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100-GeV large scale laser plasma electron acceleration by a multi-PW laser

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Chinese Optics Letters 2013年第1期11卷 87-101页

作者：中岛一久卢海洋赵学燕沈百飞李儒新徐至晨 Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences High Energy Accelerator Research Organization (KEK) 1-1 Oho Shanghai Jiao Tong University

We present three possible design options of laser plasma acceleration （LPA） for reaching a 100-GeV level energy by means of a multi-petawatt laser such as the 3.5-k J, 500-fs PETawatt Aquitane Laser （PETAL） at French Alternative Energies and Atomic Energy Commission （CEA）. Based on scaling of laser wakefield acceleration in the quasi-linear regime with the normalized vector potential a0 = 1.4（1.6）, acceleration to 100 （130） GeV requires a 30-m-long plasma waveguide operated at the plasma density ne ≈ 7 ×10^15 c^m-3 with a channel depth An/ne = 20%, while a nonlinear laser wakefield accelerator in the bubble regime with a0 〉/ 2 can reach 100 GeV approximately in a 36/a0-m-long plasma through self-guiding. The third option is a hybrid concept that employs a ponderomotive channel created by a long leading pulse for guiding a short trailing driving laser pulse. The detail parameters for three options are evaluated, optimizing the operating plasma density at which a given energy gain is obtained over the dephasing length and the matched conditions for propagation of relativistic laser pulses in plasma channels, including the self-guiding. For the production of high-quality beams with 1%-level energy spread and a llr-mm-mrad- level transverse normalized emittance at 100-MeV energy, a simple scheme based on the ionization-induced injection mechanism may be conceived. We investigate electron beam dynamics and effects of synchrotron radiation due to betatron motion by solving the beam dynamics equations on energy and beam radius numerically. For the bubble regime case with a0 = 4, radiative energy loss becomes 10% at the maximum energy of 90 GeV.

关键词： Electron beams Energy dissipation Laser pulses Particle beam dynamics plasma accelerators plasma density plasma interactions plasma waves

The Electromagnetic Instability in Electron Flow with Ion Background

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plasma Science and Technology 2010年第5期12卷 523-528页

作者：高敏陈少永唐昌建彭晓东 College of Physical Science and Technology Sichuan University Southwest Institution of Physics Center for Fusion Science

Electromagnetic （EM） behavior and instability resulting from the interaction between EM wave and plasma wave are analyzed based on linear perturbation theory. It is shown that the instability is caused by the the coupling between high frequency electromagnetic field and electron transverse oscillation derived from the deflection of electron longitudinal oscillation due to self-produced magnetic field. The influences of the self-produced magnetic field and plasma density on the ihstability are studied. In addition, characteristics of EM wave propagation at different angles are investigated. The present results are of significance to new type plasma radiation source, ion accelerator and plasma diagnostic techniques.

关键词： motional plasma plasma waves electromagnetic instability

Non-steady interaction of plasma with aircraft in its near wake region

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Chinese Physics B 2007年第1期16卷 179-185页

作者：胡涛平罗青 College of Information Science and Technology Nanjing Forestry University Nanjing 210037 China Department of Physics Nanjing Xiaozh uang College Nanjing 210017 China

Non-steady interactions between plasmas and aircraft in its near wake region are investigated in detail. Under the non-static limit, a set of equations that describe these interactions are obtained. The results of the numerical simulation show that the cavitons of transverse plasmas are excited and density cavitons appear when the envelope of plasma becomes sufficiently intensive. This is very important for detecting the moving body that has a ＇stealth＇ characteristic.

关键词： ionosphere plasma waves plasma interaction

Numerical Study of Spontaneous Outspread of Large-Scale Surface-Wave plasma Excited by Slot-Antenna Array

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Chinese Physics Letters 2009年第3期26卷 170-173页

作者：蓝朝晖胡希伟刘明海 College of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuhan 430074

The spontaneous outspread of surface-wave plasma studied using a time-stepping self-consistent model. （SWP） towards the edge of large-scale quartz window is The performances of three different types of slot-antenna arrays are compared, and the electron density distributions for each array at different stages are presented. The results show that slotting along both x and y directions can be helpful to the outspread and can thus enhance the uniformity of SWP. Meanwhile, when we use such an array, the absorption rate of input microwave power can reach more than 83%.

关键词： plasma waves SURFACE waves (Fluids) EXCITED state chemistry SLOT antennas ELECTRON distribution NUMERICAL analysis

Recent progress in Chinese polar upper-atmospheric physics research: review of research advances supported by the Chinese Arctic and Antarctic expeditions

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Advances in Polar Science 2016年第4期27卷 219-232页

作者： HE Fang HU Hongqiao YANG Huigen ZHANG Beichen HUANG Dehong LIU Yonghua HU Zejun LIU Jianjun SOA Key Laboratory for Polar Science Polar Research Institute of China

It has been more than 30 years since the first Chinese Antarctic Expedition took place. Polar upper atmospheric observations started at this time. First began at Great Wall Station and then at Zhongshan Station in Antarctica, and later in the Arctic at Yellow River Station, Kjell Henriksen Observatory on Svalbard, and at the China-Iceland Joint Aurora Observatory in Iceland. In this paper, we reviewed the advances in polar upper atmosphere physics （UAP） based on the Chinese national Arctic and Antarctic research over the last five years. These included newly deployed observatories and research instruments in the Arctic and Antarctic; and new research findings, from grotmd-based observations, about polar ionosphere dynamics, aurora and particle precipitation, polar plasma convection, geomagnetic pulsations and space plasma waves, space weather in the polar regions, simulations of the polar ionosphere-magnetosphere. In conclusion, suggestions were made for future polar upper atmosphere physics research in China.

关键词： upper-atmospheric physics research advances polar ionosphere aurora particle precipitation plasmaconvection plasma waves space weather

Efficacy of Hilbert-Huang Transform (HHT) in the Analysis of Instantaneous Low Frequency waves of Magnetosheath

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International Journal of Geosciences 2016年第1期7卷 11-19页

作者： Ekong U. Nathaniel Nyakno J. George Jewel I. Ibanga Aniekan M. Ekanem Department of Physics Akwa Ibom State University Ikot Akpaden Nigeria

The flow of supersonic plasma is accompanied by a highly thermalized region called the Magnetoshealth found after the bow shock. Enclosed within this region are different wave modes associated with classes of boundaries which have been determined by different methods. The efficacy of Hilbert-Huang transform (HHT) is based on the conditionality of allowing for the local analysis of frequencies, which presents the physical meaning of the original signal at that instant. The observed data have been taken from Cluster II Fluxgate Magnetometer (FGM) instrument that provides advantage for the analysis in three dimensions. The result compares favourably with instantaneous frequencies computed using simple Hilbert transform (SHT) with electric field measurements of Cluster II mission already carried out in literatures. The result of this study has shown that HHT provides the best applicability in the magnetosheath data analysis than the wavelet and Fast Fourier Transform (FFT). The application of HHT based on its advantages over other methods is viewed to be very critical in the analysis of multi-frequency signals where different frequencies could be determined distinctively at a point.

关键词： plasma waves Instantaneous Frequency Empirical Mode Decomposition (EMD) Hilbert-Huang Transform (HHT)