Dr
Pavel Dvoลรกk
(Masaryk University)
9/27/17, 3:10โฏPM
Low-temperature plasmas
POSTER
Concentration of atomic hydrogen radicals in atmospheric-pressure dielectric barrier discharge (DBD) was measured by means of two-photon absorption laser-induced fluorescence (TALIF) and calculated by means of combination of gas flow model with zero-dimensional chemistry model. The volume DBD was ignited in a so-called atomizer (device used in analytical chemistry for detection of...
Mr
Zhiyong Zou
(Institute of Plasma Physics, Chinese Academy of Sciences)
9/27/17, 3:12โฏPM
High-temperature plasmas
POSTER
Polarimetric and interferometric measurement with high temporal, spatial resolution on EAST provides essential tools to study more than 100ย s high beta H-mode operation, optimization of High-Performance Advanced Tokamak and ITER-like scenarios. Optimization optical layout and hardware of POINT system is essential for implementing plasma density, current and vertical displacement real-time...
Mr
Junpei Itagaki
(Plasma Research Center, University of Tsukuba)
9/27/17, 3:14โฏPM
High-temperature plasmas
POSTER
Heterodyne reflectometers are used for fluctuation measurements of a high-performance mirror plasma on GAMMA 10. It is important that the offset in IQ signals is minimized to evaluate density fluctuations quantitatively when the phase and amplitude modulation components are separated. A horn antenna pair for transmitting and receiving microwaves is installed inside the vacuum chamber in the...
Mr
Weiming Li
(University of Science and Technology of China)
9/27/17, 3:16โฏPM
High-temperature plasmas
POSTER
Interferometer for plasma density measurement is sensitive to path length change and mechanical vibration introduced by optics, temperature, airflow and even sound waves. It is a particular problem for a short wavelength interferometer which will be used for burning plasmas like ITER since the phase change due to vibrations is inversely proportional to wave length. To minimize these effects...
Dr
June-Woo Juhn
(National Fusion Research Institute)
9/27/17, 3:18โฏPM
High-temperature plasmas
POSTER
Signals of vibrations are measured in different interferometers of Korea Superconducting Tokamak Advanced Research, KSTAR. The KSTAR device is equipped with three different interferometers. Millimeterwave (MMWI), far-infrared (FIRI) and two-color (TCI) whose viewing chords are all different : Horizontal, vertical and tangential way respectively. The mountings of each retro-reflector are also...
Dr
Tsuyoshi Akiyama
(National Institute for Fusion Sceience)
9/27/17, 3:20โฏPM
High-temperature plasmas
POSTER
Interferometers which measure plasma induced phase shifts are a common approach for probing line-integrated electron density. However, since changes in the beam path length caused by mechanical vibrations can often cause comparable or larger phase shifts, one of the main challenges of this measurement is reduction of the vibration contribution either through an optical solution or simply a...
Dr
Min Park
(Korea Atomic Energy Research Institute)
9/27/17, 3:22โฏPM
Low-temperature plasmas
POSTER
Hydrogen plasmas are widely used in various applications. Particularly, in the fields of nuclear fusion and accelerators, a sufficient amount of hydrogen negative ions are extracted from the plasma and accelerated to form high current negative ion beams. In order to develop plasma sources producing high density negative ions, negative ion density measurement as well as plasma characterization...
Dr
Jean-Paul Booth
(LPP-CNRS)
9/27/17, 3:24โฏPM
Low-temperature plasmas
POSTER
Electric propulsion technology (plasma thrusters) for satellite positioning and orbit change is a rapidly expanding field. Whereas most existing devices (principally Hall Effect Thrusters) use xenon gas, due to its high mass and low ionisation potential, there is growing interest in the use of Iodine[1], due to its ease of storage (solid state) and low cost, in addition to a mass and...
Mr
รbel Kรกlosi
(Charles University, Faculty of Mathematics and Physics, Department of Surface and Plasma Science)
9/27/17, 3:26โฏPM
Low-temperature plasmas
POSTER
A stationary afterglow apparatus in conjunction with a laser absorption cavity ring-down spectrometer has been employed to observe absorption lines in the P- and R-branches of the $2v_1$ vibrational band of the $\mathrm{N_2H^+}$ molecular ion as a part of an ongoing experimental campaign whose goal is to study the electron-ion recombination of $\mathrm{N_2H^+}$ in afterglow plasmas. The probed...
Mr
Jongin Wang
(NUPLEX, Seoul National University)
9/27/17, 3:28โฏPM
Instrumentation development
POSTER
A single channel of 94 GHz heterodyne interferometer system for measurement of the electron density [1] was successfully developed for Versatile Experiment Spherical Torus (VEST) at Seoul National University. The interferometer system has been upgraded to a multi-chord heterodyne interferometer system for the profile of electron density. The Gaussian probe beam from a horn antenna is expanded...
Dr
Wenzhe Mao
(University of Science and Technology of China)
9/27/17, 3:30โฏPM
High-temperature plasmas
POSTER
A one chord microwave interferometer has been applied to measure forward scattering from electron density fluctuations on KTX reversed field pinch. Two terahertz microwave souces are used to form a heterodyne interferometer system. Frequency of the diagnostic beam is about 650 GHz and the power of each source is about 2 mw. The diagnostic beam goes vertically through the center of the plasma,...
Dr
Yuan Yao
(Institute of Plasma Physics, Chinese Academy of Sciences)
9/27/17, 3:32โฏPM
High-temperature plasmas
POSTER
The far-infrared laser-based HCN interferometer and POlarimeter/INTerferometer (POINT) system are important diagnostics for plasma density measurement on EAST tokamak. Both HCN and POINT provide high spatial and temporal resolution of electron density measurement and used for plasma density feedback control. The density is calculated by measuring the real-time phase difference between the...
Dr
Leo Matsuoka
(Hiroshima university)
9/27/17, 3:34โฏPM
Low-temperature plasmas
POSTER
The narrow Lorentzian spectrum is obtained by using saturated absorption spectroscopy in the atomic ensemble without strong collisions. In the plasma with strong collisions, on the other hand, the saturated absorption spectrum is partially or fully broadened to the Gaussian shape whose width is the same order as the Doppler broadening. In the argon arcjet plasma, as a plasma which exhibits...
Mr
Feng Chu
(University of Iowa)
9/27/17, 3:36โฏPM
Low-temperature plasmas
POSTER
Extensive information can be obtained on wave-particle interactions and wave fields by direct measurement of perturbed ion distribution functions using laser-induced fluorescence (LIF). For practical purposes, LIF is frequently performed on metastable states that are produced from neutral gas particles and ions in other electronic states. If the laser intensity is increased to obtain a better...
Martina Mrkvickova
(Department of Physical Electronics, Masaryk University, Brno, Czech republic)
9/27/17, 3:38โฏPM
Low-temperature plasmas
POSTER
The presented study reports on the technique of extraction of the collisional quenching coefficients of the N2(B$^3\Pi_g$) vibrational levels by nitrogen molecule.
The quenching was examined by the laser-induced fluorescence technique in the monofillamentary volume DBD streamer discharge ignited in pure nitrogen at low pressures [1, 2]. The discharge was powered by periodic high-voltage...
Dr
Xiang Zhu
(Institute of Plasma Physics, Chinese Academic of Sciences)
9/27/17, 3:40โฏPM
High-temperature plasmas
POSTER
A novel method has been developed to improve the accuracy of safety factor (q) profile by combining the polarimeter/interferometer (POINT) measurements with the external magnetic measurements on the EAST tokamak. The POINT system, measuring the accurate line-integrated electron density and Faraday rotation angle, provides the magnetic field information inside the plasma. By adding these data...
Dr
Ryuya Ikezoe
(Plasma Research Center, University of Tsukuba)
9/27/17, 3:42โฏPM
High-temperature plasmas
POSTER
Slow Alfvรฉn waves in ion cyclotron range of frequencies (ICRF) are a powerful tool to heat ions confined in a mirror field. In spite of its efficient heating effect that has been attained in the central cell of GAMMA 10, there are still unknown characteristics concerning boundary condition, transient variation of heating effect, exact picture of cyclotron damping, and so on. What we need to...
Prof.
Fred Skiff
(University of Iowa, Dept. Physics and Astronomy)
9/27/17, 3:44โฏPM
Low-temperature plasmas
POSTER
We show how cross-corrlelation of the fluctuations in LIF between two laser beams exciting optically isolated metastable lines can be used to identify and separate the power spectra of plasma electrostatic modes while using only a single measurement location. A matrix of measurements of:
C(v,v',t')= {df(x,v,t)df(x,v',t-t')}t,
Fourier transformed over the time delay t', produces a...
Dr
Milan Simek
(Institute of Plasma Physics of the CAS, Czech Republic)
9/27/17, 3:46โฏPM
Low-temperature plasmas
POSTER
We report on the N$_2$(A$^3\Sigma_u^+$, $\nu$) vibrational kinetics in nitrogen-oxygen mixtures revealed by LIF technique under DBD streamer discharge conditions at low pressures. Triggered single streamer events were produced in pure N$_2$ and N$_2$-O$_2$ mixtures employing volume DBD geometry at a pressure of 50 Torr. The discharge concept is based on a pair of metallic electrodes embedded...
Dr
Cyril Drag
(Laboratoire Aimรฉ-Cotton)
9/27/17, 3:48โฏPM
Instrumentation development
POSTER
Neutral beam injection, for plasma heating, will supposedly be achieved, in ITER, by collisional detachment of a pre-accelerated D${^-}$ beam. Collisional detachment however makes the presence of a D2-filled neutralisation chamber necessary, on the beam line. This has severe drawbacks, due to collisions with the injected gas up- and downstream from the collision chamber and the impossibility...
