Experimental study of hard x-rays emitted from metre-scale positive discharges in air

By P. Kochkin, C. V. Nguyen, A P J van Deursen, Ute Ebert. 2012

136 citations recorded by the source corpus.

We investigate structure and evolution of long positive spark breakdown; and we study at which stage pulses of hard x-rays are emitted. Positive high-voltage pulses of standardized lightning impulse wave form of about 1 MV were applied to about 1 m of ambient air. The discharge evolution was imaged with a resolution of tens of nanoseconds with an intensified CCD camera. LaBr3(Ce+) scintillation detectors recorded the x-rays emitted during the process. The voltage and the currents on both electrodes were measured synchronously. All measurements indicate that first a large and dense corona of positive streamers emerges from the high-voltage electrode. When they approach the grounded electrode, negative counter-streamers emerge there, and the emission of hard x-rays coincides with the connection of the positive streamers with the negative counter-streamers. Leaders are seen to form only at later stages.

Subfields: Astronomy and Astrophysics, Electrical and Electronic Engineering, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/0015c809313d3c988a942dd753d417b6310e2603

Citations in the corpus

• The physics of lightning (2014, unknown): “[184], reported that ‘‘negative streamers were a necessary and sufficient condition’’ for X-ray production and that most X-rays produced in their studies of long laboratory sparks of either polarity occurred as negative and positive streamers approached each other from the opposite electrodes.”