Recent content by Nergus

Hi bz2005, Thanks very much for the 3D simulation back-up! A package that expensive has waaay more 'cred' than a free 2D package; however highly thought of! I'm hoping to learn a lot more about the mechanics of the Magscan, starting next week. It's certainly true that the vector sum peaks are...

Hi IRstuff, Unfortunately, Magscan consistent with Magscan has never been a problem. I really do get the N magnets = N peaks thing, it has a kind of 'get what you pay for' simplicity and natural justice. It's the FEMM (N-1) peaks that demands the burden of proof. Yet instinctively, FEMM is...

OK, here are the Magscan outputs for the 3/8" square x 7/8" long N38 magnet with the North face up. Next are 2 magnets side by side, N then S up... What was the question again? Oh yes! Are we all agreed why it looks nothing like the FEMM simulations attached last time...

Hi Art, The Magscan is a flat bed with a half-metre square active scan area. The 3-axis probe is on stepper-motor driven slides for the X and Y axis movement - which is a raster scan under software control. The Z-axis 'control' is manual probe height adjustment via a micrometer. The most useful...

Don't worry about it, I'm going to see Prof D next week, he knows all about this stuff! Alan

Hi IRstuff, Magnet size - 9mm is what's required, 3/8" is what I could buy 'off-the-shelf' to try on the Magscan. The intention was to back-up the simulation results... not what happened! What I'm saying is, if you Magscan close to a big block magnet (100mm, like the previous attachment) with...

Hmmm... I can see that in my last posting (gone midnight here) I lost track of the point I was trying to make, which was in essence agreeing with MJR2 (thanks). If you have a relatively big hall probe passing over a small magnet, you get a single big rise in output. If you look at a big block...

Thanks for the postings! MJR2 - I'm trying to move the nanoparticles. The force on them is proportional to the absolute field strength and the magnetic gradient. FEMM says both quantities peak over the N-S join, hence 12 peaks for 13 magnets. I will try to find out the physical dimensions of...

Thanks Mike, I sort of see what you're getting at. The IBI plot from FEMM is the instantaneous magnitude of the vector quantity with no directional information. The vector sum output from the Magscan is.... I'm not entirely sure what? I can imagine the X-axis hall detector looks more like...

I'm open to being told what I've done wrong here! Quite new to FEMM and self-taught - by an idiot. I've modelled a static array of 13-off 3/8" NIB cube-magnets in N52, arranged alternate North and South at the top. An analysis of flux density at a couple of mm above this array shows 12 'lobes'...