The T6 ion thruster is providing in-space propulsion for the BepiColombo mission, currently en route to Mercury. Simulations of the accelerator grid erosion during flight operation were carried out using the CEX2D and CEX3D codes in order to verify that the grid lifetime will be sufficient to impart the 5.75 $\mathrm{M}\mathrm{N}\cdot \mathrm{s}$ total impulse per thruster required for the mission. Before calculating in-space erosion rates, the models were benchmarked against data from long-duration wear tests. Two-dimensional simulations tracked the time-dependent grid geometry and calculated changes in the electron backstreaming limit $V_{\mathrm{EBS}}$ as the grids eroded. Sensitivity studies assessed the impact of uncertainty in the operating screen-to-accelerator grid gap on $V_{\mathrm{EBS}}$. Three-dimensional simulations employed a particle-in-cell model for the charge exchange ions and were able to accurately reproduce the nonaxisymmetric pits and grooves erosion pattern observed on the downstream face of the accelerator grid following ground testing. Charge exchange ion space charge effects were found to broaden the pit erosion features in flight, further reducing the peak erosion rate relative to that observed on the ground. The simulations predicted that T6 will have sufficient margin against both electron backstreaming and accelerator grid wearthrough over the duration of the mission.

T6离子推进器正在为BepiColombo任务提供太空推进，该任务目前正在途中到达水星。使用CEX2D和CEX3D代码对飞行过程中加速器格栅腐蚀进行了仿真，以验证格栅寿命足以赋予5.75。$\mathrm{中号}\mathrm{ñ}\cdot \mathrm{s}$任务所需的每个推进器总脉冲数。在计算空间侵蚀率之前，将模型与长期磨损测试的数据进行基准比较。二维模拟跟踪了随时间变化的网格几何形状，并计算了电子回流极限的变化$V_{\mathrm{电子业务系统}}$随着网格的侵蚀。敏感性研究评估了屏幕与加速器之间的电网间隙不确定性对$V_{\mathrm{电子业务系统}}$。三维模拟对电荷交换离子采用了单元粒子模型，并能够精确再现地面测试后在加速器格栅下游面上观察到的非轴对称凹坑和沟槽腐蚀图案。发现电荷交换离子空间电荷效应扩大了飞行中的坑蚀特征，相对于在地面上观察到的峰蚀率进一步降低了。仿真预测，在任务执行期间，T6将具有足够的余量来抵制电子回流和加速器格栅的磨损。