Experimental study of hard X-rays emitted from meter-scale positive discharges in air

Abstract

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 meter 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.

arXiv comment19 pages, 11 figures in Journal of Physics D: Applied Physics 2012

References in corpus (11)

• Positive and negative streamers in ambient air: modeling evolution and velocities
• The multiscale nature of streamers
• Probing photo-ionization: Experiments on positive streamers in pure gasses and mixtures
• Propagation and Structure of Planar Streamer Fronts
• Positive streamers in air and nitrogen of varying density: experiments on similarity laws
• Experimental study on hard X-rays emitted from metre-scale negative discharges in air
• Multiple X-ray bursts from long discharges in air
• Experimental study of the spatio-temporal development of meter-scale negative discharge in air
• 3D hybrid computations for streamer discharges and production of run-away electrons
• Angular distribution of Bremsstrahlung photons and of positrons for calculations of terrestrial gamma-ray flashes and positron beams
• TETRA Observation of Gamma Rays at Ground Level Associated with Nearby Thunderstorms

Cited by in corpus (15)

• The physics of streamer discharge phenomena
• Experimental study on hard X-rays emitted from metre-scale negative discharges in air
• Experimental study of the spatio-temporal development of meter-scale negative discharge in air
• Growing discharge trees with self-consistent charge transport: the collective dynamics of streamers
• Radio emission from negative lightning leader steps reveals inner meter-scale structure
• Spontaneous emergence of space stems ahead of negative leaders in lightning and long sparks
• Pilot system development in metre-scale laboratory discharge
• Relativistic electrons from sparks in the laboratory
• Atmospheric electrification in dusty, reactive gases in the solar system and beyond
• X-ray Emissions in a Multiscale Fluid Model of a Streamer Discharge
• Meter-scale spark X-ray spectrumstatistics
• In-flight measurements of energetic radiation from lightning and thunderclouds
• Estimating the properties of single positive air streamers from measurable parameters
• Macroscopic parameterization of positive streamer heads in air
• Measuring the locations and properties of VHF sources emitted from an aircraft flying through high clouds