采用自主研发的三维粒子模拟软件对三腔介质壁加速器进行系统仿真,在此基础上,计算三个腔质子的渡越时间并实现腔体间的时序优化设计。外加电压峰值100 kV,顶宽1 ns,半高宽10 ns,绝缘微堆厚度2.0 cm,质子初始束能40 keV,加速电极添加钨网,模拟结果显示: 当电压持续6.5 ns时, 进入高梯度绝缘微堆的H+通过第一腔能得到最大加速效率90.84%,相应的渡越时间为5.668 ns; 当第二腔电压触发落后第一腔4.5 ns时, H+通过第二腔获得最大加速效率94.77%,相应的渡越时间为3.545 ns; 当第三腔电压触发落后第二腔3.0 ns时, H+通过第三腔获得最大加速效率97.30%,相应的渡越时间为3.018 ns; 最大能量H+渡越三个腔体的总时间为12.231 ns,H+总体加速效率94.31%; 当质子束中心进入第一腔时刻落后脉冲电压触发6.5 ns,且一二腔和二三腔电压触发延时分别为4.5 ns和3.0 ns情形下,能将2.5 ns长度的质子束中的H+实现90%以上的加速,4.0 ns长度的质子束中的H+实现80%以上的加速。

The three cavities dielectric wall proton accelerator is systemically simulated by the self-developed 3D particle simulation software. On this basis, the transit time of protons in three cavities shall be calculated and the timing optimization design between cavities shall be achieved. The impressed voltage peak value is 100 kV. The width at top is 1ns and it is 10 ns at half maximum. The thickness of insulation micro reactor is 2.0 cm. The proton initial energy is 40 keV. The tungsten mesh is added to accelerating electrode. The simulation results are the following: When the voltage lasts 6.5 ns, the H+ which goes into high insulation gradient material shall get a maximum 90.84% acceleration efficiency while passing the first cavity, and the corresponding transit time is 5.668 ns. When the voltage triggers in the second cavity 4.5 ns behinds the first cavity, the H+ shall get a maximum 94.77% acceleration efficiency while passing the third cavity, and the corresponding transit time is 3.545 ns. When the voltage triggers in the third cavity 3.0 ns behinds the second cavity, the H+ shall get a maximum 97.30% acceleration efficiency while passing the second cavity, and the corresponding transit time is 3.018 ns. The total time of the maximum energy H+ transiting the three cavities is 12.231 ns. The acceleration efficiency of total H+ is 94.31%. When the proton beam center enters the first cavity and falls behind the pulse voltage trigger in 6.5 ns, with the delay time between first and second cavities, the second and third cavities are 4.5 ns and 3.0 ns respectively. The H+ of proton beams whose lengths are 2.5 ns and 4.0 ns shall be accelerated above 90% and 80% respectively.