Detailed characterization of SARS-CoV-2-specific T and B cells after infection or heterologous vaccination

: The formation of a robust long-term antigen (Ag)-specific memory, both humoral and cell-mediated, is created following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection or vaccination. Here, by using polychromatic flow cytometry and complex data analyses, we deeply investigated the magnitude, phenotype, and functionality of SARS-CoV-2-specific immune memory in two groups of healthy subjects after heterologous vaccination compared to a group of subjects who recovered from SARS-CoV-2 infection. We find that coronavirus disease 2019 (COVID-19) recovered patients show different long-term immunological profiles compared to those of donors who had been vaccinated with three doses. Vaccinated individuals display a skewed T helper (Th)1 Ag-specific T cell polarization and a higher percentage of Ag-specific and activated memory B cells expressing immunoglobulin (Ig)G compared to those of patients who recovered from severe COVID-19. Different polyfunctional properties characterize the two groups: recovered individuals show higher percentages of CD4+ T cells producing one or two cytokines simultaneously, while the vaccinated are distinguished by highly polyfunctional populations able to release four molecules, namely, CD107a, interferon (IFN)-γ, tumor necrosis factor (TNF), and interleukin (IL)-2. These data suggest that functional and phenotypic properties of SARS-CoV-2 adaptive immunity differ in recovered COVID-19 individuals and vaccinated ones

Design of a 4 tesla superconducting dipole magnet for CERN experimental North-Area

The object of this dissertation is the design of a 4 T superconducting dipole magnet. This magnet will be used for testing of future detectors instrumentation and it has been envisioned to replace or complement the outdated systems available at the North Experimental Area at CERN. The magnetic design has been performed via Finite Element Analysis. A FE model is prepared in ANSYS Maxwell 3D for modeling the magnetic field of such large magnets, this model was validated using the geometry and operating parameters of an existing magnet at CERN: the H8 Morpurgo dipole. The magnetic design consists in the optimization of the coil geometry for matching the requirements in terms of central magnetic field, peak field in the conductor and stray field. Two different geometries are investigated for the magnet system: split saddle shape and flared-end geometry. The most favorable one is chosen to proceed with the windings cable design. To conclude, a support structure is designed to handle Lorentz forces acting of the magnet cold mass. The mechanical simulation is performed via Finite Element Analysis using ANSYS Static Structural

Measurement of the SMH16.3 Magnetic Septa

The fast extraction septum PE.SMH16 is used to deflect protons and ions for the extraction transfer line TT2 from SS16 [1] [2]. Within the task of completing the impedance model of the PS, an impedance analysis of this existing machine element was required, however, since this is a long-existing element, only paper documentation of the septa is available. Due to the envisaged change of the PS layout which would lead to a replacement of the SMH16 [3] with an eddy current septa, a full modeling of this geometry for detailed EM-analysis and calculation of beam impedance was omitted. Instead, wire measurements have been carried out on the PE.SMH16.3 tank which shall provide sufficient information of the existing impedance contribution. As of today, four SMH16 exist at CERN of which one is installed in the PS in the location SS16, whereas the others remain as spares

Beam Coupling Impedance of the Main Extraction Kickers in the CERN PS

In view of the High Luminosity (HL) upgrade of the LHC, the beam intensity must be doubled in the injector chain. To perform reliable beam dynamics simulations, the beam coupling impedance in the injectors, such as the Proton Synchrotron (PS), must be followed closely by including all contributing elements into the impedance model. The existing kicker magnets of the PS had been optimized for large kick strength and short rise/fall times, but not necessarily to minimise beam coupling impedance. Hence, unwanted beam induced voltage can build up in their electrical circuits, with an impact on the beam. The beam coupling impedances of the two main kicker magnets used for the fast extraction from PS, the KFA71 and KFA79, are extensively characterized in this study. In particular, electromagnetic simulation results for the longitudinal and transverse coupling impedance are shown. The critical impedance contributions are identified, and their effect on beam stability is discussed. Moreover, the impact of the cable terminations on the electromagnetic field pattern and possible mitigation techniques are presented, providing a complete impedance evaluation of the entire kicker installation

Strategic R&D Programme on Technologies for Future Experiments - Annual Report 2020

This report summarises the activities and achievements of the strategic R&D programme on technologies for future experiments in the year 2020

Strategic R&D Programme on Technologies for Future Experiments - Annual Report 2021

This report summarises the activities and main achievements of the CERN strategic R&D programme on technologies for future experiments during the year 2021

Annual Report 2023 and Phase-I Closeout

This report summarises the activities of the CERN strategic R&D programme on technologies for future experiments during the year 2023, and highlights the achievements of the programme during its first phase 2020-2023