Transport and Deposition of Hydrocarbons in the Plasma Generator PSI-2

Naujoks, D.; Bohmeyer, W.; Маркин, А. А.; Arkhipov, Ievgen I.; Carl, Peter; Koch, B.; Reiner, H.‐D.; Schröder, Daniel; Fußmann, G.

doi:10.1238/physica.topical.111a00080

Cited by 8 publications

(10 citation statements)

References 20 publications

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“…Erosion of a-C:D layers by atomic hydrogen was also observed at the plasma generator PSI-2 [26]. It was concluded from these experiments, that during simultaneous bombardment with atomic hydrogen and hydrocarbon radicals the flux of atomic hydrogen determines whether net deposition or net erosion is observed [25,27].…”

Section: Discussionmentioning

confidence: 87%

Further insight into the mechanism of hydrocarbon layer formation below the divertor of ASDEX Upgrade

Mayer

Rohde

2006

Nucl. Fusion

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Abstract. The surface loss probability of hydrocarbon radicals was measured below the roof baffle of the ASDEX Upgrade divertor using the cavity technique. Hydrocarbon layers are mainly formed by sticking of hydrocarbon radicals with high surface loss probabilities of about 0.2 and close to unity. In addition to sticking re-erosion by atomic hydrogen plays an important role in layer formation. The temperature dependence of layer formation was measured with heated and cooled long term samples from 77 K to 475 K. The layer growth rate is larger by a factor of about 40 at 77 K compared to room temperature, while it is lower by a factor of about 70 at 475 K than at room temperature due to enhanced re-erosion. Implications of the results for predictions of tritium retention in future fusion devices and hydrocarbon layer formation on mirror surfaces are discussed.

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Section: Discussionmentioning

confidence: 87%

Further insight into the mechanism of hydrocarbon layer formation below the divertor of ASDEX Upgrade

Mayer

Rohde

2006

Nucl. Fusion

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“…In general, a strong temperature dependence of the deposition is observed, which is due to the strong temperature dependence of the re-erosion of deposited layers by atomic hydrogen, as demonstrated in laboratory experiments [337]. This has important implications for the recovery of the tritium retained on deposited hydrocarbon films.…”

Section: Location and Properties Of Carbon Film Depositsmentioning

confidence: 89%

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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“…For local impurity modelling the leading European code is ERO [8,9] -a 3D Monte Carlo impurity transport code that has been applied to several limiter and divertor tokamaks as well as linear plasma experiments, see, e.g., [10][11][12][13][14][15] . ERO depends crucially on high-quality data for PWI as well as for dissociation, ionization and emission data for impurities in the plasma.…”

Section: Introductionmentioning

confidence: 99%