Enhancement of edge turbulence concomitant with ELM suppression during boron powder injection in EAST

2021 ◽  
Vol 28 (8) ◽  
pp. 082512
Author(s):  
Z. Sun ◽  
R. Maingi ◽  
A. Diallo ◽  
W. Xu ◽  
Y. Z. Qian ◽  
...  
Keyword(s):  
Powder Injection ◽  
Boron Powder

scholarly journals Observations of wall conditioning by means of boron powder injection in DIII-D H-mode plasmas

2020 ◽  
Vol 60 (12) ◽  
pp. 126010 ◽  
Author(s):  
A. Bortolon ◽  
R. Maingi ◽  
A. Nagy ◽  
J. Ren ◽  
J.D. Duran ◽  
...  
Keyword(s):  
Powder Injection ◽  
Boron Powder

scholarly journals Observation of a reduced-turbulence regime with boron powder injection in a stellarator

2022 ◽  
Author(s):  
F. Nespoli ◽  
S. Masuzaki ◽  
K. Tanaka ◽  
N. Ashikawa ◽  
M. Shoji ◽  
...  
Keyword(s):  
Turbulent Transport ◽  
Powder Injection ◽  
Fusion Reactions ◽  
Plasma Confinement ◽  
Boron Powder ◽  
Turbulent Fluctuations ◽  
Neutral Beams ◽  
Turbulence Regime ◽  
Nuclear Fusion Reactions ◽  
The Magnetic Field

AbstractIn state-of-the-art stellarators, turbulence is a major cause of the degradation of plasma confinement. To maximize confinement, which eventually determines the amount of nuclear fusion reactions, turbulent transport needs to be reduced. Here we report the observation of a confinement regime in a stellarator plasma that is characterized by increased confinement and reduced turbulent fluctuations. The transition to this regime is driven by the injection of submillimetric boron powder grains into the plasma. With the line-averaged electron density being kept constant, we observe a substantial increase of stored energy and electron and ion temperatures. At the same time, the amplitude of the plasma turbulent fluctuations is halved. While lower frequency fluctuations are damped, higher frequency modes in the range between 100 and 200 kHz are excited. We have observed this regime for different heating schemes, namely with both electron and ion cyclotron resonant radio frequencies and neutral beams, for both directions of the magnetic field and both hydrogen and deuterium plasmas.

scholarly journals Observation of a novel reduced-turbulence regime with boron powder injection in a stellarator

2021 ◽  
Author(s):  
Federico Nespoli ◽  
Suguru Masuzaki ◽  
Kenji Tanaka ◽  
Naoko Ashikawa ◽  
Mamoru Shoji ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Radio Frequency ◽  
Powder Injection ◽  
Stored Energy ◽  
Ion Temperature ◽  
Boron Powder ◽  
Turbulent Fluctuations ◽  
Neutral Beams ◽  
Turbulence Regime ◽  
The Magnetic Field

Abstract We report the first observation of a novel confinement regime in a stellarator plasma, characterized by increased confinement and reduced turbulent fluctuations. The transition to this new regime is driven by the injection of sub-millimetric boron powder grains into the plasma. With the line averaged electron density being kept constant, substantial increase of stored energy, electron and ion temperature have been observed. At the same time, the amplitude of the plasma turbulent fluctuations is halved. While lower frequency fluctuations are damped, higher frequency modes in the range 100 ≤ f [kHz] ≤ 200 are excited. The access to this regime has been observed for different heating schemes, namely with both electron and ion cyclotron resonant radio frequency, and neutral beams, for both directions of the magnetic field, and for both hydrogen and deuterium plasmas.

Specific volume and features of compressibility during the molding of powder-polymer mixtures with wax-polypropylene binder

2019 ◽  
pp. 25-33
Author(s):  
Alexander Muranov ◽  
Alexey Semenov ◽  
Anatoly Kutsbakh ◽  
Boris Semenov
Keyword(s):  
Phase Transition ◽  
Comparative Analysis ◽  
Powder Metallurgy ◽  
Injection Molding ◽  
Polymer Binder ◽  
Polymer Mixture ◽  
Powder Injection ◽  
Polymer Mixtures ◽  
Pvt Data ◽  
Mathematical Processing

The article discusses one of the modern areas of powder metallurgy – the technology of manufacturing shaped parts by the powder injection molding (PIM). For the powder-polymer mixture (feedstock) with a wax-polypropylene binder of the solvent-thermal type of removal by isobaric volume dilatometry, the dependence of PVT state parameters was studied. For each component of the polymer binder, the dependence of pressure on the temperature of phase transition was obtained. As a result of mathematical processing and analysis of PVT data for the feedstock of the studied type, a technological window of parameters has been determined that allows injection molding of «green parts» with minimal volume shrinkage. The results of a comparative analysis of the compaction of feedstock with a polymer binder catalytic and solution-thermal type of removal are presented.

Effect of Additives on the Characteristics of Amorphous Nano Boron Powder Fabricated by Self-Propagating High Temperature Synthesis

2015 ◽  
Vol 25 (12) ◽  
pp. 659-665
Author(s):  
Sin Hyong Joo ◽  
Hayk H. Nersisyan ◽  
Tae Hyuk Lee ◽  
Young Hee Cho ◽  
Hong Moule Kim ◽  
...  
Keyword(s):  
High Temperature ◽  
Temperature Synthesis ◽  
Boron Powder ◽  
Effect Of Additives ◽  
High Temperature Synthesis
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