ZEPTO Dipoles Magnet Modelling Update Ben Shepherd 19 March 2015

AdderBoaCobra PythonSidewinderViper

Meeting with Vacuumschmelze Discussed various PM dipole designs Cobra (rotating PMs) – not favoured – Large torques (8 kNm) – Assembly would be difficult Possible to drill holes in PM (for supporting rods) Decided on VACODYM 764 TP – have B-H curve – NdFeB, B r = 1.37 T; H c = 1060 kA/m Maximum dimension for PM blocks: mm – Construct block from many smaller blocks (as before) Tolerance of 3%, 3° easily achievable

Fields in 3D Started modelling some options in 3D Field (in some cases) significantly lower – Reasons for this are not fully understood! – Generally better for H-magnets – Recovered (in some cases) for a 1.5m version

Comparison of models CodenameModelPicture Force horizontal vertical Stroke Overall size W x H [m] PM area Field range (3D) 0.5m1.5m Adder kN155 mm0.75 x m² T Large forces; Very tall; H magnet version; Rectangular PMs Boa kN158 kN180 mm1.37 x m² T T Radial PMs; H magnet version; Field quality less certain because move steel close in? (especially true for C- magnet versions); Curved poles could be difficult. Python kN max 1.8 kN (stress) 390 mm1.14 x m² T T Small forces; Wide ; Large stroke; Learn lessons from low strength quad?; Rectangular PMs Sidewinder kN123 kN500 mm1.24 x m² T T Motion system could be difficult; Tuning range not demonstrated yet; Large stroke; Small force in motion direction; Rectangular PMs; Biggest cross section Viper mm0.96 x m² T T Small forces; Wide ; Learn lessons from low strength quad?; Rectangular PMs

Conclusions Currently Python is the preferred option – Reasonable size – Forces are OK – Similar to low-strength quadrupole – C-magnet But field will be lower for 0.5m prototype