat dielectric that does not use an axial magnetic field. This is backed by an interesting physical reasoning. 展开更多
关键词 Cherenkov free electron laser axial magnetic field flat dielectric slab electron beam
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Electron-Cyclotron Laser Using Free-Electron Two-Quantum Stark Radiation in a Strong Uniform Axial Magnetic Field and an Alternating Axial Electric Field in a Voltage-Supplied Pill-Box Cavity
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作者 S.H.Kim 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第3期56-59,共4页
We consider the radiation from the beam electrons traveling in a strong uniform axial magnetic field and an axial alternating electric field of wavelength Aw generated by a voltage-supplied pill-box cavity. The beam e... We consider the radiation from the beam electrons traveling in a strong uniform axial magnetic field and an axial alternating electric field of wavelength Aw generated by a voltage-supplied pill-box cavity. The beam electrons emit genuine laser radiation that propagates only in the axial direction through free-electron two- quantum Stark radiation. We find that laser radiation takes place only at the expense of the axial kinetic energy when Aw 〈〈 c/(ωc/γ), where ωc/γ is the relativistic electron--cyclotron frequency. We formulate the laser power based on quantum-wiggler electrodynamics, and envision a laser of length lore with estimated power 0.1 GW/(kA) in the 10-4 cm wavelength range. 展开更多
关键词 of on in that Electron-Cyclotron laser Using Free-Electron Two-Quantum Stark Radiation in a Strong Uniform Axial magnetic field and an Alternating Axial Electric field in a Voltage-Supplied Pill-Box Cavity is STARK
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Fabrication and absolute calibration of B-dot probe for magnetic field measurement on a high power laser facility 被引量:1
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作者 Longyu KUANG Feibiao XUE +10 位作者 Longfei JING Ruizhen YU Huabing DU Tao YI Tingshuai LI Hang LI Yi YU Feng WANG Shaoen JIANG Guangyue HU Jian ZHENG 《Plasma Science and Technology》 SCIE EI CAS CSCD 2020年第8期71-75,共5页
The fabrication and absolute calibration of a B-dot probe is employed to measure the pulsed magnetic field at the Shenguang-Ⅱhigh power laser facility.Copper enameled silk with a cross section diameter of 0.1 mm is u... The fabrication and absolute calibration of a B-dot probe is employed to measure the pulsed magnetic field at the Shenguang-Ⅱhigh power laser facility.Copper enameled silk with a cross section diameter of 0.1 mm is used to wind the one-turn coil with a 1 mm diameter.Two coils are paired and reversely linked to their respective circuits to form a differential B-dot probe that is sealed in and protected by a quartz shell.This B-dot probe is experimentally calibrated and then used to measure the pulsed magnetic field in laser targeting experiments at the Shenguang-Ⅱhigh power laser facility.Signals show a high performance of this B-dot probe.The common mode noise can be effectively canceled out by the differential pair.The magnetic field of over 300 T can be extrapolated at the location close to the target. 展开更多
关键词 B-dot magnetic field DIAGNOSTIC laser TARGETING
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Laser-field-induced magnon amplification in a magnetic semiconductor quantum well under an external magnetic field
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作者 Peng FengPhysics Department, University of Science and Technology Beijing, Beijing 100083, China 《Journal of University of Science and Technology Beijing》 CSCD 2003年第5期69-72,共4页
The laser-field induced magnon amplification in a magnetic semiconductorquantum well under an external magnetic field was discussed, it is shown that when the laserfrequency is near to the electron cyclotron frequency... The laser-field induced magnon amplification in a magnetic semiconductorquantum well under an external magnetic field was discussed, it is shown that when the laserfrequency is near to the electron cyclotron frequency, no matter how weaker the laser field is, themagnon amplification always occurs. In case of fixed laser frequency, the optical absorption ofmagnons obeys the definite selection rule to the laser field strength. The rate of change of magnonoccupation is calculated, and the amplification condition is given. 展开更多
关键词 magnon amplification magnetic semiconductor quantum well laser field
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Influence of a Static Magnetic Field on Beam Emittance in Laser Wakefield Acceleration
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作者 Mathieu Drouin Alain Bourdier +1 位作者 Quentin Harry Sébastien Rassou 《Journal of Modern Physics》 2012年第12期1991-1997,共7页
The enhancement of trapping and the optimization of beam quality are two key issues of Laser Wakefield Acceleration (LWFA). The effect of a homogenous constant magnetic field B0, parallel to the direction of propagati... The enhancement of trapping and the optimization of beam quality are two key issues of Laser Wakefield Acceleration (LWFA). The effect of a homogenous constant magnetic field B0, parallel to the direction of propagation of the pump pulse, is studied in the blowout regime via 2Dx3Dv Particle-In-Cell simulations. Electrons are injected into the wake using a counter-propagating low amplitude laser. Transverse currents are generated at the rim of the bubble, which results in the amplification of the B0 field at the rear of the bubble. Therefore the dynamics of the beam is modified, the main effect is the reduction of the transverse emittance when B0 is raised. Depending on beam loading effects the low energy tail, observed in the non-magnetized case, can be suppressed when B0 is applied, which provides a mono-energetic beam. 展开更多
关键词 laser WAKEfield ACCELERATION magnetic field BEAM EMITTANCE BEAM LOADING
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Automatic compensation of magnetic field for a rubidium space cold atom clock 被引量:5
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作者 李琳 吉经纬 +5 位作者 任伟 赵鑫 彭向凯 项静峰 吕德胜 刘亮 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第7期192-195,共4页
When the cold atom clock operates in microgravity around the near-earth orbit, its performance will be affected by the fluctuation of magnetic field. A strategy is proposed to suppress the fluctuation of magnetic fiel... When the cold atom clock operates in microgravity around the near-earth orbit, its performance will be affected by the fluctuation of magnetic field. A strategy is proposed to suppress the fluctuation of magnetic field by additional coils, whose current is changed accordingly to compensate the magnetic fluctuation by the linear and incremental compensation. The flight model of the cold atom clock is tested in a simulated orbital magnetic environment and the magnetic field fluctuation in the Ramsey cavity is reduced from 17 nT to 2 nT, which implied the uncertainty due to the second order Zeeman shift is reduced to be less than 2×10^(-16). In addition, utilizing the compensation, the magnetic field in the trapping zone can be suppressed from 7.5 μT to less than 0.3 μT to meet the magnetic field requirement of polarization gradients cooling of atoms. 展开更多
关键词 laser cooling space cold atom clock magnetic field compensation
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Laser additive manufacturing of strong and ductile Al-12Si alloy under static magnetic field 被引量:3
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作者 R.Wang J.Wang +8 位作者 L.M.Lei S.Yu T.Hu S.S.Shuai S.Z.Xu Z.H.Cao X.P.Li C.Y.Chen Z.M.Ren 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2023年第32期101-112,共12页
Rapid cooling and solidification during laser additive manufacturing(LAM)can produce ultra-fine microstructure with higher strength.However,the non-uniform cell/grain structure can easily result in early stress concen... Rapid cooling and solidification during laser additive manufacturing(LAM)can produce ultra-fine microstructure with higher strength.However,the non-uniform cell/grain structure can easily result in early stress concentration and fracture during deformation,which remains a major challenge for the LAM field.Using Al-12Si as the model alloy,we employed the external static magnetic field(SMF)to modulate the laser powder bed fusion process(L-PBF),demonstrating a uniform microstructure with a refined cell structure.The mechanical properties show that the SMF can produce a combination of high tensile strength of 451.4±0.5 MPa and large uniform elongation of 10.4%±0.79%,which are superior to those of previously-reported Al-Si alloys with post-treatment or element alloying.The mechanism analysis based on multi-scale simulation reveals the determining role of SMF in rapid solidification,and this method is applicable to the microstructure control of other metallic materials during LAM. 展开更多
关键词 laser powder bed fusion magnetic field Al alloys Grain refinement Strengthening mechanism
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Miniature Fiber-Optic Magnetic Field Sensor Based on Ampere Force and Fiber Laser 被引量:1
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作者 Weiren CHENG Tianming LUO +2 位作者 Linghao CHENG Hao LIANG Bai-ou GUAN 《Photonic Sensors》 SCIE EI CSCD 2020年第4期291-297,共7页
A compact fiber-optic magnetic field sensor is proposed by packaging an orthogonal dual-frequency fiber grating laser and a copper wire with alternating electrical current together inside epoxy resin.The alternating c... A compact fiber-optic magnetic field sensor is proposed by packaging an orthogonal dual-frequency fiber grating laser and a copper wire with alternating electrical current together inside epoxy resin.The alternating current generates Ampere force in a magnetic field,which changes the birefringence of the fiber laser and hence tunes the frequency of the beat signal after photodetection.The magnetic flux density can then be detected by measuring the frequency change of the beat signal.The sensitivity of the sensor can be tuned with a maximum response of 35.21 kHz/kGs demonstrated.Moreover,the sensor shows good immunity to environment interference. 展开更多
关键词 Fiber laser optical magnetic field sensors fiber-optic sensors Ampere force
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Laser scaling for generation of megatesla magnetic fields by microtube implosions 被引量:1
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作者 D.Shokov M.Murakami J.J.Honrubia 《High Power Laser Science and Engineering》 SCIE CAS CSCD 2021年第4期103-111,共9页
Microtube implosions are a novel scheme to generate ultrahigh magnetic fields of the megatesla order.These implosions are driven by ultraintense and ultrashort laser pulses.Using two-and three-dimensional particle sim... Microtube implosions are a novel scheme to generate ultrahigh magnetic fields of the megatesla order.These implosions are driven by ultraintense and ultrashort laser pulses.Using two-and three-dimensional particle simulations where megatesla-order magnetic fields can be achieved,we demonstrate scaling and criteria in terms of laser parameters,such as laser intensity and laser energy,to facilitate practical experiments toward the realization of extreme physical conditions,which have yet to be realized in laboratories.Microtube implosions should provide a new platform for studies in fundamental and applied physics relevant to ultrahigh magnetic fields. 展开更多
关键词 microtube implosion megatesla magnetic field ultraintense laser
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Generation mechanism of 100 MG magnetic fields in the interaction of ultra-intense laser pulse with nanostructured target 被引量:1
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作者 J.M.Tian H.B.Cai +3 位作者 W.S.Zhang E.H.Zhang B.Du S.P.Zhu 《High Power Laser Science and Engineering》 SCIE CAS CSCD 2020年第2期50-55,共6页
Experimental and simulation data[Moreau et al.,Plasma Phys.Control.Fusion 62,014013(2019);Kaymak et al.,Phys.Rev.Lett.117,035004(2016)]indicate that self-generated magnetic fields play an important role in enhancing t... Experimental and simulation data[Moreau et al.,Plasma Phys.Control.Fusion 62,014013(2019);Kaymak et al.,Phys.Rev.Lett.117,035004(2016)]indicate that self-generated magnetic fields play an important role in enhancing the flux and energy of relativistic electrons accelerated by ultra-intense laser pulse irradiation with nanostructured arrays.A fully relativistic analytical model for the generation of the magnetic field based on electron magneto-hydrodynamic description is presented here.The analytical model shows that this self-generated magnetic field originates in the nonparallel density gradient and fast electron current at the interfaces of a nanolayered target.A general formula for the self-generated magnetic field is found,which closely agrees with the simulation scaling over the relevant intensity range.The result is beneficial to the experimental designs for the interaction of the laser pulse with the nanostructured arrays to improve laser-to-electron energy coupling and the quality of forward hot electrons. 展开更多
关键词 nanolayered target self-generated magnetic field ultra-intense laser pulse
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Laboratory astrophysics with laser-driven strong magnetic fields in China
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作者 Fei-Lu Wang Xiao-Xing Pei +13 位作者 Bo Han Hui-Gang Wei Da-Wei Yuan Gui-Yun Liang Gang Zhao Jia-Yong Zhong Zhe Zhang Bao-Jun Zhu Yan-Fei Li Fang Li Yu-Tong Li Si-Liang Zeng Shi-Yang Zou Jie Zhang 《High Power Laser Science and Engineering》 SCIE CAS CSCD 2016年第3期67-70,共4页
In this paper, the recent studies of laboratory astrophysics with strong magnetic fields in China have been reviewed.On the Shenguang-II laser facility of the National Laboratory on High-Power Lasers and Physics, a la... In this paper, the recent studies of laboratory astrophysics with strong magnetic fields in China have been reviewed.On the Shenguang-II laser facility of the National Laboratory on High-Power Lasers and Physics, a laser-driven strong magnetic field up to 200 T has been achieved. The experiment was performed to model the interaction of solar wind with dayside magnetosphere. Also the low beta plasma magnetic reconnection(MR) has been studied. Theoretically, the model has been developed to deal with the atomic structures and processes in strong magnetic field. Also the study of shock wave generation in the magnetized counter-streaming plasmas is introduced. 展开更多
关键词 Laboratory astrophysics laser strong magnetic fields
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DFB fiber laser sensor for simultaneous measurement of acoustic and magnetic fields
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作者 Rui Ma Wentao Zhang +1 位作者 Wenzhu Huang Fang Li 《Chinese Optics Letters》 SCIE EI CAS CSCD 2018年第6期24-28,共5页
A novel distributed feedback(DFB) fiber laser sensor, which can measure acoustic and magnetic fields simultaneously, is proposed. The magnetic field can be measured by detecting the change of resonant frequency of t... A novel distributed feedback(DFB) fiber laser sensor, which can measure acoustic and magnetic fields simultaneously, is proposed. The magnetic field can be measured by detecting the change of resonant frequency of the fiber laser, and the acoustic pressure can be measured by detecting the phase shift of the fiber laser. Both of the signals can be simultaneously demodulated in the frequency domain without affecting each other. Experimental studies show that the acoustic pressure sensitivity of this sensor is about-130 d B(0 dB re 1 pm∕μPa) and the sensor has a good linearity with a magnetic field sensitivity of 0.57 Hz∕mT. 展开更多
关键词 LENGTH DFB fiber laser sensor for simultaneous measurement of acoustic and magnetic fields
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Laser-Plasma Interaction in Presence of an Obliquely External Magnetic Field:Application to Laser Fusion without Radioactivity
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作者 M.Mobaraki S.Jafari 《Communications in Theoretical Physics》 SCIE CAS CSCD 2016年第8期237-243,共7页
In this paper, the nonlinear interaction of ultra-high power laser beam with fusion plasma at relativistic regime in the presence of obliquely external magnetic field has been studied. Imposing an external magnetic fi... In this paper, the nonlinear interaction of ultra-high power laser beam with fusion plasma at relativistic regime in the presence of obliquely external magnetic field has been studied. Imposing an external magnetic field on plasma can modify the density profile of the plasma so that the thermal conductivity of electrons reduces which is considered to be the decrease of the threshold energy for ignition. To achieve the fusion of Hydrogen–Boron(HB) fuel,the block acceleration model of plasma is employed. Energy production by HB isotopes can be of interest, since its reaction does not generate radioactive tritium. By using the inhibit factor in the block model acceleration of plasma and Maxwell's as well as the momentum transfer equations, the electron density distribution and dielectric permittivity of the plasma medium are obtained. Numerical results indicate that with increasing the intensity of the external magnetic field, the oscillation of the laser magnetic field decreases, while the dielectric permittivity increases. Moreover, the amplitude of the electron density becomes highly peaked and the plasma electrons are strongly bunched with increasing the intensity of external magnetic field. Therefore, the magnetized plasma can act as a positive focusing lens to enhance the fusion process. Besides, we find that with increasing θ-angle(from oblique external magnetic field) between 0 and 90°, the dielectric permittivity increases, while for θ between 90° and 180°, the dielectric permittivity decreases with increasing θ. 展开更多
关键词 laser-plasma interaction external magnetic field laser fusion HB fuel
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Magnetostrictive composite material-based polarimetric heterodyning fiber-grating laser miniature magnetic field sensor 被引量:3
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作者 何炜 程凌浩 +3 位作者 袁强 梁贻智 金龙 关柏鸥 《Chinese Optics Letters》 SCIE EI CAS CSCD 2015年第5期17-20,共4页
A novel fiber-optic magnetic field sensor is demonstrated based on a dual-polarization fiber-grating laser, which is embedded in an epoxy resin-bonded magnetostrictive composite material with doped Terfenol-D particle... A novel fiber-optic magnetic field sensor is demonstrated based on a dual-polarization fiber-grating laser, which is embedded in an epoxy resin-bonded magnetostrictive composite material with doped Terfenol-D particles. A simple structure is designed to convert the magnetic field-induced strain to transversal stress, which is applied to the fiber laser to produce beat note frequency changes for measurement purposes. The response of the proposed sensor is measured, and shows quite a good directivity and linearity with a sensitivity of 10.5 Hz/μT to the magnetic field. It also shows a large measurable range up to about 0.3 T. 展开更多
关键词 Composite materials Epoxy resins Fiber lasers Fibers magnetic fields magnetic sensors magnetISM magnetOMETERS magnetostrictive devices
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