47 Conrad, Thorsten Aulenbacher, Kurt Barth, Winfried Basten, Markus Busch, Marco Dziuba, Florian Gettmann, Viktor Heilmann, Manuel Kürzeder, Thorsten Lauber, Simon List, Julian Miski-Oglu, Maksym Podlech, Holger Rubin, Anna Schnase, Alexander Schwarz, Malte Yaramyshev, Stepan LIN MDI PSU LRF Cavity Designs for the CH3 to CH11 of the Superconducting Heavy Ion Accelerator HELIAC Proceedings of the 19th International Conference on RF Superconductivity The 19th International Conference on RF Superconductivity JACoW Publishing, Geneva, Switzerland Dresden, Germany 10.18429/JACOW-SRF2019-TUP005 English 396-398 In collaboration of GSI, HIM and Goethe University Frankfurt new designs for the CH-DTL cavities of the proposed Helmholtz Linear Accelerator (HELIAC) are developed. The cw-mode operated linac with a final energy of 7.3 MeV/u is intended for various experiments, especially with heavy ions at energies near the coulomb barrier. Currently twelve superconducting CH-cavities are considered which will be split into four different cryostats. Each cavity will be equipped with dynamic bellow tuners. After successful beam tests with CH⁰ as well as last surface preparations and ongoing rf tests with CH1 and CH2, CH3 to CH11 will be designed. Based on the successful test results, individual optimizations are carried out on the cavity design. Attention was paid to reduce production costs, for example by keeping the cavity diameter in each cryostat constant despite varying particle velocities and gap numbers. In addition to reaching the resonance frequency of 216.816 MHz and the influence of the bellow tuners on the frequency, the mechanical stability of the bellow tuners, the thermal effects on the cavity and the measures to mitigate secondary electron emission are investigated. "Published by JACoW Publishing under the terms of the Creative Commons Attribution 3.0 International license. Any further distribution of this work must maintain attribution to the author(s), the published article's title, publisher, and DOI." ; Proceedings of the 19th International Conference on RF Superconductivity ; Contribution to a conference proceedings 2019 2019-06-30 - 2019-07-05 GSI-2019-01089 2019-06-30 - 2019-07-05 2019 https://repository.gsi.de/record/220295 https://doi.org/10.18429/JACOW-SRF2019-TUP005