Characterization of low-pressure microwave and radio frequency discharges in oxygen applying optical emission spectroscopy and multipole resonance probe

Electrical, optical and spectroscopic characterisation of a radio frequency discharge used for electrosurgical cutting

“…These emission transitions have high Einstein coefficients and therefore a high enough intensity. The excitation mechanism of these bands by electron impact is well known with well‐known cross sections . The intensity of the corresponding nitrogen emission ( in photons · s −1 · cm −3 ) is equal to the integral in the measured emission spectrum ( in counts · s −1 · nm −1 ) under a profile of the vibrational band of corrected by the efficiency of the spectrometer ( in counts · photons −1 ) and divided by the plasma volume ( in cm 3 ), the geometrical factor (), the duration of the discharge pulse ( in s) and the repetition rate of the discharge pulses ( in s −1 ) (1).…”

Spectroscopic and Microscopic Investigations of Degradation Processes in Polymer Surface‐Near Regions During the Deposition of SiOx Films

“…Apertures mounted to the fibres determined the acceptance angles or cones and therefore, the observed plasma volume. For the determination of the plasma volume a geometrical factor was considered . The measured emission was corrected by the spectral sensitivity of the used spectrometers and the intensity (in phot.…”

“…The intensities of photoemission of nitrogen molecular bands N 2 (CB, 00) and N 2 + (BX, 00) were used to determine the electron density and electron distribution function assuming a Maxwellian distribution of the free electrons. Therefore, a collisional‐radiative (cr) model was applied that takes into account stepwise electron impact excitation processes including metastable N 2 (A) and ground state molecular ion N 2 + (X) states . Furthermore, direct excitation processes from molecular nitrogen ground state N 2 (X) were considered.…”

“…The steady‐state absolute atomic oxygen density was determined by measuring the intensity of photoemission at λ = 844.6 nm (O( 3 P(2s 2 2p 3 (4S 0 ) 3p)) to O( 3 S(2s 2 2p 3 (4S 0 ) 3s))) and taking into account the plasma parameters and excitation cross sections . Therefore, direct electron‐impact and dissociative excitation was taken into account leading to an expression for the atomic oxygen density N O in Equation 1 …”

“…Electron density n e and temperature T e were calculated using the above mentioned cr‐model. A discussion of typical systematic errors associated to this procedure can be found elsewhere . The assumption of cylindrical symmetry of the plasma and a Maxwellian distribution for the atomic oxygen particle speed led to the fluence: where denotes the mean particle speed and t dep the deposition time.…”