The Swiss Light Source (SLS) has been operational now for nearly two decades. In this period, it has spearheaded groundbreaking research in biomedicine, engineering and the natural sciences, thanks in large part to the excellent performance of the underpinning electron accelerator and storage ring complex. In addition, it has led the world in industrial exploitation, particularly by the pharmaceutical sector, and spawned numerous new companies, including one of the most successful Swiss technology spinoffs, Dectris. For much of this time, the SLS was a benchmark with regards to how closely its performance matched the theoretical limits deﬁned by its machine parameters. However, with the advent of the next generation of synchrotron light sources, called diffraction-limited storage-rings (DLSRs), that yield an emittance and brightness improved by up to two orders of magnitude, it has become imperative to upgrade the SLS (called SLS 2.0) in like manner. It is planned to upgrade the machine in 2023/2024 with a planned improvement in performance of up to a factor of 40, and return to regular user operation in 2025.
In December 2020 the Swiss parliament approved the Swiss Dispatch on Promotion of Education, Research and Innovation (ERI) for 2021 to 2024 which includes funding for the planned SLS 2.0 upgrade. The new machine will lead to significantly increased brightness, thus providing a firm basis for keeping the SLS and its beamlines state-of-the-art for the decades to come. The TOMCAT crew is very excited that the TOMCAT 2.0 plans (deployment of the S- and I-TOMCAT branches, see SLS 2.0 CDR, p. 353ff) have been included in the Phase-I beamline upgrade portfolio. These beamlines will receive first light right after the commissioning of the SLS 2.0 machine around mid 2025. A first milestone towards this goal has just been achieved, with the successful installation of the S-TOMCAT optics hutch during W1 of 2021. The TOMCAT scientific and technical staff would like to thank Mr. Nolte and his Innospec crew for delivering perfectly on schedule.