diode laser-induced fluorescence (lif)measurements of metastable argon ions in a magnetized...
TRANSCRIPT
Diode laser-induced fluorescence (LIF)measurements of metastable argon ions in a magnetized inducti
vely coupled plasma ( ICP )
报告人:李长君
组员:周涛涛 刘皓东 李长君 吴凯 任杰 刘沛航
introductionmetastable argon ion (in magnetized
inductively coupled plasma)LIF
velocity distribution functions
metastable ion density and temperature
construct a model
theoretical model for Tion
MICP chamber
fluorescence (442.72nm)
laser (668.61nm)
plasma(generated at 13.56MHz)
Pyrex tubestainless steel chamber
grounded electrode
single-turn antenna
bandpass optical filter (1nm bandwidth) PM tubefiber
Langmuir probe
Measured metastable ion velocity distribution function
FWHMT
arean
i
mi
Theoretical model for metastable ion density
Metastable ion density vs electron density when rf power changes
neutrals ions
)1(1
103
101,1.0216
mTorrmf
cm
scmLeVT
CT
cross
i
e
,
zero-dimensional rate equation
electron-impact excitation coefficient
Electron temperature, electron density, and plasma potential as a function of pressure, rf power, and B field.
Comparison between measured metastable ion density and calculated metastable ion density as a function of pressure, power, and B field. Bothdensities are normalized to 1
ni=107~109cm-3
dc bias effect
• ion heating sources: electron-ion collisions, the acceleration from spatial potential, and wave-particle interactions.
biasVVV p
Theoretical model for ion temperaturespatial potential →additional vdrift
collide with other ions and neutrals
transfer energy
increase Ti and Tn
charge exchange wiith a neutral
convert to neutral kinetic energy
Ti and Tn ← energy balance equation
electron collisions the acceleration from spatial potential
neutral collisionswall collisions
electrons and ions lose by the neutral collisions
wall collisions