Hi, I have plans to make an electromagnet of about three Tesla. I don't know whether it might seem ignorant of me to wonder whether I could do this with a capacitor bank for the pulse and using a soft iron core 13mm diameter x 15cm long and some enamelled copper wire, (but I don't know what grade/resistance)? If this is gonna be unacheivable, can you let me know what's as close as possible that I can do with the given materials. Either way could you also tell me what thickness of the copper wire I'd need for either option. Thanks.
That is going to be a hugh electromagnet.
MRI machines typically use an electromagnet of 1 to 2 tesla, why don't you try to find some information about them. The electromagnets in MRI machines are designed to run continuously for a while.
A small core like that will probably saturate and you won't get a field high enough. You will probably have to go air core.
The action of the coil will reduce the peak current that you could get from the capacitor bank. Defibrillators really on that principal so that you don't burn the patient and also to stretch the electrical pulse that does the defibrillating.
When you choose your wire gauge, you should look up the fuse rating of each gauge of wire, at the same time, do some math to determine the peak current.
Shaun Shaun