My first post here - great forum!

I am building an electromagnet for a magneto-optical study, I am hoping someone can point me in the right direction

My specs are fairly straightforward:

C shape electromagnet with a 5cm or so gap

varaiable 0 - 150 Gauss max field

I know the core should be 1010 or soft FE, can someone point me toward how to calculate the # of terms and the expected flux? I can't seem to find any good resources on this topic (except in this forum). Any good books on the topic?

Thank you in advance,

Mike