Zun Zhang added an answer:How should the Langmuir probe be set; parallel or perpendicular with the plasma flow direction in very fast flowing plasmas (30km/s)?
The plume plasmas from electric thrusters, for example ion thrusters, are always with a high velocity usually several tens of kilometers per second (supersonic flow).
For Langmuir probe diagnostics, it is normally used in the stationary plasmas. When it is applied in the fast moving plasmas, the cylindrical probe tip should be set parallel or perpendicular with the plasma flows? and which is better? why?
I have read several papers and learned that some set parallel, and others set perpendicular. So I feel confused.
@ Jinwen Cao
I have downloaded your referred paper by the name from some website, but it just has the abstract section not the full paper. Would you mind to send me a copy to my email: email@example.com if you got one? Much thanks~Following
Robert Elliman added an answer:Optimum angle (for maximum sputter yield) of incidence from surface normal in ion beam sputtering?I want to know the physical significance of variation sputtering yield at different angle of incidence (w.r.t. ion beam) and also the with fluence and energy of the ion beam.As noted above, the sputter yield increases with the angle of ion incidence due to the increase in energy near-surface energy deposition and decreases at the large angle of incidence due to ion reflection.
The SRIM code does not take account of the changing composition of the sample during ion bombardment, instead it assumes that each ion enters an unperturbed sample. If you wish to model composition changes (i.e. preferential sputtering or the accumulation of the implanted species) you would need to run a code such as TriDyn. (see: http://www.hzdr.de/db/Cms?pOid=21578&pNid=0). SIMTRA is more suited to modelling magnetron sputter deposition rather than sputtering due to a directed beam of monoenergetic ions.Following
Yuriy Kudriavtsev added an answer:Can anyone suggest literature for in depth understanding of sputtering yield?I am working on measurement of differential and total sputtering yield measurement of ceramic material using quartz crystal microbalance (by using ion source). At present I am more inclined towards the fundamental and the theoretical aspects of sputtering yield, so it may be more fruitful in my experimental work.Sputtering by particle bombardment, I-III, edited by R. Behrisch
in "Topics in Applied Physics". There are three volumes:
I- Sputtering of single-element targets. 1981
II- Sputtering of alloy and compounds. 1983 (Edt. H.H.Andersen)
III- Characteristics of Sputtered particles. 1991
A new version of these books was published in 2007 (Edt. Behrisch and Eckstein)Following
About ion thruster
Using an ION beam generated on earth to supply electrical energy above the atmosphere for launch propulsion of super heavy weight, high-energy SpaceShips.