Counter Force Detonators

[me234]

So anyway, I was just sitting around the other morning, daydreaming about those things we all daydream about. In particular that morning, I was contemplating insensitive HE’s and how shoving, with tremendous force and pressure and violence of course, a second det. into the charge helps to get it going. Now suddenly a thought sprang forth unto my conscience (yes that is my one for the rest of the year).

The thought that occurred was along the lines of a picture. I pictured these two dets sitting side by side a few centimetres apart in the main charge. However the picture in my mind of this thing going off involved the 2 dets being initiated simultaneously and their collective effects acting just like the “counter force charges” (described in “CIA Improvised Sabotage Devices” from Desert Publications). This ‘counter force’ effect is said to roughly halve the amount of explosives needed for any given task.

So here I was faced with the reality that suddenly, if using the counter force charge principle of the positive addition of wave amplitudes, one can use significantly less primary to accomplish high order initiation in a base charge or what have you. But the problem is that most people go with overkill whenever possible for detonators, so needing less primary doesn’t really matter if you can afford to use 20g APAN as a detonator.

So obviously we are left with the conclusion that unless
1- one is desperately short of primary explosives; or
2- one has explosives that can detonate in extremely small amounts
my entire post is worthless.

BUT, with the advent of azo-clathrates etc. one does indeed have primary explosives that detonate in extremely small amounts.
The picture in my mind goes something along the lines of two miniature discs each consisting of minimal amounts of azo-clathrate (tailored to minimize deflagration – detonation distance) perfectly parallel to each other at a distance that would probably have to be determined by calculations and experimentation.

These two discs could be constructed by tightly pressing with the use of a small amount of added phlegmatizer to help maintain the charge shape. These 2 discs could then be inserted into a liquefied low melting point explosive which would then be slowly solidified to prevent cracks and warping from occurring. Even better would be its use in a liquid explosive, something that needs a fair kick in the ass to get going, e.g. nitromethane; various nitro-glycerine mixtures that tend to detonate at low order velocities.

Basically I’m hoping that the 2 discs would detonate and send their waves directly at each other. These waves would then undergo constructive interference and the increased amplitude, representative of the wave energies, would provide sufficient energy to excite the base charge molecules over and above the activation energy required to cause detonation.

Well, that’s how it SHOULD go, theoretically and in my imagination of course.
Practically, I’m not sure exactly how one would precision cast milligram quantities of a primary explosive to exact dimensions, and then fix them to some sort of structure that would hold them in place.

The initiation of the discs however, would be a major obstacle. I was thinking, quite unrealistically, about a capillary tube packed with azo-clathrate or nitrocellulose fibres that could be initiated in the main housing of the detonator (the structure holding the discs in place) and they would direct a flame or shockwave to the centre of the cast discs.

Even if this scale of miniaturization is completely impossible (but nothing’s impossible) the application of counter force based detonators could still prove useful for IHE’s in small devices, e.g. submunitions.

The only idea that comes to mind about casting small amounts of primary is by using the apparatus used to produce KBr discs for Infrared spectroscopy. However, compressing primary explosives by ~10 tons of weight on top of the primary charge doesn’t seem like a whole lot of fun to me.

I figure if one could come up with some way of actually making these damned things, and if one could prove its industrial applications, then one could definitely get a patent for this. But now that I’ve posted this somewhat unlikely idea, no patent, and therefore no monopoly is possible for this idea, it is now completely free to the world.

However, even if my idea turns out to be a load of crap, it’s still given me hours of imaginative entertainment.

So, please, opinions everyone, particularly Rosco Bodine and others with experience in azo-clathrates and the like or counter force charges.

I’ve attached a diagram of what I’m hoping the device would look like.

[me234]

So anyway, I was just sitting around the other morning, daydreaming about those things we all daydream about. In particular that morning, I was contemplating insensitive HE’s and how shoving, with tremendous force and pressure and violence of course, a second det. into the charge helps to get it going. Now suddenly a thought sprang forth unto my conscience (yes that is my one for the rest of the year).

The thought that occurred was along the lines of a picture. I pictured these two dets sitting side by side a few centimetres apart in the main charge. However the picture in my mind of this thing going off involved the 2 dets being initiated simultaneously and their collective effects acting just like the “counter force charges” (described in “CIA Improvised Sabotage Devices” from Desert Publications). This ‘counter force’ effect is said to roughly halve the amount of explosives needed for any given task.

So here I was faced with the reality that suddenly, if using the counter force charge principle of the positive addition of wave amplitudes, one can use significantly less primary to accomplish high order initiation in a base charge or what have you. But the problem is that most people go with overkill whenever possible for detonators, so needing less primary doesn’t really matter if you can afford to use 20g APAN as a detonator.

So obviously we are left with the conclusion that unless
1- one is desperately short of primary explosives; or
2- one has explosives that can detonate in extremely small amounts
my entire post is worthless.

BUT, with the advent of azo-clathrates etc. one does indeed have primary explosives that detonate in extremely small amounts.
The picture in my mind goes something along the lines of two miniature discs each consisting of minimal amounts of azo-clathrate (tailored to minimize deflagration – detonation distance) perfectly parallel to each other at a distance that would probably have to be determined by calculations and experimentation.

These two discs could be constructed by tightly pressing with the use of a small amount of added phlegmatizer to help maintain the charge shape. These 2 discs could then be inserted into a liquefied low melting point explosive which would then be slowly solidified to prevent cracks and warping from occurring. Even better would be its use in a liquid explosive, something that needs a fair kick in the ass to get going, e.g. nitromethane; various nitro-glycerine mixtures that tend to detonate at low order velocities.

Basically I’m hoping that the 2 discs would detonate and send their waves directly at each other. These waves would then undergo constructive interference and the increased amplitude, representative of the wave energies, would provide sufficient energy to excite the base charge molecules over and above the activation energy required to cause detonation.

Well, that’s how it SHOULD go, theoretically and in my imagination of course.
Practically, I’m not sure exactly how one would precision cast milligram quantities of a primary explosive to exact dimensions, and then fix them to some sort of structure that would hold them in place.

The initiation of the discs however, would be a major obstacle. I was thinking, quite unrealistically, about a capillary tube packed with azo-clathrate or nitrocellulose fibres that could be initiated in the main housing of the detonator (the structure holding the discs in place) and they would direct a flame or shockwave to the centre of the cast discs.

Even if this scale of miniaturization is completely impossible (but nothing’s impossible) the application of counter force based detonators could still prove useful for IHE’s in small devices, e.g. submunitions.

The only idea that comes to mind about casting small amounts of primary is by using the apparatus used to produce KBr discs for Infrared spectroscopy. However, compressing primary explosives by ~10 tons of weight on top of the primary charge doesn’t seem like a whole lot of fun to me.

I figure if one could come up with some way of actually making these damned things, and if one could prove its industrial applications, then one could definitely get a patent for this. But now that I’ve posted this somewhat unlikely idea, no patent, and therefore no monopoly is possible for this idea, it is now completely free to the world.

However, even if my idea turns out to be a load of crap, it’s still given me hours of imaginative entertainment.

So, please, opinions everyone, particularly Rosco Bodine and others with experience in azo-clathrates and the like or counter force charges.

I’ve attached a diagram of what I’m hoping the device would look like.

[Jacks Complete]

The pictures not approved yet, but this would seem to be a shaped charge effect in the twin detonators, wouldn't it?

If so, then cast the det plug as a tiny shaped charge, initiated at the top just like normal.

It might need a bottleneck, choke or something to ensure the timing is right, though, as the VoD is very high, and getting an additive wavefront would otherwise be very hard on a mm scale.

Something that looks like:
<code>
\ /
| |
&nbsp;Y
&nbsp;|
|||
</code>
with initiation at the bottom, a choke, then two prongs, which go up at the same instant, causing a Monroe effect between them, and high order detonation.

Is this the kind of thing you were thinking?

[Jacks Complete]

The pictures not approved yet, but this would seem to be a shaped charge effect in the twin detonators, wouldn't it?

If so, then cast the det plug as a tiny shaped charge, initiated at the top just like normal.

It might need a bottleneck, choke or something to ensure the timing is right, though, as the VoD is very high, and getting an additive wavefront would otherwise be very hard on a mm scale.

Something that looks like:
<code>
\ /
| |
&nbsp;Y
&nbsp;|
|||
</code>
with initiation at the bottom, a choke, then two prongs, which go up at the same instant, causing a Monroe effect between them, and high order detonation.

Is this the kind of thing you were thinking?

[nbk2000]

Computer drawn graphics should be saved in .GIF format. Much more compact and no jaggies. ;)

Using opposed detonators is a technique being used for selectable munitions. That is, warheads that can be used in either EFP or SC attacks, with the ability to vary the shaping of the resulting penetrators or jets by varying the timing between the detonators initiation.

But, since your initiation points are so close together, they should act essentially as a single detonator.

I think that 'counter-force' detonators may indeed work as you think, creating an increased pressure for the same charge weight.

[nbk2000]

Computer drawn graphics should be saved in .GIF format. Much more compact and no jaggies. ;)

Using opposed detonators is a technique being used for selectable munitions. That is, warheads that can be used in either EFP or SC attacks, with the ability to vary the shaping of the resulting penetrators or jets by varying the timing between the detonators initiation.

But, since your initiation points are so close together, they should act essentially as a single detonator.

I think that 'counter-force' detonators may indeed work as you think, creating an increased pressure for the same charge weight.

[mil&co]

The initiation of the discs however, would be a major obstacle.
What about EBW's?, thats what they were origionally invented for: Detonating the plutonium-propellant charges at exactly the same time.

Having that said, you could even go for PETN as replacement for the azo-clathrates, or moldable medium-sensitive HE's, making it easier to shape the disks.

[mil&co]

The initiation of the discs however, would be a major obstacle.
What about EBW's?, thats what they were origionally invented for: Detonating the plutonium-propellant charges at exactly the same time.

Having that said, you could even go for PETN as replacement for the azo-clathrates, or moldable medium-sensitive HE's, making it easier to shape the disks.

[me234]

Jack's, that's similar to the idea I was thinking about. Hopefully the pic will clear up any confusion. But now that you mention it a miniature shaped charge (hollow charge) should also create a region of higher than normal energy along the SC's jet's length. This increased peak energy could also have that same effect of requiring less primary.

NBK, I was thinking along the lines of making these so that less primary would be needed for the same effect. I'm glad that you think it'll work. In sub-munitions like cluster bombs, I was contemplating quite small bomblets, where a conventional detonator would waste valuable space where more secondary could be squeezed in.

[me234]

Jack's, that's similar to the idea I was thinking about. Hopefully the pic will clear up any confusion. But now that you mention it a miniature shaped charge (hollow charge) should also create a region of higher than normal energy along the SC's jet's length. This increased peak energy could also have that same effect of requiring less primary.

NBK, I was thinking along the lines of making these so that less primary would be needed for the same effect. I'm glad that you think it'll work. In sub-munitions like cluster bombs, I was contemplating quite small bomblets, where a conventional detonator would waste valuable space where more secondary could be squeezed in.

[Jetex Kid]

How wide are the disks? One cm? Two cm?

How simultaneously do the disks have to explode to be synergistic? If the disks are initiated in the center, would one disk ¼ consumed just as the other is beginning, be acceptable timing?

If so, assuming that the detonation velocity is 5,000 m/s, and the disks are 2 cm in diameter, and one disk can detonate 0.5 cm before the other disk begins, then the difference in detonation response times must be one microsecond or less!

I’m not talking electrical timing, but *variations* in time between the onset of current and detonation by the detonator. If one disk detonates in response to the current in 10 usec and the other in 31, it sure won’t work.

I will not write reams to provide partial justification for my belief that consistency of detonation responses with 1 usec variability is not realistic for us Forumites.

However, connecting the two halves by an explosive bridge initiated (only once!) in the middle might solve this problem. Then, however, the bridge is exploding in the midst of the secondary explosive, but it might work anyway.

[Jetex Kid]

How wide are the disks? One cm? Two cm?

How simultaneously do the disks have to explode to be synergistic? If the disks are initiated in the center, would one disk ¼ consumed just as the other is beginning, be acceptable timing?

If so, assuming that the detonation velocity is 5,000 m/s, and the disks are 2 cm in diameter, and one disk can detonate 0.5 cm before the other disk begins, then the difference in detonation response times must be one microsecond or less!

I’m not talking electrical timing, but *variations* in time between the onset of current and detonation by the detonator. If one disk detonates in response to the current in 10 usec and the other in 31, it sure won’t work.

I will not write reams to provide partial justification for my belief that consistency of detonation responses with 1 usec variability is not realistic for us Forumites.

However, connecting the two halves by an explosive bridge initiated (only once!) in the middle might solve this problem. Then, however, the bridge is exploding in the midst of the secondary explosive, but it might work anyway.

[Jacks Complete]

Jetex Kid, that was the point of my design.

The initiation point is outside the body of the charge, and the shockwave travels downwards, through a narrow constriction, then grows again.

Optically or physically it would be a pinhole, and as the explosion would then appear to radiate from that point, microsecond timings would be consistently achieved. This would be very like your bridge idea, but could be made much smaller.

You are right though, we couldn't hope to get microsecond repeatable dets. from anything we could make at home.

[Jacks Complete]

Jetex Kid, that was the point of my design.

The initiation point is outside the body of the charge, and the shockwave travels downwards, through a narrow constriction, then grows again.

Optically or physically it would be a pinhole, and as the explosion would then appear to radiate from that point, microsecond timings would be consistently achieved. This would be very like your bridge idea, but could be made much smaller.

You are right though, we couldn't hope to get microsecond repeatable dets. from anything we could make at home.

[me234]

I know that this is pretty much unrealistic for us E&W folk, but I just thought it was a pleasant idea to have.
Jack and Jetex, that bridge idea and stuff is damned good, I was worrying about the timing thing.
Jetex, I figure as long as both discs are completely (or at least mostly) detonated and have formed their respective waves fully before the wave front from one disc reaches and bypasses the second disc, then the desired constructive interference can still occur and the effect will be observed.
I don't think a microgram or 2 of primary should make too much of a difference to the secondary when the bridge is initiated.
I think I shall refine the idea, maybe make a pic that'll be self-explanatory.
Thanks for the input, the design should be better now.

[me234]

I know that this is pretty much unrealistic for us E&W folk, but I just thought it was a pleasant idea to have.
Jack and Jetex, that bridge idea and stuff is damned good, I was worrying about the timing thing.
Jetex, I figure as long as both discs are completely (or at least mostly) detonated and have formed their respective waves fully before the wave front from one disc reaches and bypasses the second disc, then the desired constructive interference can still occur and the effect will be observed.
I don't think a microgram or 2 of primary should make too much of a difference to the secondary when the bridge is initiated.
I think I shall refine the idea, maybe make a pic that'll be self-explanatory.
Thanks for the input, the design should be better now.

[hereno]

Though by the time you stuff around creating two seperate "disk" detonators undoubtedly you will end up using twice the explosive instead of less.

Commercial detonators do have a concave end to focus the detonation in a shaped charge like effect, I've seen them. Theres a reference in Fedoroff, and a patent detailing it. Though the usefulness of this is also questioned in the Fedoroff entry. Though since they are still doing it, it may have some merit.

[hereno]

Though by the time you stuff around creating two seperate "disk" detonators undoubtedly you will end up using twice the explosive instead of less.

Commercial detonators do have a concave end to focus the detonation in a shaped charge like effect, I've seen them. Theres a reference in Fedoroff, and a patent detailing it. Though the usefulness of this is also questioned in the Fedoroff entry. Though since they are still doing it, it may have some merit.

[Jacks Complete]

I think that a concave end would also increase slightly the compression of the main charge where the det was pushed in.

Having it work like a shaped charge is what I was aiming for in my diagram.

Given that the comercial dets. have this feature, I suppose the increased heat, etc. makes a difference, and so this idea both has merit and will work!

[Jacks Complete]

I think that a concave end would also increase slightly the compression of the main charge where the det was pushed in.

Having it work like a shaped charge is what I was aiming for in my diagram.

Given that the comercial dets. have this feature, I suppose the increased heat, etc. makes a difference, and so this idea both has merit and will work!