Electron cloud is a persistent problem in operating modern accelerators. It might be eliminated by reducing the secondary electron yield (SEY), which is a property of the material of vacuum chambers. In the present study, the SEYs of oxygen-free copper samples are dramatically mitigated by grooving their surfaces with a laser-etching technique. Such mitigation is realized by trapping incident primary electrons and their induced secondary electrons in the grooves. The SEYs of the laser-etched samples are dependent on the geometrical characteristics of the grooves and the incident angles of the primary electrons, i.e., reducing the incident angle can lead to a reduction in the SEY. Electron bombardment of the grooved surface with an electron dose of 2 × 10⁻² C mm⁻² will further reduce its maximum SEY from 1.15 to 0.98, which might be attributed to the formation of Cu₂O and graphite-like C—C bonds and the removal of surface contaminants.

中文翻译：

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一次电子入射角和电子轰击对激光处理铜的二次电子产率的影响

电子云是操作现代加速器时一直存在的问题。可以通过降低二次电子产率（SEY）消除该现象，这是真空腔室材料的一种特性。在本研究中，无氧铜样品的SEY通过使用激光蚀刻技术在其表面开槽而得到显着缓解。通过将入射的一次电子及其感应的二次电子捕获在凹槽中来实现这种缓解。激光蚀刻样品的SEY取决于凹槽的几何特性和一次电子的入射角，即减小入射角会导致SEY减小。用2×10 ^-2 C mm ^-2的电子剂量对沟槽表面进行电子轰击它将最大SEY从1.15降低到0.98，这可能归因于Cu ₂ O和类似石墨的CC键的形成以及表面污染物的去除。