Photospheric Doppler enhancement and Hα evolution of an X-class flare

We present the photospheric Doppler enhancement and Hα brightening of an X-class solar flare from NOAA AR 11748 observed on 2013 May 15. The flare shows two ribbon structure. We observed four velocity enhancement clusters (kernels) associated with the flaring region. Two clusters P & Q of the velocity enhancement that spatially match with the Hα brightening and temporally delayed by 4 min. On the contrary, two other velocity kernels R & S are shifted by 2-3 arcsec from the Hα brightening. We study the localized enhancement in velocity clusters associated with Hα kernels. The time delay in spatially aligned kernels can be interpreted as penetration of proton beam in the solar atmosphere. The shifted velocity enhancement with respect to Hα kernels can be explained by the coupling of energy driven by Lorentz force.