Eroded Species and Sticking Coefficient

For all three regimes of carbon erosion outlined above [44] the eroded species were investigated intensively. At room temperature and energies in the keV range, physical sputtering occurs with carbon atoms being eroded, predominantly. At elevated temperatures, chemical erosion increases the erosion yield 

The evaluation of the cavity deposition for the three different regimes of chemical erosion has resulted in the finding, that apart from the emission of volatile hydrocarbons at elevated temperature and physical sputtering of carbon atoms at high energies, predominantly species with sticking coefficients around 0.02 are produced. A summary of results is given in Table 9.1. 

Such species will be deposited in fusion devices in the vicinity of the location of erosion after few collisions and not travel deep into pump ducts and other remote areas. Similar conclusions are deduced from cavity collector probes introduced directly in fusion devices such as JET and ASDEX Upgrade [55,56]. 

Sticking Coeff. close to 0 0 factor 1.5 from weight loss 0 

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