A triboelectric x-ray source

Abstract

A source of x-rays capable of exciting the characteristic emission lines of Mo and Ag is demonstrated. The device, which requires no external high voltage supply, uses the triboelectric effect to produce a charge imbalance when silicone and a metal-loaded epoxy are made to repeatedly contact each other in vacuum. This provides a source of 40 keV electrons which generate bremsstrahlung and characteristic x-rays at a rate of >105 per contact cycle. By increasing the repetition rate of the contact cycle the viability of a device that emits 108 x-ray photons per second is suggested, making triboelectricity an inexpensive source of x-rays. The form factors and simplicity of such devices open up interesting possibilities for x-ray imaging.

Characterization of a triboelectric x-ray spectrum

“…We have used the X-ray spectra with Mo target data measured in [2] and parametrized spectra data of an X-ray tube with Mo anode reported in [3] using the next relation which was proposed by J. Boone et al …”

“…Additionally, each spectra was corrected for their particular measurement conditions. We have applied an attenuation correction to the spectrum which was measured in [2] for 6 mm poly-carbonate window (C 16 H 14 O 3 ) and we have applied the attenuation correction on the spectra reported in [3] for 70 cm of air thickness. Both spectrum were exponentially attenuated assuming attenuation coefficients from NIST.…”

“…Recently, Camara et al [1] and most recently Hird et al [2] have produced low-energy X-rays using the triboelectric effect. According to Hird et al [2] 40 keV electrons and polyenergetic X-Rays can be generated (using a device based on the triboelectric effect), when silicone and a metal-loaded epoxy are repeatedly made contact to each other in vacuum. The characterization of an X-ray beam can be done in terms of the intensity or the penetration, in this work we are interested in the beam penetration.…”

“…The HVL computation was made using the X-ray spectra data measured in [2] and the parametrized spectra obtained in [3]. The parametrized spectra allows us to compute the spectra voltage which has the same HVL.…”

A stroke of X-ray

“…Writing in Applied Physics Letters, Hird et al 2 now describe how they have developed a prototype that promises to turn this principle of Xray production into a simple, lowcost Xray source.…”