ICDA-5

Characterization of Ionizing Radiation Components in High-Voltage Switching Impulse Discharges Using Passive Detectors

Jun 10, 2026, 4:06 PM

2m

CTU in Prague, Faculty of Nuclear Sciences and Physical Engineering (Prague, Czechia)

Poster Environmental dosimetry and monitoring Poster session

Speaker

Ondřej Ploc (Department of Radiation Dosimetry, Nuclear Physics Institute of the Czech Academy of Sciences, Na Truhlářce 39/64, Prague, 180 00, Czechia)

Description

This study investigates the radiation field generated during high-voltage switching impulse discharges, extending our prior work that confirmed photon/electron and neutron radiation components for atmospheric impulses (1.2/50 μs waveform) using passive detectors. While the atmospheric impulse waveform has been extensively studied in the context of lightning discharge simulation, the switching impulse waveform (250/2500 μs) has received considerably less attention, despite its practical relevance to the simulation of switching overvoltages in power systems and long-duration atmospheric discharges. Critically, although a photon/electron radiation component has been reported for switching impulses in the literature, the potential presence of a neutron component has not been investigated.
Two measurement campaigns were conducted using a high-voltage generator operating at 1.6 MV with rod–plate electrodes separated by a 1.5 m gap. Fifty negative vertical discharges were initiated per campaign. Passive detectors were chosen to mitigate electromagnetic interference from high-voltage, high-current pulse generation. In the first campaign, thermoluminescence detectors (CaSO₄, MTS-6, MTS-7, MTS-N) were positioned at the cathode rod and at heights of 1 m and 1.5 m above the ground electrode, 1 m from the discharge axis, to enable discrimination between photon/electron and neutron components and to allow direct comparison with prior atmospheric impulse experiments. The second campaign introduced personal film dosimeters and gafchromic films (XRQA2, LD-V1) — the latter placed on the ground electrode and along the discharge axis — providing spatially resolved measurements of localized radiation phenomena over extended areas. Discharges were documented using high-speed cameras throughout both campaigns.
Preliminary results for thermoluminiscence detectors indicate a statistically significant absorbed dose attributable to the photon/electron radiation component at 1 m above the ground electrode, relative to background. These findings underscore the importance of systematically characterizing radiation emissions across different high-voltage impulse waveforms, with implications for both laboratory safety and broader understanding of discharge-induced radiation phenomena.