A5071694896- Lightning and Electromagnetic Phenomena
- Ionosphere and magnetosphere dynamics
- Electrostatic Discharge in Electronics
- Earthquake Detection and Analysis
- Nuclear Physics and Applications
- High voltage insulation and dielectric phenomena
- Plasma Diagnostics and Applications
- Fire effects on ecosystems
- Radiation Detection and Scintillator Technologies
- Meteorological Phenomena and Simulations
- Solar and Space Plasma Dynamics
- Medical Imaging Techniques and Applications
- Power Line Communications and Noise
- Particle Detector Development and Performance
- Pulsed Power Technology Applications
- Astrophysics and Cosmic Phenomena
- Radioactive Decay and Measurement Techniques
- Atmospheric aerosols and clouds
- Ocular and Laser Science Research
- Advanced Optical Sensing Technologies
- Advanced X-ray and CT Imaging
- Plasma Applications and Diagnostics
- Laser Design and Applications
- Atomic and Subatomic Physics Research
- Thermal Analysis in Power Transmission
University of Bergen
2016-2022
Br. Birkeland (Norway)
2016-2022
Eindhoven University of Technology
2012-2017
Renewable Energy Systems (United States)
2012-2017
We investigate the development of meter long negative discharges and focus on their X-ray emissions.We describe appearance, timing spatial distribution X-rays.They appear in bursts nanosecond duration mostly cathode area.The spectrum can be characterized by an exponential function with 200 keV characteristic photon energy.With nanosecond-fast photography we took detailed images pre-breakdown phenomena during time when X-rays were registered.We found bipolar discharge structures, also called...
Terrestrial gamma-ray flashes (TGFs) are transient emissions from thunderstorms, generated by electrons accelerated to relativistic energies in electric fields. Elves ultraviolet and optical excited the lower ionosphere electromagnetic waves radiated lightning current pulses. We observed a TGF an associated elve using Atmosphere-Space Interactions Monitor on International Space Station. The occurred at onset of pulse that elve, early stage flash. Our measurements suggest is fast has high...
Abstract The Atmosphere‐Space Interactions Monitor (ASIM) was launched to the International Space Station on 2 April 2018. ASIM payload consists of two main instruments, Modular X‐ray and Gamma‐ray Sensor (MXGS) for imaging spectral analysis Terrestrial Flashes (TGFs) Multi‐spectral Imaging Array detection, imaging, Transient Luminous Events lightning. is first space mission designed simultaneous observations Events, TGFs, optical During 10 months operation (2 June 2018 1 2019) MXGS has...
We investigate structure and evolution of long positive spark breakdown; we study at which stage pulses hard X-rays are emitted. Positive high-voltage standardized lightning impulse wave form about 1 MV were applied to meter ambient air. The discharge was imaged with a resolution tens nanoseconds an intensified CCD camera. LaBr3(Ce+) scintillation detectors recorded the emitted during process. voltage currents on both electrodes measured synchronously. All measurements indicate that first...
We study the development of a negative discharge driven by Marx generator about 1 MV in an air gap up to 1.5 meter, at standard temperature and pressure. show evolution with nanosecond-fast photography together electrical characteristics. The develops through four well-distinguished streamer bursts. streamers have different velocities life times last burst triggers positive inception cloud on grounded electrode counter-streamers emerges. pre-discharge then bridges leaders grow from both...
An Airbus A340 aircraft flew over Northern Australia with the In-Flight Lightning Damage Assessment System (ILDAS) installed onboard. A long-duration gamma ray emission was detected. The most intense observed at 12 km altitude and lasted for 20 s. Its intensity times background counts, it abruptly terminated by a distant lightning flash. In this work we reconstruct path event timeline. glow-terminating flash triggered discharge from wing that recorded video camera operating Another count...
When voltage pulses of 1 MV drive meter long air discharges, short and intense bursts x-rays are measured. Here we develop a model for electron acceleration subsequent photon generation within this discharge to understand these bursts. We start from the observation that encounter two streamers opposite polarity launches electrons, they further accelerated in field then lose their energy, e.g., by emission through Bremsstrahlung. dynamics space energy with Monte Carlo model. Also detector...
The Modular X- and Gamma-ray Sensor (MXGS) is an imaging spectral instrument mounted on the starboard side of Columbus module International Space Station. Together with Multi-Spectral Imaging Assembly (MMIA) (Chanrion et al. this issue) MXGS constitutes instruments Atmosphere-Space Interactions Monitor (ASIM) (Neubert issue). main objectives are to image measure spectrum $\gamma $ -rays from lightning discharges, known as Terrestrial Flashes (TGFs), for MMIA perform high speed photometry...
Abstract On February 8, 2019, the Atmosphere‐Space Interaction Monitor observed a terrestrial gamma‐ray flash (TGF) and an Elve from positive intracloud (+IC) lightning during initial breakdown stage of north east Puerto Rico. A second produced by return stroke (RS) negative cloud‐to‐ground (−CG) was 456 ms later about 300 km south first one. Radio measurements show that short (30 μs) large (280 kA km) energetic in‐cloud pulse (EIP) electromagnetic (EM) wave for while RS −CG EM source Elve....
Abstract The Atmosphere‐Space Interactions Monitor (ASIM) is the first instrument in space specifically designed to observe terrestrial gamma‐ray flashes (TGFs). TGFs are high energy photons associated with lightning and we perform spectral analysis of 17 detected by ASIM. TGF sample carefully selected rigorous selection criteria keep a clean suitable for analysis, that is, count statistics, low instrumental effects, reliable source location. Monte Carlo modeling individual has been compared...
The pilot system development in metre-scale negative laboratory discharges is studied with ns-fast photography. systems appear as bipolar structures the vicinity of high-voltage electrode. They a result single streamer propagation and determine further discharge development. Such possess features like glowing beads, bipolarity, different brightness top bottom parts, mutual reconnection. A 1D model ionization evolution spark gap proposed. In process nonlinear growth, shows similar to those...
Abstract Two gamma‐ray glows were observed by a high‐altitude NASA ER‐2 aircraft flying at 20 km altitude over thunderstorm in Colorado, USA. The flux of the first glow rapidly intensified and then abruptly decreased within few tens milliseconds. On timescale seconds, decrease occurred simultaneously with hybrid intra‐cloud/cloud‐to‐ground lightning discharge beneath aircraft. However, more detailed analysis dynamics indicated that activity was unusually calm during actual period decrease....
Discharge experiments were carried out at the Eindhoven University of Technology in 2013. The experimental setup was designed to search for electrons produced meter-scale sparks using a 1 MV Marx generator. Negative voltage applied high (HV) electrode. Five thin (1 mm) plastic detectors (5 $\rm cm^2$ each) distributed various configurations close spark gap. Earlier studies have shown (for HV negative) that X-rays are when cloud streamers is developed 30-60 cm from negative This indicates...
Abstract In the spring of 2017 an ER‐2 aircraft campaign was undertaken over continental United States to observe energetic radiation from thunderstorms and lightning. The payload consisted a suite instruments designed detect optical signals, electric fields, gamma rays Starting Georgia, USA, 16 flights were performed, for total about 70 flight hours at cruise altitude 20 km. Of these, 45 thunderstorm regions. An analysis two ray glow events that observed Colorado 21:47 UT on 8 May is...
Abstract We report a 511‐keV photon flux enhancement that was observed inside thundercloud and is result of positron annihilation. The observation made with the In‐flight Lightning Damage Assessment System (ILDAS) on board an A340 test aircraft. aircraft intentionally flying through thunderstorm at 12‐km altitude over Northern Australia in January 2016. Two gamma ray detectors showed significant count rate increase synchronously fast electromagnetic field variations registered by on‐board...
X-ray emission by sparks implies bremsstrahlung from a population of energetic electrons, but the details this process remain mystery. We present detailed statistical analysis spectra detected multiple detectors during produced 1 MV negative high-voltage pulses with $\mu$s risetime. With over 900 shots, we statistically analyze signals, assuming that distribution spark fluence behaves as power law and energy spectrum X-rays detectable after traversing $\sim$2 m air thin aluminum shield is...
Abstract We report the first Terrestrial Electron Beam detected by Atmosphere‐Space Interactions Monitor. It happened on 16 September 2018. The Monitor Modular X and Gamma ray Sensor recorded a 2 ms long event, with softer spectrum than typically for Flashes (TGFs). lightning discharge associated to this event was found in World Wide Lightning Location Network data, close northern footpoint of magnetic field line that intercepts International Space Station location. Imaging from GOES‐R...
In the certification procedure aircraft builders carry out so-called icing tests flights, where zero degree Celsius altitude is deliberately sought and crossed in or under thunderstorms. Airbus also used these flights to test ILDAS, a system aimed determine lightning severity attachment points during flight from high speed data on electric magnetic field at surface. We this unique opportunity enhance ILDAS systems with two x-ray detectors coupled recorders an attempt x-rays produced by...
Abstract Terrestrial Gamma ray Flashes (TGFs) are short flashes of high energy photons, produced by thunderstorms. When interacting with the atmosphere, they produce relativistic electrons and positrons, a part gets bounded to geomagnetic field lines travels large distances in space. This phenomenon is called Electron Beam (TEB). The Atmosphere‐Space Interactions Monitor (ASIM) mounted on‐board International Space Station detected new TEB event on March 24, 2019, originating from tropical...
Abstract During Airbus aircraft campaigns flying into thunderstorms in 2014–2016, X‐rays were observed during two stages of aircraft‐triggered lightning: nanosecond pulses associated with negative leader steps and bursts recoil events. This work will focus on the observations X‐ray recoils. Recoils are as microsecond‐fast changes local electric field, large currents passing through aircraft, found to sometimes be X‐rays. From over 200 lightning strikes, 54 events microsecond The majority...
Lightning can cause physical damage to the aircraft structure, including wings, nose cone, and other components. This compromise structural integrity of pose a serious risk passenger safety. In addition, it electromagnetic interference that disrupt communications, navigation, essential systems are critical for safe flight.  To better understand impact lightning strikes on aircraft, dataset more than 300 such events has been collected analysed. The mainly covers Scandinavia North...
<p>Terrestrial Gamma-ray Flashes (TGFs) are sub-millisecond bursts of high-energy photons associated with lightning flashes in thunderstorms. The Atmosphere-Space Interactions Monitor (ASIM), launched April 2018, is the first space mission specifically designed to detect TGFs. We will mainly focus on data from High Energy Detector (HED) which sensitive energies 300 keV > 30 MeV, and include Low (LED) 50 370 energy range. Both HED LED part Modular X- Sensor (MXGS)...
The In-flight Lightning Damage Assessment System ILDAS has been presented in EMC Europe 2012. can determine the lightning current distribution on an aircraft with high resolution time and amplitude. Later system was extended included two x-ray detectors to measure high-energy radiation that is generated thunderstorms by proper. It flown for many times now. paper presents a few selected data.