Modeling of Solar Flare Plasma and Its Radiation

We present a modular and highly versatile test particle-radiative hydrodynamic code which simultaneously models the particle beam energy transport and deposition, the corresponding explosive response of the flare atmosphere and the NLTE (NLTE, plasma and radiation out of the local thermodynamic equilibrium) radiative transfer for partly ionized hydrogen in the chromosphere and photosphere. The computational domain covers the photosphere, the chromosphere, the transition region, and the corona with the initial hydrostatic preflare atmosphere. To demonstrate the potential of the code, we calculate the time evolution of the Balmer line profiles corresponding to the time variation of the electron beam flux derived from the observed flare hard X-ray emission.