Specific features of radiation from a negative air corona operating in the Trichel-pulse mode
- PDF / 240,122 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 61 Downloads / 160 Views
MPERATURE PLASMA
Specific Features of Radiation from a Negative Air Corona Operating in the Trichel-Pulse Mode V. I. Karas’, V. I. Golota, O. V. Bolotov, B. B. Kadolin, and D. V. Kudin National Science Center Kharkiv Institute of Physics and Technology, National Academy of Sciences of Ukraine, vul. Akademichna 1, Kharkiv, 61108 Ukraine Received February 6, 2008
Abstract—Experimental studies of spatiotemporal characteristics of radiation from a negative corona operating in the Trichel-pulse mode in the point-to-sphere electrode geometry have revealed two emission zones. In addition to the well-known glow near the point electrode, there is also an anode glow, whose intensity depends substantially on the shape of the anode. It is found that the anode glow is delayed with respect to the beginning of the Trichel pulse by a time that depends on the gap length and gap voltage. The emission spectrum of the anode glow in the wavelength range 300–400 nm is identified as the spectrum of the second positive system of nitrogen (the C3Πu–B3Πg transition). PACS numbers: 52.25.Os, 52.80.-s, 52.80.Hc DOI: 10.1134/S1063780X08100097
1. INTRODUCTION Studies of corona discharges continue to be a topical problem because a self-consistent model capable of adequately describing the formation and evolution of this type of discharge is still lacking. It is of special interest to study a negative corona in short gaps at atmospheric pressure. Such a discharge is self-sustained and forms in highly inhomogeneous electric fields characteristic of the point-to-plane electrode geometry in which the discharge is maintained by applying a negative potential to the point electrode. There is a range of discharge voltages in which the discharge current represents a steady-state sequence of the so-called Trichel pulses [1]. An increase in the gap voltage (the other conditions being the same) leads to a decrease in the pulse amplitude and an increase in the pulse repetition rate. At a sufficiently high voltage, the discharge passes into to a diffuse phase [2], in which the current flowing through the discharge gap is constant [3]. As a rule, in constructing a model of a negative corona, the discharge gap is conventionally divided into two regions. A bright ~1-mm-long region adjacent to the corona electrode is referred to as the active zone. This zone is characterized by a high reduced electric field and intense generation of charged particles. The rest of the discharge gap is referred to as the drift zone. The electric field in the drift zone is too low for charged particles to gain an energy necessary for intense ionization; therefore, the current in this region is primarily provided by the drift of negatively charged particles toward the anode. Experimental studies of the spatiotemporal characteristics of radiation from the active zone of a low-pressure corona discharge were reported
in [4]. In [5], a model was proposed that described the establishment of a sequence of Trichel pulses in a corona discharge in air after applying a voltage to the dischar
Data Loading...
