The ratios of intensities of the spectral bands of molecular nitrogen corresponding to transitions N + 2 (B 2 + g , v = 0) → N + 2 (X 2 + g , v = 0), N 2 (C 3 u , v = 0) → N 2 (B 3 g , v = 0) and N 2 (C 3 u , v = 2) → N 2 (B 3 g , v = 5) as a function of the applied electric field strength were measured for air in the pressure range of 300 to 10 5 Pa. The non-self-sustaining dc discharge in a parallel-plane gap was used for excitation of gas molecules. The reduced field strength was varied in the range of (150-5000) × 10 −21 V m 2. The measured ratio of intensities as a function of electric field strength is compared with the theoretical estimates made by other authors. The obtained intensity ratio versus field strength curves can be used for field strength estimation in plasmas if the nitrogen molecules are excited dominantly from the ground state directly by the electron impact.

This paper presents an experimental investigation of the effect of the electric field strength on the collisional quenching rate of nitrogen states N 2 (C 3 Π u , v = 0) and N 2 + (B 2 Σ + g , v = 0) by nitrogen and oxygen molecules. In experiments, the pulses of non-self-sustained electrical discharge excite gas molecules. The range of reduced electric field strength is from 240 to 4000 Td at pressure range from 70 to 4300 Pa. The experiments show that the field strength has no effect on the quenching rate. The paper discusses the probable reasons for discrepancy of results obtained by different authors and proposes the preferable values for rate coefficients. These coefficients can be used for electric field determination in low temperature gas discharge plasmas via nitrogen emission spectrum, and are of interest to atmospheric air fluorescence investigations.

The provision of a particle and power exhaust solution which is compatible with first-wall components and edge-plasma conditions is a key area of present-day fusion research and mandatory for a successful operation of ITER and DEMO. The work package plasma-facing components (WP PFC) within the European fusion programme complements with laboratory experiments, i.e. in linear plasma devices, electron and ion beam loading facilities, the studies performed in toroidally confined magnetic devices, such as JET, ASDEX Upgrade, WEST etc. The connection of both groups is done via common physics and engineering studies, including the qualification and specification of plasma-facing components, and by modelling codes that simulate edge-plasma conditions and the plasma-material interaction as well as the study of fundamental processes. WP PFC addresses these critical points in order to ensure reliable and efficient use of conventional, solid PFCs in ITER (Be and W) and DEMO (W and steel)

The absorption characteristics of photo‐ionizing VUV radiation emitted by corona discharges in the pressure range from 20 to 750 Torr in dry and humid air were measured. The experimental results are compared with data and approximation formulae obtained by others. For a wide region of pressure and absorption path length, the formula proposed by Zheleznyak et al. (Teplofiz. Vysokih Temp. 1982, 20, 423) seems to be the most reliable for approximation of our results for dry air. We propose a modification of that formula for humid air. The obtained results are suitable for modelling of discharge development in ambient air.

The ratio of intensities of the first negative system and the second positive system of nitrogen as a function of the electric field strength was experimentally determined in atmospheric-pressure air. The non-self-sustained discharge was excited in a parallel-plane gap using the radiation of a pulsed laser. The field strength was varied in the range of 135-285 Td. The peculiarities of the measurement and data processing of signals of very low intensity are described. The results are compared with the theoretical predictions of other authors.