Measurement of Ion Flow Velocity Field Associated with Plasma Hole Using Laser Induced Fluorescence Spectroscopy
نویسندگان
چکیده
“Plasma hole” is a singular vortex spontaneously formed in an electron cyclotron resonance plasma. So far the ion flow velocity field associated with the plasma hole has been measured with a directional Langmuir probe (DLP). Here we present the first result of measuring azimuthal and radial flow velocity profiles of the plasma hole in an argon plasma using a laser induced fluorescence (LIF) Doppler spectroscopy, which demonstrates the effectiveness of LIF spectroscopy for absolute flow velocity measurement of the plasma hole. The azimuthal flow was found to be nearsonic rotation, the Mach number of which was approximately 0.65, which agreed with the previous DLP measurements. The radial flow was found to be outward and the velocity was considerably small, which is different from the previous DLP measurements of the plasma hole in a helium plasma. The possible causes of this discrepancy are discussed.
منابع مشابه
Measurement and simulation of laser-induced fluorescence from nonequilibrium ultracold neutral plasmas
We report measurements and simulations of laser-induced fluorescence in ultracold neutral plasmas. We focus on the earliest times, when the plasma equilibrium is evolving and before the plasma expands. In the simulation, the ions interact via the Yukawa potential in a small cell with wrapped boundary conditions. We solve the optical Bloch equation for each ion in the simulation as a function of...
متن کاملSimultaneous measurement of water flow velocity with fluorescent and speckle imaging technique
The average velocity of water flow has been simultaneously measured with fluorescent and speckle imaging methods. The measured velocities with two methods are in good agreement with each other and it confirms that the speckle imaging method can be used as a confident method to measure the velocity of water flow in a dry leaf. Also the velocity of water flow through thick and thin xylems of a le...
متن کاملMeasurement of neutral flow velocity in an ECR plasma using tunable diode laser LIF spectroscopy combined with saturated absorption spectroscopy
The radial flow of neutral particles in an electron-cyclotron-resonance (ECR) argon plasma has been measured by using a newly developed high resolution laser induced fluorescence (LIF) measurement system. The flow velocity is determined by the Doppler shift of the LIF spectrum. A very high accuracy calibration of an excitation laser has been achieved by installing a saturated absorption spectro...
متن کاملA new pure ion plasma device with laser induced fluorescence diagnostic
We describe a new apparatus for magnetic confinement of a pure ion plasma, with laser diagnostics to measure test particle transport across the magnetic field. In addition to the axisymmetric trapping potential, rotating electrostatic wall perturbation is used to counteract the plasma loss processes, giving steady-state ion confinement for weeks. Electronic spin polarization of the ion ground s...
متن کاملLaser induced fluorescence measurements of axial velocity, velocity shear, and parallel ion temperature profiles during the route to plasma turbulence in a linear magnetized plasma device.
We report experimental measurements of the axial plasma flow and the parallel ion temperature in a magnetized linear plasma device. We used laser induced fluorescence to measure Doppler resolved ion velocity distribution functions in argon plasma to obtain spatially resolved axial velocities and parallel ion temperatures. We also show changes in the parallel velocity profiles during the transit...
متن کامل