scholarly journals First experiments on ICRF discharge generation by a W7-X-like antenna in the Uragan-2M stellarator

2020 ◽  
Vol 86 (5) ◽  
Author(s):  
V. E. Moiseenko ◽  
Yu. V. Kovtun ◽  
T. Wauters ◽  
A. Goriaev ◽  
A. I. Lyssoivan ◽  
...  
Keyword(s):  
Experimental Study ◽  
Hydrogen Production ◽  
Cyclotron Frequency ◽  
Vacuum Vessel ◽  
Plasma Production ◽  
Plasma Production And Heating ◽  
Ion Generation ◽  
Target Plasma ◽  
Fast Ion ◽  
Made In

In support of the ICRF experiments planned on the Wendelstein 7-X (W7-X) stellarator, i.e. fast ion generation, wall conditioning, target plasma production and heating, a first experimental study on plasma production has been made in the Uragan-2M (U-2M) stellarator using W7-X-like two-strap antenna. In all the experiments, antenna monopole phasing was used. The W7-X-like antenna operation with launched radiofrequency power of ~100 kW have been performed in helium (p = (4–14) × 10−2 Pa) with the vacuum vessel walls pre-loaded with hydrogen. Production of plasma with a density higher than 1012 cm−3 was observed near the first harmonic of the hydrogen cyclotron frequency. Operation at first hydrogen harmonic is feasible in W7-X future ICRF experiments.

scholarly journals Novel internal measurements of ion cyclotron frequency range fast-ion driven modes

2021 ◽  
Author(s):  
Neal A Crocker ◽  
Shawn X Tang ◽  
Kathreen E Thome ◽  
Jeff Lestz ◽  
Elena Belova ◽  
...  
Keyword(s):  
Cyclotron Frequency ◽  
Harmonic Wave ◽  
Wave Number ◽  
Frequency Range ◽  
High Wave Number ◽  
Minor Radius ◽  
Ion Cyclotron ◽  
Cyclotron Emission ◽  
Edge Localized Modes ◽  
Fast Ion

Abstract Novel internal measurements and analysis of ion cyclotron frequency range fast-ion driven modes in DIII-D are presented. Observations, including internal density fluctuation (ñ) measurements obtained via Doppler Backscattering, are presented for modes at low harmonics of the ion cyclotron frequency localized in the edge. The measurements indicate that these waves, identified as coherent Ion Cyclotron Emission (ICE), have high wave number, _⊥ρ_fast ≳ 1, consistent with the cyclotron harmonic wave branch of the magnetoacoustic cyclotron instability (MCI), or electrostatic instability mechanisms. Measurements show extended spatial structure (at least ~ 1/6 the minor radius). These edge ICE modes undergo amplitude modulation correlated with edge localized modes (ELM) that is qualitatively consistent with expectations for ELM-induced fast-ion transport.

scholarly journals An Experimental Study on the Strengthening of RC Frames with Soft Storey Irregularities with Different Types of Steel Diagonals

2018 ◽  
Author(s):  
Murat Ozturk ◽  
Tevfik F. Ogutcu
Keyword(s):  
Experimental Study ◽  
Reference Frame ◽  
Behavioral Differences ◽  
Infill Wall ◽  
Loss Of Life ◽  
Soft Storey ◽  
Rc Frames ◽  
Load Carrying ◽  
Made In ◽  
Strengthening Method

When the loss of life and property is considered, it is clear that special precautions must be taken against the earthquakes among the natural disasters. Post-earthquake observations, especially those made in the developing countries, reveal that there are many reasons for the damage and loss of life, not just one. The formation of soft storey irregularity is one of the most important factors among them. In this study, it is aimed to propose an alternative strengthening method to eliminate the adverse effects of the formation of a soft storey irregularity. Four identical frames with two stories and single span were constructed and tested under reverse cyclic loading which simulates the earthquake. The first frame among them was prepared by bonding bricks as an infill wall on two stories and it was considered to be the reference frame. In the 2nd frame, the formation of soft storey irregularity was facilitated by removing the infill wall on the lower story and the behavioral differences were examined. The remaining two frames were strengthened by using steel elements in two different diagonal shapes on the lower story. As a result, the experimental study showed that the strengthening with steel diagonal elements increased the lateral load-carrying capacity of the frame with soft storey behavior by 250% and the energy dissipation by 120% and also provided better results than the reference frame.

scholarly journals Experimental Study for HIx Concentration by Electro-Electrodialysis (EED) Cells in the Water Splitting Sulfur-Iodine Thermochemical Cycle

2019 ◽  
Vol 3 (2) ◽  
pp. 50 ◽  
Author(s):  
Giampaolo Caputo ◽  
Irena Balog ◽  
Alberto Giaconia ◽  
Salvatore Sau ◽  
Alfonso Pozio
Keyword(s):  
Experimental Study ◽  
Hydrogen Production ◽  
Water Splitting ◽  
Transport Number ◽  
Hydriodic Acid ◽  
Thermochemical Cycle ◽  
Slow Increase ◽  
Electro Osmosis ◽  
A Current ◽  
Splitting Process

The efficiency of HI concentration/separation from a HIx solution, (mixture of HI/H2O/I2) represents a crucial factor in the sulfur-iodine thermochemical water splitting process for hydrogen production. In this paper, an experimental study on HI cathodic concentration in HIx solution using stacked electro-electrodialysis (EED) cells was carried out under the conditions of 1 atm and at three different temperature (25, 55 and 85 °C) and using a current density of 0.10 A/cm2. Results showed that an increase in HI concentration can be obtained under certain conditions. The apparent transport number (t+) in all the experiments was very close to 1, and the electro-osmosis coefficient (β) changed in a range of 1.08–1.16. The tests showed a detectable, though slow, increase in both the anodic iodine and cathodic hydriodic acid concentrations.

Edge plasma potential and associated ion fluxes to the surface during ICRF plasma production and heating in the Uragan-3 Torsatron

1990 ◽  
Vol 12 (1-2) ◽  
pp. 171-178 ◽  
Author(s):  
V.V. Chechkin ◽  
L.I. Grigor'eva ◽  
N.I. Nazarov ◽  
O.S. Pavlichenko ◽  
G.N. Polyakova ◽  
...  
Keyword(s):  
Plasma Potential ◽  
Ion Fluxes ◽  
Edge Plasma ◽  
Plasma Production ◽  
Plasma Production And Heating
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