“…The instrument, described in detail by Mazza et al (2012) and Meyer et al (2023), was commissioned in 2018 (Meyer et al, 2023) and the results of the first successful user experiments have been published (Kastirke et al, 2020a,b;Eichmann et al, 2020;Mazza et al, 2020;LaForge et al, 2021;Jahnke et al, 2021;Li et al, 2021Li et al, , 2022aBoll et al, 2022;Feinberg et al, 2022). Experiments at the SQS instrument exploit the intense, short and coherent X-ray pulses for nonlinear phenomena studies (Mazza et al, 2020;Eichmann et al, 2020;LaForge et al, 2021;Boll et al, 2022), for time-resolved experiments following dynamical processes on the femtosecond timescale (Kastirke et al, 2020b;Jahnke et al, 2021;Grychtol et al, 2021;Rivas et al, 2022) and for investigations using coherent scattering techniques (Ekeberg et al, 2022;Feinberg et al, 2022). This paper is dedicated to the description of the X-ray beam transport system in use during the commissioning phase and the first three user runs until the beginning of 2020, and reports on its performance, evaluated from the results obtained during its commissioning.…”