摘要：
Fast wave in the ion-cyclotron resonance frequency (ICRF) range is a promising candidate for non-inductive current drive (CD), which is essential for long pulse and high performance operation of tokamaks. A numerical study on the ICRF fast wave current drive (FWCD) and mode-conversion current drive (MCCD) in the Experimental Advanced Superconducting Tokamak (EAST) is carried out by means of the coupled full wave and Ehst-Karney parameterization methods. The results show that FWCD efficiency is notable in two frequency regimes, i.e., f ≥ 85 MHz and f = 50–65 MHz, where ion cyclotron absorption is effectively avoided, and the maximum on-axis driven current per unit power can reach 120 kA/MW. The sensitivity of the CD efficiency to the minority ion concentration is confirmed, owing to fast wave mode conversion, and the peak MCCD efficiency is reached for 22% minority-ion concentration. The effects of the wave-launch position and the toroidal wavenumber on the efficiency of current drive are also investigated.
摘要：
Collisionless damping of the geodesic acoustic mode due to electron dynamics in rotating tokamak plasmas is investigated. A dispersion relation of the geodesic acoustic mode with a non-adiabatic electron response in a rotating tokamak is derived and solved both analytically and numerically. It is found that the collisionless damping of the geodesic acoustic mode, due to electron dynamics, significantly increases with the increasing toroidal rotation, especially in the large safety factor regime. The rotation-induced frequency up-shift of the geodesic acoustic mode increases the resonant velocity, which enables a larger number of electrons to resonate with the geodesic acoustic mode. The significant increase of the number of the resonant electrons significantly enhances the collisionless damping of the geodesic acoustic mode. The result indicates that in rotating tokamak plasmas a more complete picture of the geodesic acoustic mode should include the electron dynamics.
摘要：
With the dispersion relation derived for the geodesic acoustic mode in toroidally rotating tokamak plasmas using the fluid model, the effect of the toroidal rotation on the collisional viscous damping of the geodesic acoustic mode is investigated. It is found that the collisional viscous damping of the geodesic acoustic mode has weak increase with respect to the toroidal Mach number.
摘要：
The collisional damping of the geodesic acoustic mode (GAM) is analytically investigated in toroidally rotating tokamaks by using the gyrokinetic equation. It is found that the toroidal rotation could decrease the collisional damping of the GAM in the small safety factor region and increase the collisional damping of the GAM in the large safety factor region at low ion collision rate; while at high ion collision rate, the toroidal rotation will increase the collisional damping of the GAM with arbitrary safety factor. Furthermore, the change quantity of collisional damping rate of the GAM due to the toroidal rotation at high collision rate is larger than that at low collision rate.
作者机构：
[Chen, You; Gong, Xueyu; Yu, Jun] Univ South China, Sch Math & Phys, Hengyang 421001, Hunan, Peoples R China.;[Gong, Xueyu] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Hunan, Peoples R China.
通讯机构：
[Yu, Jun] U;Univ South China, Sch Math & Phys, Hengyang 421001, Hunan, Peoples R China.
关键词：
tokamak plasma;zonal flow;turbulence
摘要：
With the nonlinear dispersion relation derived, excitation of low frequency zonal flow by drift waves is examined in tokamak plasmas with toroidal rotation. It is shown that the growth rate of the low frequency zonal flow is decreased by the frequency shift of the geodesic acoustic mode and is increased by the additional nonlinear terms with toroidal rotation velocity. If the amplitude of the pump drift wave is greater than the threshold value, which is the function of the Mach number of the toroidal rotation, the toroidal rotation increases the nonlinear growth rate, otherwise, it decreases the nonlinear growth rate. There is always a finite nonlinear growth rate of the low frequency zonal flow if only there is a finite amplitude of the pump wave in tokamak plasmas with a finite velocity of the toroidal rotation.
关键词：
Laser;Microwave-Photonic link (MPL);Phase noise;Relative intensity noise (RIN)
摘要：
A new method for measuring the relative intensity noise (RIN) of a laser is proposed and verified by experiment in this paper. As an important module of microwave-photonic link (MPL). the RIN of a laser has contribution to systematic noises of MPL in the type of the intensity modulation and direct detection (IM-DD), so the phase noise of transmitted carrier would increase. This physical phenomenon is used to measure RIN of a laser and this method avoids the influence of near-dc noise and is unrestricted by the power of the laser compared with previous methods.
