The Joint Accelerator Conferences Website (JACoW) is an international collaboration that publishes the proceedings of accelerator conferences held around the world.
TY - CONF AU - Feng, H.Q. AU - Baptiste, K.M. AU - De Santis, S. AU - Huang, W.-H. AU - Li, D. AU - Liu, Z.N. AU - Luo, T.H. AU - Tang, C.-X. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Design Study on Higher Harmonic Cavity for ALS-U J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The ALS upgrade (ALS-U) to a diffraction-limited light source  depends on the ability to lengthen the stored bunches to limit the emittance growth and increase the beam life time. Higher harmonic cavities (HHCs), also known as Landau cavities, have been proposed to in-crease beam lifetime and Landau damping by lengthen-ing the bunch. We present an optimized 1.5 GHz normal conducting HHC design for the ALS-U with a supercon-ducting-like geometry using multi-objective genetic algorithm (MOGA) for lower R/Q. The optimization goal is to reach the required shunt impedance while maintain-ing a relatively high Q value of the cavities. To minimize the coupled bunch instabilities, higher-order mode (HOM) of the HHC as well as corresponding impedance are explored and characterized. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3011 EP - 3013 KW - cavity KW - impedance KW - higher-order-mode KW - simulation KW - wakefield DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPRB081 UR - http://jacow.org/ipac2019/papers/weprb081.pdf ER -