The Joint Accelerator Conferences Website (JACoW) is an international collaboration that publishes the proceedings of accelerator conferences held around the world.
TY - CONF AU - Ohmi, K. AU - Funakoshi, Y. AU - Hirosawa, K. AU - Koiso, H. AU - Morita, A. AU - Ohnishi, Y. AU - Zhou, D. ED - Li, Ying-ying ED - Li, Lu ED - Schaa, Volker RW TI - Optics Aberration at IP and Beam-beam Effects J2 - Proc. of eeFACT2018, Hong Kong, China, 24-27 September 2018 CY - Hong Kong, China T2 - ICFA ABDW on High Luminosity Circular e$^+$e$^-$ Colliders T3 - 62 LA - english AB - Collision in SuperKEKB phase II commissioning has started in April 2018. Luminosity was lower than the geomterical value even in very low bunch current. Linear x-y coupling at IP caused by skew of QCS was conjectured as error source. x-y coupling correction using skew corrector of QCS resulted in luminosity recover of 2 times. After the QCS skew correction, luminosity is still limited at relatively low bunch current. Nonlinear x-y coupling at IP is conjectured as a source of the luminosity limitation. We discuss effects of linear and nonlinear x-y coupling at IP on the beam-beam performance. PB - JACoW Publishing CP - Geneva, Switzerland SP - 66 EP - 70 KW - luminosity KW - coupling KW - emittance KW - MMI KW - optics DA - 2019/04 PY - 2019 SN - 978-3-95450-216-5 DO - DOI: 10.18429/JACoW-eeFACT2018-TUOBB01 UR - http://jacow.org/eefact2018/papers/tuobb01.pdf ER -