The simulation of 100 eV positrons transmitted in conical capillary was performed with inserted beam intensity from 0.04 fA/mm to 10 fA/mm. At lower injected intensity of sub-fA, the transmission profile is geometrical and dominated by direct transmission. As the tilt angle increases, the intensity of the transmitted positron decreases rapidly, which is consistent with the experimental data. After increasing injected current intensities to several fA/mm, charge deposited in the capillary significantly enhances the transmission rate, and the positrons can transmit the capillary with larger tilt angles. The transmitted current density is shown to increase up to a factor of 4.8 with respect to the injected one. These results provide evidence that the low-energy positrons can be guided and significantly focused by insulating conical capillary.

中文翻译：

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模拟 100 eV 正电子通过锥形毛细管的动态传输

模拟了在锥形毛细管中传输的 100 eV 正电子，插入光束强度为 0.04 fA/mm 至 10 fA/mm。在 sub-fA 的较低注入强度下，传输剖面是几何形状的，并且以直接传输为主。随着倾斜角度的增大，透射正电子的强度迅速降低，这与实验数据一致。将注入电流强度增加到几个fA/mm后，沉积在毛细管中的电荷显着提高了传输速率，并且正电子可以以更大的倾斜角度传输毛细管。传输电流密度相对于注入电流密度增加了 4.8 倍。这些结果证明低能正电子可以通过绝缘锥形毛细管进行引导和显着聚焦。