Yes, an ordinary copper electromagnet would "work", but the energy requirement would be huge, and the resource requirement (all that Copper or Silver) would be huge, and the field would nto be as stable as the persistent field in a closed-loop s/c magnet so the image would be worse: so forget cheap MRI scans at "only" a few hundred $$..

There are MRI machines made using a 3 tonne permanent magnet - which is "low field" and OK-ish for wrists and ankles.

Yes, BSCCO and YBCO and all the High Temperature Superconductors can't do persistent joints. This means that you need to put the electric current into them constantly instead of just closing the loop at startup and letting the current run all by itself.

This isn't a problem about energy use, it's an issue about stability: a persistent current in an s/c magnet is incredibly stable, so you get a nice sharp MRI image.

There is one company making MgB2 MRI machines, and they run them at about 10K so far as I remember, using direct conduction instead of imersing them in a cryogenic liquid. You want to run the machine as cold as you can because then the current-carrying capacity of the s/c goes up.

Learn some physics. Then you may understand this one.

In Japan, Helium has been more expensive for a while. So the major MRI manufacturers already produce recondensing He MRI machines for that market. There is still some leakage of course.

While this is good news for the one company in the world making MgB2 MRI machines (in Italy)... [High Temperature superconductrors don't do persistent magnets, so they can't be used], there is a much more important problem. .. any physicist / materials engineer can see that that the resource depletion problem for Helium is of a different order than for fuels, mercury, zinc, nickel etc. etc. There is absolutely nothing, nothing at all in this universe, that liquifies at 5K or below.

It is truly unique, and while material substitution can be expected for some applications (cf. MRI above), there are some where it is not just technology, but p*hysics*, which is telling us that there are no substitutes. IR detectors for astronomy have to be cooled as cool as you can get: and while you could use direct conduction and a fridge, with a liquid Hydrogen shield, that makes the vibation problem harder.

Having said that, it is perhaps just a matter of price. In principle we can extract Helium from granite: it would just be very, very, very expensive. In a couple of hundred years it might be cheaper to make it from seawater Lithium using a handy fusion reactor (with MgB2 magnets, of course), or from Jupiter's atmosphere...

Yes . GraphViz and dot are magic. You still have to read the code of course, but this gives you the map to guide your reading. The pictures are usefully impressive for your new bosses to show that you are making progress too. Really useful for showing up that nuggt of code that gets called from everywhere. http://www.graphviz.org/Gallery/directed/profile.html