Procurement and installation of permanent magnets in SPIDER Grounded Grid and Extraction Grid PBS: 53.SI.A1

This note reports a summary on the activities carried out regarding the task PROJ_11 «Procurement and installation of permanent magnets in SPIDER Grounded Grid». The main goals of this task are to evaluate how good are the Criss-cross Deflection Effect (CCDE) compensations in SPIDER, based on the experimental data currently available, and to identify the optimized magnetic remanence of Grounded Grid (GG) magnets, in order to purchase one or more new sets of magnets if necessary. The activities regarded the interpretation of the available experimental results on the subject and comparisons with simulation activities. A final part of the note regards the procedures to be followed for removal, reinstallation and checks of magnets in GG and EG segments during SPIDER shutdown in 2022. The main outcome of the document regards the final decisions to be taken regarding the type and orientation of magnets to be installed in SPIDER GG and EG during the shutdown in 2022.