  Based on the Rb$^+$-Rb hybrid trap, we investigate the effect of ion-atom
elastic collisions on the number and temperature of the remaining atoms. We
measured the remaining atomic number and temperature as a function of the
wavelength and intensity of the ionization laser, and whether the ion trap was
turned on. Fittings with a single exponential decay function plus an offset to
the number and radius of the remaining atoms are found to be in good agreement.
We found a difference in the exponential factor of different wavelengths of
ionization laser with the ion trap on or off. We suppose that the presence of
electrons affects ion-atom collisions through disorder-induced heating. Our
research contributes to a better understanding of how ultracold neutral plasma
evolves, particularly the subsequent kinetics of atomic processes, which also
serves as a useful reference for high-energy-density plasma.
