In ion fast ignition (FI) inertial confinement fusion (ICF), a laser accelerated ion beam called igniter provides energy required for ignition of a fuel pellet. The laser accelerated deuteron beam is considered as igniter. The deuteron beam with Maxwellian energy distribution produced at the distance d = 500 μm, from fuel surface, travels during time t = 20 ps and arrives with power P1D(t, TD) to the fuel surface. Then, the deuteron beam deposits its energy into fuel by Coulomb and nuclear interactions with background plasma particles during time t = 10 ps, with power P2D(t, TD, Tb). Since time and power of the two stages have same order, to calculate the total power deposited by igniter beam, both stages must be considered simultaneously. In this paper, the exact power of each stage has been calculated separately, and the total power Ptotal(t, TD, Tb) has been obtained. The obtained results show that the total power deposition Ptotal(t, TD, Tb) is significantly reduced due to reducing different temperature between projectile and target particles.
