Super-NaNu is a proposed neutrino experiment as part of the SHADOWS proposal for the high intensity facility ECN3 in CERN's North Area. It aims to detect neutrino interactions downstream of a beam-dump that is penetrated with a 400 GeV high intensity proton beam from the SPS. The experiment would run in parallel to the HIKE and SHADOWS experiments, taking data with an emulsion detector. Simulations show that various combinations of muon backgrounds pose the major limiting component for NaNu operation. As muons will leave tracks in the emulsion detector, their flux at the detector location is directly correlated to the frequency of emulation exchange and therefore with the cost of the experiment. Finding ways of mitigating the muon background as much as possible is therefore essential. In this paper, we present a possible mitigation strategy for muon backgrounds.

Super-NaNu is a proposed neutrino experiment as part of the SHADOWS proposal for the high intensity facility ECN3 in CERN's North Area. It aims to detect neutrino interactions downstream of a beam-dump that is penetrated with a 400 GeV high intensity proton beam from the SPS. The experiment would run in parallel to the HIKE and SHADOWS experiments, taking data with an emulsion detector. Simulations show that various combinations of muon backgrounds pose the major limiting component for NaNu operation. As muons will leave tracks in the emulsion detector, their flux at the detector location is directly correlated to the frequency of emulation exchange and therefore with the cost of the experiment. Finding ways of mitigating the muon background as much as possible is therefore essential. In this paper, we present a possible mitigation strategy for muon backgrounds.

400 GeV protons extracted from the CERN SPS are transported to the T4 target via the TT20 transfer line. The P42 beamline then transports the protons that did not interact in the T4 target to the T10 target. During operation in 2021 and 2022, higher than expected beam losses were measured, in addition to an increased beam spot size that had previously been observed. It was suspected that the optics between TT24 and P42 might not be well matched but due to a lack of instrumentation this was not confirmed. The recent installation of additional beam profile monitors (BSG) in the P42 beamline has allowed the present optics to be evaluated for the first time. In addition, magnet response functions have been measured and updated. A kick response study was performed using corrector dipoles to kick the beam with the subsequent displacement measured on the BSGs. The dependence between the kick and the beam position was used to fit a MADX optics model of TT24 and P42. Quadrupole scans were then performed to determine the initial conditions of the model. These results are presented in this paper.