On the marginal instability threshold condition of the aperiodic ordinary mode

2014 ◽  
Vol 21 (7) ◽  
pp. 072119 ◽  
Author(s):  
R. Schlickeiser ◽  
P. H. Yoon
Keyword(s):  
Instability Threshold ◽  
Threshold Condition ◽  
Ordinary Mode

Marginal instability threshold condition of the aperiodic ordinary mode in equal-mass plasmas

2014 ◽  
Vol 21 (10) ◽  
pp. 104504 ◽  
Author(s):  
S. Vafin ◽  
R. Schlickeiser ◽  
P. H. Yoon
Keyword(s):  
Equal Mass ◽  
Instability Threshold ◽  
Threshold Condition ◽  
Ordinary Mode

scholarly journals A universal mirror wave-mode threshold condition for non-thermal space plasma environments

2002 ◽  
Vol 9 (2) ◽  
pp. 75-78 ◽  
Author(s):  
M. P. Leubner ◽  
N. Schupfer
Keyword(s):  
Wave Mode ◽  
Instability Threshold ◽  
Velocity Space ◽  
Space Distribution ◽  
Instability Criterion ◽  
Threshold Condition ◽  
Magnetic Fluctuations ◽  
Plasma Parameters ◽  
Energy Principle ◽  
Loss Cone

Abstract. Magnetic fluctuations are recognized in a large variety of space plasmas by increasingly high resolution, in situ observations as mirror wave mode structures. A typical requirement for the excitation of mirror modes is a dominant perpendicular pressure in a high-beta plasma environment. Contrary, we demonstrate from a realistic kinetic analysis how details of the velocity space distributions are of considerable significance for the instability threshold. Introducing the most common characteristics of observed ion and electron distributions by a mixed suprathermal-loss-cone, we derive a universal mirror instability criterion from an energy principle for collisionless plasmas. As a result, the transition from two temperature Maxwellians to realistic non-thermal features provides a strong source for the generation of mirror wave mode activity, reducing drastically the instability threshold. In particular, a number of space-related examples illuminate how the specific structure of the velocity space distribution dominates as a regulating excitation mechanism over the effects related to changes in the plasma parameters.

Proton Cyclotron Instability Threshold Condition of Suprathermal Protons by Kappa Distribution

2007 ◽  
Vol 9 (5) ◽  
pp. 545-549 ◽  
Author(s):  
Xiao Fuliang ◽  
Zhou Qinghua ◽  
He Huiyong ◽  
Tang Lijun ◽  
Fang Jiayuan
Keyword(s):  
Instability Threshold ◽  
Threshold Condition ◽  
Kappa Distribution ◽  
Cyclotron Instability ◽  
Proton Cyclotron

scholarly journals Linearization threshold condition and stability analysis of a stochastic dynamic model of one-machine infinite-bus (OMIB) power systems

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Lijuan Li ◽  
Yongdong Chen ◽  
Bin Zhou ◽  
Hongliang Liu ◽  
Yongfei Liu
Keyword(s):  
Power Systems ◽  
Power System ◽  
Dynamic Model ◽  
Threshold Model ◽  
Security Evaluation ◽  
Stochastic Dynamic ◽  
Threshold Condition ◽  
Stochastic Excitation ◽  
Predictor Corrector ◽  
One Machine

AbstractWith the increase in the proportion of multiple renewable energy sources, power electronics equipment and new loads, power systems are gradually evolving towards the integration of multi-energy, multi-network and multi-subject affected by more stochastic excitation with greater intensity. There is a problem of establishing an effective stochastic dynamic model and algorithm under different stochastic excitation intensities. A Milstein-Euler predictor-corrector method for a nonlinear and linearized stochastic dynamic model of a power system is constructed to numerically discretize the models. The optimal threshold model of stochastic excitation intensity for linearizing the nonlinear stochastic dynamic model is proposed to obtain the corresponding linearization threshold condition. The simulation results of one-machine infinite-bus (OMIB) systems show the correctness and rationality of the predictor-corrector method and the linearization threshold condition for the power system stochastic dynamic model. This study provides a reference for stochastic modelling and efficient simulation of power systems with multiple stochastic excitations and has important application value for stability judgment and security evaluation.

Thresholds in Flux—the Standard for Ascertaining the Requirement of Organization for Armed Groups under International Humanitarian Law

2020 ◽  
Author(s):  
Yutaka Arai-Takahashi
Keyword(s):  
Armed Conflict ◽  
Geneva Convention ◽  
Prisoners Of War ◽  
Organizational Level ◽  
International Humanitarian Law ◽  
Threshold Condition ◽  
Special Importance ◽  
Humanitarian Law ◽  
Armed Groups ◽  
International Criminal Tribunals

Abstract The requirement of organization is supposed to be of special importance in international humanitarian law (IHL). In the situation of international armed conflict (IAC), this requirement is implicit as part of the collective conditions to be fulfilled by irregular/independent armed groups to enable their members to claim the prisoners of war status under Article 4 A(2) of the Third Geneva Convention. In a non-international armed conflict (NIAC), the eponymous requirement serves, alongside the requirement of intensity of violence, as the threshold condition for ascertaining the onset of a NIAC. While the requirement of organization has not caused much of disputes in IACs, the international criminal tribunals have shown a willingness to examine scrupulously if armed groups in NIACs are sufficiently organized. Still, this article argues that there is need for a nuanced assessment of the organizational level of an armed group in some specific phases of the ongoing armed conflict whose legal character switches (from an NIAC to an IAC, vice-versa, and from a NIAC to a law-enforcement model). It explores what rationales and argumentative model may be adduced to explain such varying standards for organization in different contexts.

DFB Lasers with Tilted Waveguide for Multi-Wavelength Generation

2007 ◽  
Vol 31 ◽  
pp. 36-38 ◽  
Author(s):  
Lip Fah Chong ◽  
Jing Hua Teng ◽  
Ee Leong Lim ◽  
Norman Soo Seng Ang ◽  
J.R. Dong ◽  
...  
Keyword(s):  
Single Mode ◽  
Distributed Feedback ◽  
Couple Mode ◽  
Threshold Condition ◽  
Couple Mode Theory ◽  
Gain Margin ◽  
Ridge Waveguides ◽  
Multi Wavelength ◽  
Dfb Laser ◽  
Lasing Frequency

In this paper, we present the theoretical investigation of index-coupled distributed feedback (DFB) laser with tilted single mode ridge waveguides. By tilting part of the ridge waveguide in various degrees, DFB laser with manifold effective grating periods can be realized. The structure is analyzed using couple mode theory in matrix form based on threshold analysis. Important parameters of DFB laser like resonant frequency and threshold gains are obtained by solving the eigen-equation. The results indicate not only that the lasing frequency is modulated by the waveguide titling angle, but also large Gain Margin (GM) can be achieved at the threshold condition which enhance the stable single mode operation in index-coupled DFB laser.

scholarly journals Observation of direction instability in a fiber ring laser

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Muhammad Assad Arshad ◽  
Alexander Hartung ◽  
Arni Candra Pratiwi ◽  
Matthias Jäger
Keyword(s):  
Pump Power ◽  
Ring Laser ◽  
Instability Threshold ◽  
Fiber Ring Laser ◽  
Fiber Ring ◽  
Pump Power Threshold ◽  
Power Threshold ◽  
Length Scaling

AbstractWe report on the observation of a new phenomenon occurring in a fiber ring laser. This phenomenon is about the transition from an initially bidirectional emission of a reciprocal fiber ring laser to a unidirectional emission at a certain pump power threshold. In addition, the final direction is not predefined but appears to be randomly chosen every time the threshold is exceeded. Therefore, we term this new phenomenon direction instability. Furthermore, we provide a first discussion of how the instability threshold is influenced by the length and the loss of the cavity. We show that the threshold follows a power times length scaling, indicating a nonlinear origin.

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