X-ray photons produced from a plasma-cathode electron beam for radiation biology applications

Abstract

A compact low-energy and high-intensity x-ray source for radiation biology applications is presented. A laser-induced plasma moves inside a 30 kV diode and produces a beam of 1014 electrons at the anode location. An aluminum foil converts a part of the energy of these electrons into x-ray photons, which are characterized using filtered imaging plates. The dose that would be deposited by these x-ray photons in C. elegans larvae is calculated from Geant4 simulations. It can be set to a value ranging between 10 μGy and 10 mGy per laser shot by simply changing the aluminum foil thickness and the diode voltage. Therefore, this versatile and compact x-ray source opens a new path to explore the radiation effects induced by dose rates varying over several orders of magnitude.

Expected yields of $^{181}$Ta (e,e') $^{181}$Ta$^*$ in the multi-keV range with a plasma-cathode electron beam

“…The experiment is even more complicated as a strong flash of X-ray photons will be emitted during the slowing down of the incident electrons in the anode over a duration of a few tens of ns. In a previous study [29], we have shown that the total energy of the photons of this flash was of the order of 10 9 to 10 10 keV in the backside of a 15 µm thick aluminum anode. Such an amount of energy cannot totally relax in a scintillator or semiconductor detector [30] over a few tens of µs, i.e.…”