Beam radius 1mm
Halo radius shown an additional 5mm (6mm total from beam centres)
Elliptical vacuum chamber thickness 3mm, inner max half-height 8mm

The two pictures are at the same scale

B_r=1.07T in the mu=1 approximation, corresponding to B_r~1.12T because real mu=1.05, Shin-Etsu grade N36SH for example (H_cJ=21000 Oe, i.e. reverse flux of up to 2.1 Tesla without demagnetising)

QF (quad)
goal_quad = -42.54 T/m
GFR = 19mm
Inner radius of pieces = 28mm

BD (combined function)
goal_dipole = 0.486991622 T
goal_quad = 27.493 T/m
GFR = 12.5mm
Inner radius of pieces = 21.5mm