Journals

Showing 1 - 10 of 93 Journals Results
2021
UKAEA-CCFE-PR(21)02

In quiescent H-mode (QH-mode) regime, edge harmonic oscillations (EHOs) are believed to provide necessary radial transport to prevent occurrence of large edge localized modes. A systematic modeling study is performed here on the low-n EHOs in a DIII-D QH-mode plasma [Chen et al. 2016 Nucl. Fusion 56 076011], by utilizing the MARS-Q code [Liu et a…

Preprint
2020
UKAEA-CCFE-PR(20)139

The HL-2A tokamak has a very closed divertor geometry, and a new infrared camera has been installed for high resolution studies of edge-localized mode (ELM) heat load onto the outer divertor targets. The characteristics of power deposition patterns on the lower outer divertor target plates during ELMs are systematically analyzed with the infrared t…

Preprint
2020
UKAEA-CCFE-PR(20)121

Effects of parallel and poloidal flows, as well as the flow shear, on the resistive wall mode (RWM) instability have been numerically investigated in toroidally rotating plasmas, utilizing a recently updated version of the MARS-F code (Liu Y Q et al 2000 Phys. Plasmas 7 3681). A significant difference between these flows i…

Preprint Published
2020
UKAEA-CCFE-PR(20)120

A Doppler coherence imaging spectroscopy diagnostic has been developed on the HL- 2A tokamak for scrape-off-layer impurity plasma flow measurements. Two- dimensional imaging of line-averaged C2+ flow in the high-field-…

Preprint Published
2020
UKAEA-CCFE-PR(20)102

Modification of the external tearing index, Δ’ext , by magnetic feedback is analytically investigated, for the purpose of controlling the resistive plasma resistive wall mode (RP-RWM). The matching method is pursued, by deriving expressions for the close-loop Δ’ext and by linking it to the counterpart from the inner layer. Various…

Preprint Published
2020
UKAEA-CCFE-PR(20)05

Resistive plasma response to the n = 1 (n is the toroidal mode number) RMP field is systematically investigated for a high-beta hybrid discharge on ASDEX Upgrade. Both linear and quasi-linear response are modelled using the MARS-F and MARS-Q codes, respectively. Linear response computations show a large internal kink response when the plasma centr…

Preprint Purchase
The published version of this paper is currently under embargo and will be available on 28/07/2021
2020
UKAEA-CCFE-PR(19)18

Abstract. A numerical survey of the plasma response in ASDEX Upgrade ELM control experiments is conducted, to clarify the role of triangularity in the suppression mechanism. The pedestal pressure increases with triangularity consistent with previous work [2], which modestly boosts the peeling response. However, the peeling response decreases wit…

Preprint Published
2019
UKAEA-CCFE-PR(19)71

Deformation mechanisms of high entropy alloys (HEAs) at cryogenic temperatures have attracted extensive research interest. We used in situ neutron diffraction to study the tensile behavior of a face-centered-cubic HEA at 77 and 15 K and compared its stacking fault energy (SFE) at ambient and cryogenic temperatures. The SFE dropped from 28…

Preprint Purchase
2018
UKAEA-CCFE-PR(18)61

Effects of toroidal plasma flow, magnetic drift kinetic damping as well as feedback control, on the resistive wall mode instability in HL-2M tokamak are numerically investigated, using the linear stability codes MARS-F/K (Liu Y Q et al 2000 Phys. Plasmas 7 3681, Liu Y Q et al 2008 Phys. Plasmas 15…

Preprint Published
2018
UKAEA-CCFE-PR(18)56

The deformation responses at 77 and 293 K of a FeCoNiCr high-entropy alloy, produced by a powder metallurgy route, are investigated using in situ neutron diffraction and correlative transmission electron microscopy. The strength and ductility of the alloy are significant improved at cryogenic temperatures. The true ultimate tensile strengt…

Preprint Published