I take it 400-keV electrons is a good thing, but is there a significant difference between 400-keV electrons and, say, 100-keV ions, as reported a year ago?

Anyway, best wishes for the coming year and the move beyond deuterium.

wolfram wrote: In most plasmas that I’m familiar with, electrons are consistently much hotter than ions.

That depends on the heating mechanism. For example, resistive heating is only significant for electrons, so they can get to a higher temperature this way. But this heating mechanism is only capable of getting plasmas to a few keV not >100keV (since resistivity falls with temperature).

Alternatively, as in tokamaks, ion cyclotron resonant heating (ICRH) can be used to specifically heat just the ions.

In the case of DPF, I see the 400keV electron temperature as a bad thing since it leads to excessive bremsstrahlung radiation losses. The key will be if the proportion of energy going to raise the electron temperature can be limited enough with the switch to p-B11 fuel.

jamesr wrote:
In the case of DPF, I see the 400keV electron temperature as a bad thing since it leads to excessive bremsstrahlung radiation losses. The key will be if the proportion of energy going to raise the electron temperature can be limited enough with the switch to p-B11 fuel.

actually, seeing these 400 keV electrons represents a good opportunity to test and quantify the magnetic field effect. gigagauss fields should suppress them. so just how powerful is the effect?

Its not about quantity. Quality is what matters. LPP, being a private commercial enterprise, are not going to just upload all their raw data. It has to be analysed and interpreted. There will be many series of shots testing and calibrating diagnostics, coming up with new combinations of timing, voltage, pressure and other adjustments before each set of actual ‘optimised’ experimental shots to gather proper data.

If you watch some of the videos posted previously it only takes a few minutes to setup and fire a shot, so I’d think they could do a couple an hour. If it has been opened up for cleaning or other adjustments though it would take a day or two to get back to operating conditions.

jamesr wrote: Its not about quantity. Quality is what matters.

I acknowledge their rights regarding what data they do or do not release, but I also want to make clear, they’re shooting for an industrial result. Quantity is exactly the quality they are looking for. If they can genuinely get an excess of 1, 5 or 10 megajoules a shot, but each shot takes a week of set up, the method and device won’t be very practical. It will provide a giant flag for where to investigate next though. Which will be nice, since I’ll be in need of a thesis subject by about that time.

Megajoules, yikes! 10kJ of fusion energy will be just fine for us on just the other side of the concrete wall, thanks ;-D

Wow, great result on the high energy x-rays. I agree that quality is important but quantity is a big deal as well. The result of 5 shots of repeatability was nice but it’s a far cry from what I would call statistically significant. A hundred or thousand shots would be far better. I know this requires a great deal of engineering on the pulse power and other components but that is the long term goal right; operating at ~10 Hz all the time. It sounds like the physics is being sorted out nicely so when is the engineering of the pulse power going to begin?

One questions: where are the x-rays coming from? Are they generated in the pinch itself via brems or are they coming from the anode brems? I thought LPP had a diagnostic for hard x-ray imaging develop by Dr. Murali. I’d love to see the pics if they exist. I find the HXR images more telling than visible images.

Also, we know the x-rays are coming from the plasmoid because the line of sight to the anode is blocked for the time-of-flight detectors by two inches of lead. We don’t have x-ray images yet, but hope to soon when we get bigger x-ray yields. These willbe images of the x-rays emitted at much lower energies–30 keV–because the 400 keV x-rays will go through our imaging foil with no trouble.