  We present the design of our iron-core electromagnet for BEC, and how to
solve the specific experimental problems raised by this technique. After
presenting the experimental set-up, we address the interruption of runaway
evaporative cooling when the Zeeman effect is not linear. We present the ways
to circumvent this problem, use of multiple RF frequencies, sympathetic cooling
and show some applications of these high magnetic fields (cavity coupling, high
confinement).
