Koay, H.W. Fukuda, M. Kanda, H. Nakao, M. Yorita, T. JACoW Publishing Geneva, Switzerland 978-3-95450-205-9 10.18429/JACoW-Cyclotrons2019-WEC01 English 279-283 WEC01 cyclotron injection space-charge extraction neutron Contribution to a conference proceedings 2020 2020-06 https://doi.org/10.18429/JACoW-Cyclotrons2019-WEC01 http://jacow.org/cyclotrons2019/papers/wec01.pdf A compact high-current accelerator is highly desirable for short and effective Boron Neutron Capture Therapy (BNCT) as well as radioisotopes production in a hospital environment. In accordance with this, a compact high-temperature superconducting skeleton cyclotron (HTS-SC) was proposed. HTS-SC is an air-core K-80 cyclotron with a relatively small extraction radius of 40 cm for a 50 MeV H⁺ and 40 MeV D⁺ beam. Owing to its compactness, a relatively high central magnetic field (>2.4 T) remains as a significant challenge for high current injection. This work describes a preliminary study of the injection using a spiral inflector and the central region design of the HTS-SC. Besides, the transverse beam dynamics are also discussed in order to investigate the upper limit of injection current.