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The properties of solar flare plasma can be determined from the observationof optically thin lines. The emitting ion distribution determines the shape ofthe line, with an isothermal Maxwellian ion distribution producing a Gaussianprofile. Non-Gaussian lines may indicate more complex ion distributions. Weinvestigate the possibility of determining flare-accelerated non-thermal ion orplasma velocity distributions. We study EUV spectral lines during a flareSOL2013-05-15T01:45 using the Hinode EUV Imaging Spectrometer (EIS). The flareis located close to the eastern solar limb with an extended loop structure,allowing the different flare features: ribbons, hard X-ray (HXR) footpoints andthe loop-top source to be clearly observed in UV, EUV and X-rays. EUV linespectroscopy is performed in seven different regions. We study the lineprofiles of isolated and unblended Fe XVI lines (262.976 A) formed attemperatures of 2-4 MK. Fe XVI line profiles at one time close to the peak softX-ray emission and free of directed mass motions are examined using: 1. ahigher moments analysis, 2. Gaussian fitting, and 3. by fitting a kappadistribution profile convolved with a Gaussian to account for the EISinstrumental profile. Fe XVI line profiles in the loop-top, HXR footpoint andribbon regions can be confidently fitted with a kappa line profile, giving low,non-thermal kappa values between 2-3.3. A higher moments analysis also findsthat many of the line kurtosis values are higher than the Gaussian value of 3,even with the presence of a broad Gaussian instrumental profile. Aflare-accelerated non-thermal ion population could account for both theobserved non-Gaussian line profiles, and for the Fe XVI excess broadening foundfrom Gaussian fitting, if the emitting ions are interacting with a thermalised4 MK electron population, and the instrumental profile is well-approximated bya Gaussian.

First evidence of non-Gaussian solar flare EUV spectral line profiles and accelerated non-thermal ion motion