Molecular dynamics calculation of carbon/hydrocarbon reflection coefficients on a hydrogenated graphite surface

Alman, D. A.; Ruzic, D. N.

doi:10.1016/s0022-3115(02)01428-9

Cited by 54 publications

(47 citation statements)

References 12 publications

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“…from [435,436]. Redeposition and sticking of eroded species is computed using assumptions for the hydrocarbon radicals (such as 1 or 0) or from MolDyn calculations [437] and TRIM data for ions and atoms [438,439]. The resulting modelled tritium co-deposition is shown in Fig.…”

Section: Fuel Retention Mechanisms In Present Devices and Implicationmentioning

confidence: 99%

Chapter 4: Power and particle control

Loarte¹,

et al. 2007

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Abstract.Progress, since the ITER Physics Basis publication, in understanding the processes that will determine the properties of the plasma edge and its interaction with material elements in ITER is described. Experimental areas where significant progress has taken place are : energy transport in the SOL in particular of the anomalous transport scaling, particle transport in the SOL that plays a major role in the interaction of diverted plasmas with the main chamber material elements, ELM energy deposition on material elements and the transport mechanism for the ELM energy from the main plasma to the plasma facing components, the physics of plasma detachment and neutral dynamics including the edge density profile structure and the control of plasma particle content and He removal, the erosion of low and high Z materials in fusion devices, their transport to the core plasma and their migration at the plasma edge including the formation of mixed materials, the processes determining the size and location of the retention of tritium in fusion devices and methods to remove it and the processes determining the efficiency of the various fuelling methods as well as their development towards the ITER requirements. This experimental progress has been accompanied by the development of modelling tools for the physical processes at the edge plasma and plasma-materials interaction and the further validation of these models by comparing their predictions with the new experimental results. Progress in the modelling development and validation has been mostly concentrated in the following areas : refinement of the predictions for ITER with plasma edge modelling codes by inclusion of detailed geometrical features of the divertor and the introduction of physical effects, which can play a 2 major role in determining the divertor parameters at the divertor for ITER conditions such as hydrogen radiation transport and neutral-neutral collisions, modelling of the ion orbits at the plasma edge, which can play a role in determining power deposition at the divertor target, models for plasma-materials and plasma dynamics interaction during ELMs and disruptions, models for the transport of impurities at the plasma edge to describe the core contamination by impurities and the migration of eroded materials at the edge plasma and its associated tritium retention and models for the turbulent processes that determine the anomalous transport of energy and particles across the SOL. The implications for the expected performance of the reference regimes in ITER, the operation of the ITER device and the lifetime of the plasma facing materials are discussed. Introduction.This chapter outlines the significant progress achieved since the ITER Physics Basis in understanding basic scrape-off layer (SOL) and divertor processes in a tokamak. The interaction of plasma with first-wall surfaces will have considerable impact on the performance of fusion plasmas, the lifetime of plasma facing components, and the retention of tritium in next step Burning Plasma E...

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Section: Fuel Retention Mechanisms In Present Devices and Implicationmentioning

confidence: 99%

Chapter 4: Power and particle control

Loarte¹,

et al. 2007

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“…When a particle comes to the wall surface, whether it sticks or reflects is determined by its reflection coefficient, which is different for different species and incident energies. These reflection coefficients have been calculated with different H/C ratios using the MolDyn and HCParcas molecular dynamics codes [31][32][33], and the reflection coefficients taken from the MolDyn code have been applied in our simulation (the H/C ratio and impact angle used in MolDyn code are 0.4 and 45 • , respectively). Fig.…”

Section: Simulation Modelsmentioning

confidence: 99%

Investigations of the origins of deposited carbon species in gaps between divertor tiles using a kinetic code system

Dai

Sang

Liu

et al. 2012

Fusion Engineering and Design

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“…When a neutral particle comes to the wall surface, whether it sticks or reflects is determined by its energy-and species-dependent reflection coefficient. The energy-and species-dependent reflection coefficients for CH 4 and its reactive fragments have been calculated with different H/C ratios using the MolDyn and HCParcas molecular dynamics codes [21][22][23], and the reflection coefficients taken from the results of the MolDyn code have been applied in our simulation.…”

Section: Simulation Modelsmentioning

confidence: 99%

Modelling of Carbon Erosion and Transport at Divertor Target Plate Using a Suite of Codes

Dai

Sun

Sang

et al. 2011

Contrib. Plasma Phys.

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To investigate carbon-based material erosion and ensuing eroded carbon species density distribution, a ParticleIn-Cell Monte Carlo collision code plus a plasma-surface interaction code were combined with a Monte Carlo impurity transport code ITCD. It is found that a "density hill" forms at a distance of 3-4 mm from divertor target plate under certain circumstances: high plasma temperature, small incident angle and strength of the magnetic field. By means of the study with the combined code on several scenarios with different plasma temperatures, the incident angles and strengths of the magnetic field, the simulation results reveal that they have a significant influence on the chemical erosion of carbon-based material and the spatial distribution of eroded carbon species density above divertor target plate: the eroded carbon species density is smaller at a lower plasma temperature; the scenario with smaller incident angle and greater strength of the magnetic field can reduce the chemical erosion of carbon-based material and the eroded carbon species density above divertor target plate evidently.

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Molecular dynamics calculation of carbon/hydrocarbon reflection coefficients on a hydrogenated graphite surface

Cited by 54 publications

References 12 publications

Chapter 4: Power and particle control

Chapter 4: Power and particle control

Investigations of the origins of deposited carbon species in gaps between divertor tiles using a kinetic code system

Modelling of Carbon Erosion and Transport at Divertor Target Plate Using a Suite of Codes

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