  Impulsive solar energetic particle (SEP) events originate from the energy
dissipation process in small solar flares. Anomalous abundances in impulsive
SEP events provide an evidence on unique, yet unclear, acceleration mechanism.
The pattern of heavy-ion enhancements indicates that the temperature of the
source plasma that is accelerated is low and not flare-like. We examine the
solar source of the $^3$He-rich SEP event of 2012 November 20 using Solar
Dynamics Observatory (SDO)/ Atmospheric Imaging Assembly (AIA) images and
investigate its thermal variation. The examined event is associated with
recurrent coronal jets. The Differential Emission Measure (DEM) analysis is
applied to study the temperature evolution/distribution of the source regions.
Preliminary results show that the temperature of the associated solar source is
ranged between 1.2-3.1 MK.
