Intensity of Diffracted X-rays from Biomolecules with Radiation Damage Caused by Strong X-ray Pulses

In order to realize the coherent X-ray diffractive imaging of single biomolecules, the diffraction intensities, per effective pixel of a single biomolecule with radiation damage, caused by irradiation using a strong coherent X-ray pulse, were examined. A parameter survey was carried out for various experimental conditions, using a developed simulation program that considers the effect of electric field ionization, which was slightly reported on in previous studies. The two simple relationships among the parameters were identified as follows: (i) the diffraction intensity of a biomolecule slightly increases with the incident X-ray energy; and that (ii) the diffraction intensity is approximately proportional to the target radius, when the radius is longer than 400 A, since the upper limit of the incident intensity for damage to the biomolecules marginally changes with respect to the target radius.