X-rays generated through tribological processes differ from those obtained with conventional X-ray tubes in that a substantial portion of the total energy is emitted in pulses of order 10 ns in duration. The short duration of these pulses usually causes solid-state detectors to register pileup events that can make the corresponding spectrum unreliable as a characterization tool. In this work, we find that a solid angle subtended by the detector of 5×10−6 is necessary to obtain the true spectra of X-rays generated from peeling adhesive tape in a moderate vacuum. The maximum individual photon energy is found to be 30 keV, which is about half of that reported in previous studies that overlook the effects of pileup. Being able to obtain a reliable spectrum may help us understand the physical processes behind this phenomenon so that it can be optimized for present and future applications.

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When an adhesive tape is peeled in vacuum, x rays are generated in burst of short duration (order nanosecond) whose origin is not yet fully understood. In this work, we analyze the electrical discharge dynamics occurring when a pressure-sensitive adhesive tape is peeled from its own backing in x-ray emitting conditions. We characterize these dynamics with the time between consecutive discharges and study its statistical properties as a function of both peeling speed and surrounding air pressure. We find that processes whose dynamics are characterized by shorter timescales generate the high energy portion of the x-ray spectrum. Furthermore, the air pressure affects the emission intensity but not the maximum single photon energy attainable. Our results indicate that there exist more complex physical mechanisms at play than previously thought in this system. Understanding the physical processes behind these dynamics may help improve the yield from devices that use this technology for x-ray production.

x-rays generated through tribological processes are emitted in fast bursts (∼10 ns) that hinder the correct measurement of the corresponding spectrum. In this work we implement a dosimetry technique based on thermoluminescent materials—impervious to pileup problems arising in solid-state active detectors—to measure the angular distribution of the tribo-generated x-rays from peeling adhesive tape. Unexpectedly, we find evidence of an isotropic energy emission on at least one meridian plane. These results may shed light on the physical processes behind the radiation emission in devices that harness the triboelectric effect to generate x-rays, and prove that dosimetry techniques can be used as an alternative characterization tool in the study of the emission from this and other relatively fast systems.