Possible future upgrades of the direct-geometry chopper spectrometer 4SEASONSRyoichi Kajimoto, Mitsutaka Nakamura, Kazuya Kamazawa, Yasuhiro Inamura, Kazuki Iida, Kazuhiko Ikeuchi and Motoyuki IshikadoEPJ Web Conf., 272 (2022) 02007DOI: https://doi.org/10.1051/epjconf/202227202007