Authors: Dillon anderson (Montana State University), Rachael Filwett (Montana State University)

Near-sun measurements of solar energetic particles (SEPs) provide an opportunity to probe acceleration processes with reduced influence from interplanetary transport effects. We analyze spectra from 14 gradual SEP events observed by Parker Solar Probe and Solar Orbiter at heliocentric distances ≤ 0.43 au. The analysis uses measurements over ~1 – 120 MeV/nuc for Parker Solar Probe, and ~0.05-170 MeV/nuc for Solar Orbiter. The event-integrated spectra for multiple ion species are fit with the four-parameter Band function. We then find the strength of the charge-to-mass dependence of the spectral roll-over energy, E_x/E_H ∝ (Q_x/M_x)^α. A statistically significant positive correlation was found between α and heliocentric distance (Spearman ρ = 0.546, and p = 0.035), suggesting that the acceleration conditions driving the charge-to-mass dependence of SEP spectra may evolve with heliocentric distance in the inner-heliosphere.