A method for the assessment of x-ray doses from laser plasma sources

A method for assessing ionising radiation doses from laser plasma sources is presented. Results of an example used to demonstrate the method indicate that, under the assumptions of the analysis, the directional dose equivalent at 0.07 mm depth (H'(0.07)) for photon energies Ep greater than or equal to 10 keV is 75 μSv J-1 of laser energy, assessed at 1 m (dry air) from a plasma source. The highest component of this dose equivalent (∼ 12 μSv J-1 keV-1) results from photons of energy around 10 keV. For the same example, the directional dose equivalent at 10 mm depth (H'(10)) for Ep ≥ 10 keV is 20 μSv J-1; the highest component of which (∼ 1.3 μSv J-1 keV-1) resulting from photons of energy between 15 and 20 keV. Further examples given in this study predict the reduction in the dose equivalents when additional attenuating media are used between the source and an exposed person. (author)