  On June 17, 2012, we observed the evolution of a C-class flare associated
with the eruption of a filament near a large sunspot in the active region NOAA
11504. We obtained high spatial resolution filtergrams using the 1.6 m New
Solar Telescope at the Big Bear Solar Observatory in broad-band TiO at 706 nm
(bandpass:10 \AA) and He I 10830 \AA\ narrow-band (bandpass: 0.5 \AA, centered
0.25 \AA\ to the blue). We analyze the spatio-temporal behavior of the He I
10830 \AA\ data, which were obtained over a 90" X 90" field of view with a
cadence of 10 sec. We also analyze simultaneous data from the Atmospheric
Imaging Assembly and Extreme Ultraviolet Variability Experiment instruments on
board the Solar Dynamics Observatory spacecraft, and data from Reuven Ramaty
High Energy Solar Spectroscopic Imager and GOES spacecrafts. Non-thermal
effects are ignored in this analysis. Several quantitative aspects of the data,
as well as models derived using the "0D" Enthalpy-Based Thermal Evolution of
Loops model (EBTEL: Klimchuk et al. 2008) code, indicate that the triplet
states of the 10830 \AA\ multiplet are populated by photoionization of
chromospheric plasma followed by radiative recombination. Surprisingly, the He
II 304 \AA\ line is reasonably well matched by standard emission measure
calculations, along with the C IV emission which dominates the AIA 1600 \AA\
channel during flares. This work lends support to some of our previous work
combining X-ray, EUV and UV data of flares to build models of energy transport
from corona to chromosphere.
