Spatially-resolved Observation of the Excitation Temperature in a Glow Discharge Plasma for Atomic Emission Spectrometry

Two-dimensional Observation of Emission Image of a Copper Chip Excited in a Glow Discharge Plasma

“…Our previous paper had already represented an emission image of a pure copper plate covering over the whole emitting zone of glow discharge plasma, indicating that the emission of the sample was not irradiated uniformly over the plasma zone but the central portion, having a diameter of about 2 mm, gave the most intense emission and then the intensity was largely reduced towards the surrounding zone of the plasma. 5,6) It should be thus noted that the intensity map in Fig. 2 was overlapped with the intensity variation of the plasma itself.…”

“…5) Our previous papers reported on spectral images of zinc and copper samples by using a two-dimensionally imaging spectrometer having a spectral resolution of less than 1 nm, indicating that the intensities of their emission lines were not uniform over the plasma area, but were drastically reduced along the radial direction of the plasma. 5,6) This effect was because the number density of the analyte species was inhomogeneous in the plasma.…”

Spatially-resolved Spectral Image of a Microwave-induced Plasma with Okamoto-cavity for Nitridation of Steel Substrate

“…glow discharge plasmas by using this measuring system. [17][18][19] The imaging spectrograph system comprised a collimator, an image spectrograph and a charge-couple device (CCD) detector. 17 The emission signal from the MIP was introduced through the collimator onto the entrance slit of the spectrograph (Model 12580, BunkoKeiki Corp., Japan), dispersed at a certain wavelength, and then detected on the CCD detector (SensiCam QE Model, PCO Imaging Corp., Germany), where the 2D image of a particular band head could be observed in the axial and radial directions of the plasma.…”

“…It was determined by measuring an image of a scale that a 2D image having 10 × 10 pixels approximately corresponded to an actual sample area of 0.20 × 0.20 mm 2 . 18 The data were accumulated and averaged on a personal computer to reduce the intensity fluctuation, and the plasma images were finally recorded.…”

Spatially Resolved Observation of a Radio-Frequency-Powered Glow Discharge Plasma for Emission Spectrometric Analysis

“…Our previous papers reported on 2D spectral images of zinc, copper and iron samples by using a twodimensionally imaging spectrometer having a spatial resolution of less than 1 nm, indicating that the intensities of their emission lines were not uniform over the plasma area, but were drastically reduced from the center of the plasma toward the outside. [8][9][10] It is important to understand the reason why such a spatial distribution of the emission intensities occurs, in order to clarify the excitation mechanism occurring in the glow discharge plasma. Two possible reasons should be considered, as follows: (1) the emission efficiency is inhomogeneous in the plasma, and (2) the number density of analyte species is inhomogeneous in the plasma.…”