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http://www.space.com/businesstechnology ... ction.html
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Lots of fusion related bits.
Which got me to thinking. If ions are pulsing in the reactor space - in to the center and out near the grid. And electrons are rotating around the edge of the wiffle ball at what velocity ratio would they synchronize?
Right now I'm having a hard time visualizing the electron paths viz the wiffle ball.
Then I got to wondering. Suppose we could get a rotating electric field to spin up the electrons.
For the larger reactors (100 MW and up). The POPS frequency is in the 100 to 200 KHz range. Even at 10 MHz (test reactor size) I could envision driving at least 4 of the grids with 90 deg phase difference between them. That would control the electron spin around the wiffle ball. I just did some quick calcs and found the electron spin around the wiffle ball should be from about 17 to 56X times the POPS frequency assuming a 2 pi r distance for electrons to travel and r for ions - depending on the ion, from protons to B11.
The other two grids could be used for POPS frequencies.
Space Magnetism
Space Magnetism
Engineering is the art of making what you want from what you can get at a profit.
Re. the electron path in a wiffle ball:
Given the diamagnetic effect of the electron cloud, magnetic field beyond a short distance inside the electron cloud approaches zero. I'm thinking a reasonable approximation of electron path might be electrons bouncing off the electron cloud / magnetic field interface between arcs through the interior influenced mostly by the electric field.
Re. giving the electron cloud a net spin:
I'm thinking not a good idea. Spinning the charged cloud would give it a directional magnetic field pushing it off center if not out of the magrid.
Given the diamagnetic effect of the electron cloud, magnetic field beyond a short distance inside the electron cloud approaches zero. I'm thinking a reasonable approximation of electron path might be electrons bouncing off the electron cloud / magnetic field interface between arcs through the interior influenced mostly by the electric field.
Re. giving the electron cloud a net spin:
I'm thinking not a good idea. Spinning the charged cloud would give it a directional magnetic field pushing it off center if not out of the magrid.
Yeah. Except that it has to be flowing already to get the diamagnetic effect. Stationary charges generate no magnetic fields.hanelyp wrote:Re. the electron path in a wiffle ball:
Given the diamagnetic effect of the electron cloud, magnetic field beyond a short distance inside the electron cloud approaches zero. I'm thinking a reasonable approximation of electron path might be electrons bouncing off the electron cloud / magnetic field interface between arcs through the interior influenced mostly by the electric field.
Re. giving the electron cloud a net spin:
I'm thinking not a good idea. Spinning the charged cloud would give it a directional magnetic field pushing it off center if not out of the magrid.
So I'm trying to imagine the flow. Then I'm trying to imagine how to control it.
Engineering is the art of making what you want from what you can get at a profit.
Free electrons are not the same as bound ones. Diamagnetism refers to the magnetic response of a material.
Free electron currents in the Polywell can be viewed in many ways. One way is to think about the full current as a fluid rather than individual particles. The currents along field lines will be much higher than the currents perpendicular to them. But if the currents along field lines are high enough, they create a magnetic field perpendicular to that path. The net end result is an unstable mess - the local field the electrons follow is different than the imposed external field.
If the MaGrid has 200k amp-turns, you'll need 1000's of amps in the local electron fluid to create a matching B field. I would hope we don't need to get that high so confinement will be simple.
Free electron currents in the Polywell can be viewed in many ways. One way is to think about the full current as a fluid rather than individual particles. The currents along field lines will be much higher than the currents perpendicular to them. But if the currents along field lines are high enough, they create a magnetic field perpendicular to that path. The net end result is an unstable mess - the local field the electrons follow is different than the imposed external field.
If the MaGrid has 200k amp-turns, you'll need 1000's of amps in the local electron fluid to create a matching B field. I would hope we don't need to get that high so confinement will be simple.
So where does the Wiffle Ball Effect come from?drmike wrote:Free electrons are not the same as bound ones. Diamagnetism refers to the magnetic response of a material.
Free electron currents in the Polywell can be viewed in many ways. One way is to think about the full current as a fluid rather than individual particles. The currents along field lines will be much higher than the currents perpendicular to them. But if the currents along field lines are high enough, they create a magnetic field perpendicular to that path. The net end result is an unstable mess - the local field the electrons follow is different than the imposed external field.
If the MaGrid has 200k amp-turns, you'll need 1000's of amps in the local electron fluid to create a matching B field. I would hope we don't need to get that high so confinement will be simple.
Engineering is the art of making what you want from what you can get at a profit.
My reading is that he pushes the current up to get a measure of the electron density and then assumes a relationship for places he can't measure.
I admit other sections he's written up, I'm really confused by the description. I bet the model Bussard has is a good one, and I'm just not used to it.
For example, I don't understand "recirculation". Seems to me the plasma is trapped inside the ball and that's where you want it.
It might be Bussard is thinking of the electron fluid as trapped so a model of diamagnetism makes sense - I just don't get it.
Semantics doesn't matter so long as we make it work!
I admit other sections he's written up, I'm really confused by the description. I bet the model Bussard has is a good one, and I'm just not used to it.
For example, I don't understand "recirculation". Seems to me the plasma is trapped inside the ball and that's where you want it.
It might be Bussard is thinking of the electron fluid as trapped so a model of diamagnetism makes sense - I just don't get it.
Semantics doesn't matter so long as we make it work!
I don't get it either. In fact one of the critics of the device asked me that very question. What is the flow of charged particles that produces the wiffle ball effect?
That was asked me almost a year ago. It still bothers me.
But I see we are on the same page. Maybe we call it a diamagnetic effect for now.
Think about it. You have electrons in synchronized bunches going in and out of the reaction volume. Which is going to modulate the magnetic field. How and how much? The current will be at a peak just as the bunches pass through the center of the coils.
What you would need for a WB is loops of circulating current near each coil. I don't see it as stable. In fact I don't see it at all. Which may just be a defect on my part.
That was asked me almost a year ago. It still bothers me.
But I see we are on the same page. Maybe we call it a diamagnetic effect for now.
Think about it. You have electrons in synchronized bunches going in and out of the reaction volume. Which is going to modulate the magnetic field. How and how much? The current will be at a peak just as the bunches pass through the center of the coils.
What you would need for a WB is loops of circulating current near each coil. I don't see it as stable. In fact I don't see it at all. Which may just be a defect on my part.
Engineering is the art of making what you want from what you can get at a profit.
That's why I want to see the math. The trick is the assumptions. Bussard made assumptions based on experience and measurement. I want to see models that verify it, or at least show that it is a reasonable way to look at things.
Full plasmas do weird things. If I can watch the weirdness unfold both numerically and experimentally with even 30% matching I'll say I "understand it". The wiffle-ball is a 3D cusp-mirror combo that is very cool physics. I may not be able to describe it in words, but it should be possible to get close with math!
Full plasmas do weird things. If I can watch the weirdness unfold both numerically and experimentally with even 30% matching I'll say I "understand it". The wiffle-ball is a 3D cusp-mirror combo that is very cool physics. I may not be able to describe it in words, but it should be possible to get close with math!
Plasmas are every where in space - from the stars to the stuff between stars to the center of galaxies. Densities vary from nothing in between galaxies (1 particle per cubic meter) to the edge of a black hole (and nobody with sense will guess what's on the other side of a black hole yet!) at almost neutron star density.
The rules are all the same. But you can ignore some effects in a dense plasma that are important in a weak one and vice versa. To me, the pictures help understand the weirdness. I just wish I could find ways to draw them better!
The numbers on a solar flare are mind boggling - from the total mass ejected to the total energy being flung out (it goes way past orbital velocity - from the surface of the sun!)
Nice picture, thanks!!
The rules are all the same. But you can ignore some effects in a dense plasma that are important in a weak one and vice versa. To me, the pictures help understand the weirdness. I just wish I could find ways to draw them better!
The numbers on a solar flare are mind boggling - from the total mass ejected to the total energy being flung out (it goes way past orbital velocity - from the surface of the sun!)
Nice picture, thanks!!
Regarding the amount of circulating current, let me tell you about an event with PXL-1. This was a closed-box machine (magnets outside) of the same general form as HEPS and WB-5, but built to run for 30-sec or so at a time. It had some fascinating behavior, and I was never quite completely sure why it did some of the things it did.
I don't have the notes on this unit, but it was run in two different configurations. I don't recall for sure which configuration this test was run in, but probably the second. The first mode was a hot (positive) accelerator grid and a grounded cathode. The second mode was to have a grounded accelerator grid (same potential as the walls) and a hot (highly negative voltage) cathode. There was only a single electron gun.
The first mode produced a shallow potential well, evidenced by a negative voltage of some tens of volts on a Langmuir probe in the center. The electrons passed the accelerating grid of the gun at high KE, but upon passing it would lose KE to it. They were not attracted to the walls, so cusp losses would be low.
The second mode should have the electrons at high KE, not losing to the accel grid because they were equally attracted to the walls, but cusp losses should have been high.
The routine was to run a computer-driven sequence of testing, but manually-driven ramping of the high voltage (autotransformer, step-up transformer, full wave rectifier, and about 8 mfd of filter (almost nothing at 60 Hz). Magnet shutoff was 1 second after high voltage shutoff (line power to the autotransformer was on a computer-controlled relay).
Typically, the e-gun current was very high, about 2 amps, initially, but would drop to about 50 mA after a couple of seconds at high voltage. I was interpreting this as either poisoning or deactivation of the dispenser cathode (ion bombardment could have been blowing the low-work-function stuff off the surface). I belive I was wrong.
Attempting to get the voltage up, I had such a run in which the beam current shut down on its own to the 50 mA level. The computer shut off the high voltage on schedule. The voltage on the cathode was falling when the magnets shut off 1 sec later, but was still at 4 kV.
The magnet current was controlled by a Seimens magnetic blowout contactor, driven by a fiber optic line (a voltage isolation measure for MaGrid models). Current was monitored by a 500A clamp-on DC ammeter and a computer data acquisition system. The contactor had a damper diode to kill flux linkage in the magnets. When the contactor opened, it sounded like somebody had set an M-80 off in that corner of the lab, instead of the usual soft pop. The computer recorded a reversal of current from the magnet batteries from less than 100 to -350 amps, lasting 1/2 second! The current actually reversed direction and charged the battery bank momentarily! I forget the battery voltage ... 100-200 volts probably. This was a huge pulse of power. The filter cap on the HV supply could not have caused it, and in any case this was from magnets outside the stainless steel vacuum vessel, in no physical contact with the plasma. The event had bulled its way past the contactor ... effective arc length of a meter or so (see the Seimens literature on this kind of contactor), and also blew a 1000A damper diode I had across the magnets, which had a large margin of back-voltage capability. Normally, on opening the contactor, the damper diode would have forward-conducted, so the pulse was backwards from a normal magnet shut-down.
My conclusion was that the device had not "gone dead", it was simply chock full of every electron it could hold, at high KE. Dropping the magnetic field dropped containment, and their resultant rush to the walls caused an EMP that induced back EMF in the magnets. The energy stored was stupendous. Upon realizing this, I declared that PXL-1 was a "flux capacitor."
I also concluded that the machine was, in fact, making a fairly effective wiffleball, or something comparable. Corner cusp losses suddenly shut down to a low level. I always wondered if low-energy electrons (which would mag-mirror off the cusps) were being tamped in to the corners by repulsion from the high-energy population.
Anyway, the point is, don't jump to conclusion that the effective current of electrons circulating in these things is somehow "small".
I don't have the notes on this unit, but it was run in two different configurations. I don't recall for sure which configuration this test was run in, but probably the second. The first mode was a hot (positive) accelerator grid and a grounded cathode. The second mode was to have a grounded accelerator grid (same potential as the walls) and a hot (highly negative voltage) cathode. There was only a single electron gun.
The first mode produced a shallow potential well, evidenced by a negative voltage of some tens of volts on a Langmuir probe in the center. The electrons passed the accelerating grid of the gun at high KE, but upon passing it would lose KE to it. They were not attracted to the walls, so cusp losses would be low.
The second mode should have the electrons at high KE, not losing to the accel grid because they were equally attracted to the walls, but cusp losses should have been high.
The routine was to run a computer-driven sequence of testing, but manually-driven ramping of the high voltage (autotransformer, step-up transformer, full wave rectifier, and about 8 mfd of filter (almost nothing at 60 Hz). Magnet shutoff was 1 second after high voltage shutoff (line power to the autotransformer was on a computer-controlled relay).
Typically, the e-gun current was very high, about 2 amps, initially, but would drop to about 50 mA after a couple of seconds at high voltage. I was interpreting this as either poisoning or deactivation of the dispenser cathode (ion bombardment could have been blowing the low-work-function stuff off the surface). I belive I was wrong.
Attempting to get the voltage up, I had such a run in which the beam current shut down on its own to the 50 mA level. The computer shut off the high voltage on schedule. The voltage on the cathode was falling when the magnets shut off 1 sec later, but was still at 4 kV.
The magnet current was controlled by a Seimens magnetic blowout contactor, driven by a fiber optic line (a voltage isolation measure for MaGrid models). Current was monitored by a 500A clamp-on DC ammeter and a computer data acquisition system. The contactor had a damper diode to kill flux linkage in the magnets. When the contactor opened, it sounded like somebody had set an M-80 off in that corner of the lab, instead of the usual soft pop. The computer recorded a reversal of current from the magnet batteries from less than 100 to -350 amps, lasting 1/2 second! The current actually reversed direction and charged the battery bank momentarily! I forget the battery voltage ... 100-200 volts probably. This was a huge pulse of power. The filter cap on the HV supply could not have caused it, and in any case this was from magnets outside the stainless steel vacuum vessel, in no physical contact with the plasma. The event had bulled its way past the contactor ... effective arc length of a meter or so (see the Seimens literature on this kind of contactor), and also blew a 1000A damper diode I had across the magnets, which had a large margin of back-voltage capability. Normally, on opening the contactor, the damper diode would have forward-conducted, so the pulse was backwards from a normal magnet shut-down.
My conclusion was that the device had not "gone dead", it was simply chock full of every electron it could hold, at high KE. Dropping the magnetic field dropped containment, and their resultant rush to the walls caused an EMP that induced back EMF in the magnets. The energy stored was stupendous. Upon realizing this, I declared that PXL-1 was a "flux capacitor."
I also concluded that the machine was, in fact, making a fairly effective wiffleball, or something comparable. Corner cusp losses suddenly shut down to a low level. I always wondered if low-energy electrons (which would mag-mirror off the cusps) were being tamped in to the corners by repulsion from the high-energy population.
Anyway, the point is, don't jump to conclusion that the effective current of electrons circulating in these things is somehow "small".
Tom the Battery Charging says that the field is not a Lorentz opposing field but some kind of aiding field.
Which is kind of what I guessed would be needed to get the wiffle ball effect.
We really have a lot to learn about how all this works.
Which is kind of what I guessed would be needed to get the wiffle ball effect.
We really have a lot to learn about how all this works.
Engineering is the art of making what you want from what you can get at a profit.
Well luckily you weren't travelling at 88mph, or you would have been in some serious shitTom Ligon wrote: The energy stored was stupendous. Upon realizing this, I declared that PXL-1 was a "flux capacitor."
But seriously Tom thats fascinating stuff. So what you were saying was that large energy was stored in either a oscillating or spinning (or both ?) electron cloud. I wonder if we could accurately trap and measure the surge of energy that gets released. If we know how much energy we put in we could start designing some experiments to so see how much energy is trapped in the ball and how much recirculates/gets lost.
Its plausible the single cathode emitter could have been just right to spin it up. You could infact have discovered a new energy storage device. Virtual cathode flywheels.
I cant say how valuable it is to hear from someone who was actually there. Cheers.
Purity is Power
Now think of taking four of the six grids and applying a rotating electrostatic field to them. i.e. each grid is electrically 90 deg (+ or - depending) from the adjacent grid. Now suppose you did POPS on the remaining two grids.Keegan wrote:Well luckily you weren't travelling at 88mph, or you would have been in some serious shit :)Tom Ligon wrote: The energy stored was stupendous. Upon realizing this, I declared that PXL-1 was a "flux capacitor."
But seriously Tom thats fascinating stuff. So what you were saying was that large energy was stored in either a oscillating or spinning (or both ?) electron cloud. I wonder if we could accurately trap and measure the surge of energy that gets released. If we know how much energy we put in we could start designing some experiments to so see how much energy is trapped in the ball and how much recirculates/gets lost.
Its plausible the single cathode emitter could have been just right to spin it up. You could infact have discovered a new energy storage device. Virtual cathode flywheels.
I cant say how valuable it is to hear from someone who was actually there. Cheers.
Engineering is the art of making what you want from what you can get at a profit.