Got a question about Eric Lerner's DPF? I'll ask him!

joedead · Post by **joedead** » Tue Nov 03, 2009 11:24 pm

Hey all,

Eric Lerner and the Dense Plasma Focus people are getting together in New York next week. (There's a dinner at Ruby Foo's, open invite.) If anyone has a specific question they'd like me to ask, I'd be more than happy to follow through. Just post it below, and I'll report back with Eric's answer!

http://focusfusion.org/index.php

D Tibbets · Post by **D Tibbets** » Wed Nov 04, 2009 12:35 am

What type of neutron counts have been obtained by focus fusion and others?

How can they control the anode erosion problem?

Is there any expermental evidence for the pinch producing the helical twisting core, of is it it purely theoretical at this point? It's the twisting I'm wandering about, not the apple core shape of the pinch that has been photographed,

Has there been any measurments that supports the claimed bremstrahlung suppresion due to the powerful magnetic fields?

Dan Tibbets

joedead · Post by **joedead** » Wed Nov 04, 2009 2:53 am

I will write them down and ask them, then get his words, verbatim.

hanelyp · Post by **hanelyp** » Wed Nov 04, 2009 6:06 am

I'll second the electrode erosion question, and add a question about how losses are expected to scale relative to fusion power.

rcain · Post by **rcain** » Wed Nov 04, 2009 12:51 pm

Wish him every success

..& keep the info comming on his very informative web site.
An exciting time.

Breakable · Post by **Breakable** » Wed Nov 04, 2009 2:19 pm

Please ask why fusion power is always one month away

chrismb · Post by **chrismb** » Wed Nov 04, 2009 5:29 pm

Why does he think his approach will work better than all the previous DPF experiments that concluded it wasn't a route to viable fusion power? Is it just that little 'twist'? Is that really going to make such a big difference it'll jump the gap of viability?

Also, say more [practically] about this X-ray power conversion idea.

jmc · Post by **jmc** » Thu Nov 05, 2009 1:36 pm

What method has he used to meassure these MegaTesla field that exist spatially over micrometres for nanosecond durations? Or are they simply inferred by the neutron count?

kurt9 · Post by **kurt9** » Thu Nov 05, 2009 4:40 pm

D Tibbets wrote:What type of neutron counts have been obtained by focus fusion and others?

How can they control the anode erosion problem?

Is there any experimental evidence for the pinch producing the helical twisting core, of is it it purely theoretical at this point? It's the twisting I'm wandering about, not the apple core shape of the pinch that has been photographed,

Has there been any measurements that supports the claimed bremstrahlung suppression due to the powerful magnetic fields?

Dan Tibbets

I second these questions.

joedead · Post by **joedead** » Fri Nov 13, 2009 2:49 am

The dinner is over and I had a nice opportunity to sit and chat with Eric and one of his employees, Abdelmoula Haboub. Very cordial dinner. I sat next to Abdel and he took time to answer all my questions.

I didn't have time and the balls to monopolize Eric with all the questions, but I did ask a few. I would've loved to interview him and record his answers, but the informal atmosphere and the drinks kept me from doing so. Anyways, here's the general idea:

1) Electrode Erosion

Eric didn't seem to think this would be a problem as long as they were kept cold, like minus 700 or 800. He didn't say how he planned to do this.

2) Neutron Count

They have already been getting a good count, but because they haven't calibrated their machines yet they've been getting two different results. He says a reliable count will be available soon.

3) Abdel didn't mention any measurements to support bremstrahlung suppression but seemed confident it was under control.

4) When asked, Abdel answered he honestly doesn't know what Eric has in mind for direct X-ray conversion.

Yes, I know this isn't much in terms of answers. I'm hoping to have a chance to talk to him more about DPF in the future. Eric might give a presentation at CUNY next spring. If he does, you can bet I'll be there with a voice recorded and more of your questions.

MSimon · Post by **MSimon** » Fri Nov 13, 2009 3:19 am

1) Electrode Erosion

Eric didn't seem to think this would be a problem as long as they were kept cold, like minus 700 or 800.

0K = -273.15C

0R = -459.67F

0R = 0K

Erosion on a micro level is a competition between bonding forces and activation energy. I have my doubts that cooling is going to give enough advantage in comparison to the activation energies available.

Time will tell. If erosion is not a serious impediment to machine operation it don't matter any way. You just deal with it.

BenTC · Post by **BenTC** » Fri Feb 05, 2010 3:50 pm

Just watched the Google Tech Talk on Focus Fusion...

1) Electrode Erosion - Eric didn't seem to think this would be a problem as long as they were kept cold, like minus 700 or 800. He didn't say how he planned to do this.

That was "under" 700 degress C for Beryllium. Lerner mentioned not wanting to replace the anode more than once a month.

3) Abdel didn't mention any measurements to support bremstrahlung suppression but seemed confident it was under control.

Does this include(or is the same as?) Synchrotron Radiation? Apparently when Plasma Frequency (rate at which electrons vibrate) is greater than half the Synchronton Frequency (electrons circling magnetic field lines), then the Synchrotron Radiation is contained - with higher density producing lower Syncrontron Frequency. Also something to do with quantum effects at high density preventing ions from transfering energy to slow electrons.

4) When asked, Abdel answered he honestly doesn't know what Eric has in mind for direct X-ray conversion.

Many thin layers of foil getting electrons knocked out by xrays. 40% of the power is gathered from the xrays.

chrismb · Post by **chrismb** » Fri Feb 05, 2010 4:07 pm

BenTC wrote:
4) When asked, Abdel answered he honestly doesn't know what Eric has in mind for direct X-ray conversion.
Many thin layers of foil getting electrons knocked out by xrays. 40% of the power is gathered from the xrays.

Bloomin' nonsense. If that were true you'd not be able to analyse sensitive electronics with X-ray imaging, but X-ray-ing is the primary means to do so.

The dream-land fantasies of fusion-wannabies. What a colourful place it is!

kunkmiester · Post by **kunkmiester** » Fri Feb 05, 2010 4:08 pm

Quote:
4) When asked, Abdel answered he honestly doesn't know what Eric has in mind for direct X-ray conversion.

Many thin layers of foil getting electrons knocked out by xrays. 40% of the power is gathered from the xrays.

It makes sense. That's basically how solar panels work, and it works better with more energetic photons. I'm not sure what you'd use that would last a really long time, but the mechanism would be theoretically sound.

chrismb · Post by **chrismb** » Fri Feb 05, 2010 5:02 pm

kunkmiester wrote:
Quote:
4) When asked, Abdel answered he honestly doesn't know what Eric has in mind for direct X-ray conversion.

Many thin layers of foil getting electrons knocked out by xrays. 40% of the power is gathered from the xrays.
It makes sense. That's basically how solar panels work, and it works better with more energetic photons. I'm not sure what you'd use that would last a really long time, but the mechanism would be theoretically sound.

Still bloomin' nonsense, IMHO. Just talking about a thing doesn't make it work.

Solar panels work because the ~unit eV photons interact with the ~unit eV physics in atoms. Fire many kV at it and it'll excite the resonant structures in the atom (the nucleus) and it'll re-emit EM.

The wavelength of excitation of an electron from a visible-light photon will knock it out of a shell, the wavelength of an X-ray will make it wobble in its shell. The scant-few electrons that do get knocked out clearly aren't enough even to generate noticable electrostatic charging, let alone an actual useful current.

If it were that easy, don't you think NASA would've come up with a battery consisting of a gamma-emitting isotope surrounded by foil layers? Instead they use an incredibly poor efficiency plutonium 'thermonuclear' battery.