Magnetic Field Pulse

First question: can anyone help you?

Answer: Of course I/we can help you! Just not so much, yet! Read on to see why.

So, you are looking for a circuit or instrument to produce a high-intensity mag-field pulse in a relatively local area.

PROBLEM: You're not very specific in your requirements. I'm going to make this first part quick & lay it out straight for you, so don't take offense as I'm really only trying to help. Anyhow, "High-intensity" and "relatively local area" are not useful descriptive terms for, well, really anybody here. The problem is that "high intensity" to a microchip designer could mean a few tens to a couple hundred Gauss. Go ask a high-energy particle physicist about "high intensity" magnetic fields and he'll start talking about fields on the order of 10,000 Gauss MINIMUM (I believe that = 1 Tesla; Earth's B-field is a couple Gauss; for diamagnetic levitation you need maybe 20T or so, but that's beside the point, sorry.)

Back on topic: you do say "mm^2" which I take to mean "1x1mm" or "1mm^2" but again, your terminology is not incredibly useful since it still sounds somewhat ambiguous. "mm^2" just means square millimeters, the units- quantity is unspecified.

So, in conclusion: can I help you? Most likely, yes. However, you are going to have to divulge a lot more details than you have if you want to receive any sort of useful response. The more specific the question, the more specific the answer, up to a point (that said, you've still got quite a ways to go before reaching it- so be as specific as possible!) Are you able to tell us what this thing is for? The application dictates a lot of how the design is done. You say, "I would like the point source of the magnetic field to be as small as possible..." now I'm not gonna complain about lacking specifics here. What I am going to say is this: Firstly, a "point source" is defined as just that- a source of infinitesimally small size. So technically, any-intensity magnetic field's "point source" (i.e. an equivalent representation OF a real magnetic field AS point source(s) to simplify calculations or whatever) is small-as-can-be. That said, I know that you are looking for more tangible units of measure; more than construction advice that's really just a semantic/technical suggestion, but also an important concept.
Regarding the pulsed mags, before I outline a project progress/survey/plan: you can have a high field produced by a small source, but the distance it acts upon might not be enough. Or you might have a strong-enough field that's big enough, but can't turn on fast enough. Or the coil overheats. Or the batteries don't last long enough/can't put out enough power. What I'm trying to tell you is that you can almost always fulfill ONE or TWO or even several design parameters no sweat. The trick is getting everything to work TOGETHER well enough that the thing does what you want, doesn't fall apart, AND won't be the size of a Buick or cost a million bucks or whatever. Balance is the key, and often it can be very challenging (albeit rewarding) to achieve! Here is a sort of preliminary outline for your project. I don't know how far along you are thus far, but I hope this can help you decide if you have the motivation, desire, resources, and ability to forge ahead with & hopefully complete this project of yours. Try not to get overwhelmed by the amount of questions and such- a lot of them overlap, and not all will be necessary. Mostly it's a guide for yourself, but referencing it could help you ask better questions. Here goes nothin':

Operational Parameters: How does it function? (not only WHAT does it do but HOW does it do it: i.e. does it use changing B-flux as magnetic impulse, or a "chirp" square wave in which the central 'plateau' current is used as the magneto-motive force?)
--> Do I need to do more research to complete the project? Can I find & understand a resource to find my answers?
------>If no, can I get around this problem in another way? Have I exhausted all my resources of knowledge? Have I made a strong effort to learn on my own before asking others to do my work for me?
--------->If yes to 2nd & 3rd parts above: Now it's a good time to ask others for their input and ideas, once you've run into a wall. Asking in nonspecific terms for a lot of help before doing much of your own work is -VERY- unlikely to get you any answers because (1) People don't like to do entire projects for others unless they're getting paid somehow, and (2) When you don't include enough detail, anyone actually -wanting- to help won't know -how to- or where to begin or end, since there's nothing concrete to answer, really.

Necessary Field Strength: What is the minimum required B-field? Can this be reduced?
---->If yes, how? Demonstrate that this field strength is great enough to ensure RELIABLE operation, not just works-once-in-a-while
---->If no, are there other ways to reduce power consumption/heat buildup? Can the pulse-width be shortened? Can the number of activated matrix elements be reduced? Can structural components be used as heatsinks to reduce size/space/cost of any purpose-specific cooling?
****>Are there going to be problems with mutual inductance/reactance (aka the coils affecting each other via their outputted fields- could screw with many sensors)

Necessary duration of magnetic pulse(s): How long must each pulse last? What is the desired (or if there is no specific desire- what seems LIKELY, according to your calculations? Have you done any calculations? Are you able to?
---->If no, perhaps someone has already done something similar, or maybe even wrote simulation software that can accomplish what you need. Or if you're stumped, ask the community for help! Just don't ask the community to do it all for you...
---->If yes, go for it! Then show off your handiwork to us ; )

Duty cycle of electromagnets (what % of the time will they need to be "on" for)
------>What's the max power that each one will have to dissipate?
------>Will I need supplemental cooling (Heatsink, fan, Peltier jcn., combination, etc.)

Size, Shape, Weight and Portability: Regarding these, are there any restrictions??
----->If yes, comment and/or calculate the likely restriction (i.e. under 20lbs, must be battery powered, must look bitchin', has to fit into XYZ container, etc...)

Power Supply System: To supply the necessary pulses to your "magnetic matrix," you're probably going to want to use a power supply designed for that sort of thing; namely, you will likely have something that can switch power on/off at least as quickly as your calculated/estimated need; also it must supply the required current (Irq) continuously, but Irq applies to multiple units in the matrix: again this goes back to Duty Cycle. Also, there will be an Imax which must be available- this is a reserve energy bank, in the form of a capacitor, which allows for high peak power levels despite fairly low average power consumption. Enough about this for now- time to move on to another related topic:

Power Requirements: This means the amount of power that needs to go INTO the device (not the amount that one or even all of the magnets use; this is a composite amount, the amount that goes into the unit's own pulse-generating power supply AND any other component not directly getting its juice from the internal supply) Since the internal PS will have peak input/output power-handling ratings, this number (unlike most, so cherish it!) can be set as fixed. One thing down, about a billion to go... sometimes it seems like that, but just remember, every step counts, and even a small step still moves you towards where you're trying to be.

Here's a quick summary in case you fell asleep in the middle there: If you want good answers for your questions, please PLEASE include as much description and detail as possible without being excessively wordy (I'm a hypocrite, I know hehehe), so that people around here will know exactly what you're talking about, and hopefully be able to give you some satisfying answers. Specifically regarding your project: Refer to last sentence. I may be able to help quite a lot, but I can't help at all if I don't know what I'm supposed to be looking for or thinking about or designing or troubleshooting... yeah yeah I'm sure you get it by now. At least, I really hope so. But that's just how important good info is: I've repeated that a ton of times now heh. Anyway, think about my "planning/strategy guide" above; basically just think about your idea, if you think it's worth pursuing first-off (which you seem to think "Yes!" about, so there's 2 things down heh)... then consider if you have the time & resources to further the project... then consider my "guide" in more detail- come up with your own, similar questions for yourself to answer- believe me, it'll help clarify things in your mind... After this stage, you may be ready to start building, my friend! If not (don't rush it!!), then retrace your steps, find any problems; try to solve them. If you need help with something you're working on, ask us. If you need someone to do stuff for you, either pay someone to do it, or go somewhere else; I think I speak for most people around here when I say, "We don't need any skill-moochers around here!"

So, best of luck to you. Whatever your project is, the technical part of it appears possible, unless you need some kind of absurdly-high field strength and absurdly-small coils. So think about it for a while, where you want to take this, what you wanna do with it, THEN get back to me/us and hopefully you will find more people willing to help by offering more pointed questions- don't be TOO specific (by this I don't necessarily mean overly technical; I mean don't specify an obscure part or device or whatever, and then not explain its purpose or functioning when it's pretty clear most people won't know what you're talking about without looking it up. Try to provide all the necessary information in your post, like an engineering-forum-question Bento Box, if you are into Japanese food. Regardless, my apologies for rambling a bit. Let me know what you think of my "guide" as an aid to thinking/planning and if you have any other questions. 'Til then!