Whitepaper #302 in the Decadal Survey for Solar and Space Physics (Heliophysics) 2024-2033. Main topics: basic research. Additional topics: fundamental space plasma theory; solar physics.
Magnetic reconnection plays an important role in solar flares, but it remains unclear if or how magnetic reconnection can further explain particle acceleration to high energies during flares. We argue that the key issue is the lack of understanding of the precise context of particle acceleration, and it can be overcome, in the near future, by performing imaging-spectroscopy in soft X-rays (SXRs).