[2P01-53] Poster Presentation

[2P27] Research of copper thermal spray coating for mitigating electron cloud

*Mu-Lee Yao¹, Yusuke Suetsugu¹, Kyo Shibata¹, Takuya Ishibashi¹, Hiromi Hisamatsu¹, Ken-ichi Kanazawa¹, Mitsuru Shirai¹, Shinji Terui¹ (1. High Energy Accelerator Research Organization)

To mitigate the electron cloud effect (ECE), we used a commercial method called “thermal spray” to create a rough surface with a low secondary electron yield (SEY) and investigated its suitability for accelerators. First, to the copper thermal spray (T.S.)-coated small samples, we measured their SEY profile, roughness parameters, surface composition, outgassing rate, adhesive strength, impedance, and dust generation rate. Next, an aluminum beam pipe with an optimized T.S. coating was produced and installed in the positron ring of SuperKEKB. We measured the electron density in the beam pipe and tried to interpret its behavior via simulations. The lowest δ_max of the T.S. coating reached ≈ 0.7 after conditioning. The measured electron densities of the T.S.-coated beam pipe were comparable with the TiN-coated one. Thus, the T.S. coating can be considered a candidate technology for reducing ECE, though room for improvement remains, such as relatively high levels of dust and impedance.