Non-Uniformity of Heavy-Ion Beam Irradiation on a Direct-Driven Pellet in Inertial Confinement Fusion

摘要

Heavy-ion-driven fusion （HIF）is a scheme to achieve inertial confinement fusion（ICF）.Investigation of the non-uniformity of heavy-ion beam （HIB）irradiation is one of the keyissues for ICF driven by powerful heavy-ion beams.Ions in HIB impinge on the pellet surfaceand deposit their energy in a relatively deep and wide area.Therefore,the non-uniformity of HIBirradiation should be evaluated in the volume of the deposition area in the absorber layer.Byusing the OKI code with some corrections,the non-uniformity of heavy-ion beam irradiation forthe different ion beams on two kinds of targets were evaluated in 12-beam,20-beam,60-beamand 120-beam irradiation schemes.The root-mean-square （RMS）non-uniformity value becomes(Trms = 8.39% in an aluminum mono-layer pellet structure and σRMS= 6.53% in a lead-aluminumlayer target for the 12-uranium-beam system.The RMS non-uniformity for the lead-aluminumlayer target was lower than that for the mono-layer target.The RMS and peak-to-valley （PTV）non-uniformities are reduced with the increase in beam number,and low at the Bragg peak layer.