| Abstract: | In this paper, volume barrier discharge with different gap distances is added on the discharge border of high-voltage electrode of annular surface barrier discharge for generating volume added surface barrier discharge (V-SBD) excited by bipolar nanosecond high-voltage pulse power in atmospheric air. The excited V-SBDs consist of surface barrier discharge (d=0 mm) and volume added surface barrier discharges (d=2 mm and 3 mm). The optical emission spectra are recorded for calculating emission intensities of N2 (C 3Ⅱu →B3Πg ) and N2+ (B 2Σu+ → X 2Σg+ ), and simulating rotational and vibrational temperatures. The influences of gap distance of V-SBD on emission intensity and plasma temperature are also investigated and analyzed. The results show that d=0 mm structure can excite the largest emission intensity of N 2 (C 3 Πu →B 3Πg ), while the existence of volume barrier discharge can delay the occurrence of the peak value of the emission intensity ratio of N2+ (B 2Σu+ → X 2Σg+ )/N 2(C3Πu →B3Πg ) during the rising period of the applied voltage pulse and weaken it during the end period. The increasing factor of emission intensity is effected by the pulse repetition rate. The d=3 mm structure has the highest threshold voltage while it can maintain more emission intensity of N2(C3 Π u →B 3Πg ) than that of d=2 mm structure. The structure of d=2 mm can maintain more increasing factor than that of the d=3 mm structure with varying pulse repetition rate. Besides, the rotational temperatures of three V-SBD structures are slightly affected when the gap distance and pulse repetition rate vary. The vibrational temperatures have decaying tendencies of all three structures with the increasing pulse repetition rate. |
