Tri Alpha Presentations – Wow – but not aneutronic

[Matt M]

Here is a link to a PPT presentation from Tri Alpha Energy.

They are appear to be very far along on their process that is colliding two plasma
toroids into each other at high supersonic speeds.

Check out the shot numbers on their graphs. It appears they are
5800+!

But, they reference deuturium recycling and residue issues. So, they
don’t appear to be working in the aneutronic arena.

Matt

http://www.iccworkshops.org/icc2011/uploads/241/icc2011_gota_talk_8_16_11.pdf

[zapkitty]

Tri-Alpha is still supposed to be aneutronic last I knew.

That pdf appears to be a rather specialized report on the development of just one aspect of their concept. Tri-Alpha is supposed to achieve aneutronic fusion by combining the Field-Reversed Configuration concept with the Colliding Beam concept. Collide two plasmas into one FRC and then collide ion beams in the plasma. The C2 experimental device is for developing the FRC part of that and apparently does not (yet) have the colliding ion beam stuff. The use of deuterium would be a natural part of such testing.

But this mixture of techniques, combined with Tri-Alpha’s secrecy, seems to have led to a great deal of confusion among those who follow fusion tech, as one D-T fusion concept uses the colliding FRC variant to achieve neutronic fusion on its own. That’s what Helion Energy is attempting, as a matter of fact.

So this report does not necessarily conflict with Tri-Alpha going for aneutronic fusion.

Edit: a link to an old NBF article that mentions this…
http://nextbigfuture.com/2007/06/tri-alpha-energy-raises-40-million-in.html

[JimmyT]

Matt M wrote: Here is a link to a PPT presentation from Tri Alpha Energy.

They are appear to be very far along on their process that is colliding two plasma
toroids into each other at high supersonic speeds.

Check out the shot numbers on their graphs. It appears they are
5800+!

But, they reference deuturium recycling and residue issues. So, they
don’t appear to be working in the aneutronic arena.

Matt

http://www.iccworkshops.org/icc2011/uploads/241/icc2011_gota_talk_8_16_11.pdf

I doubt that their shot numbers started with 1. Maybe they started this current run at 5,000?

[jamesr]

Other shots numbers in the pdf are much higher such as #18409, so even if they didn’t start from 1 they must have done a fair few.

[JimmyT]

I’m not sure about this, but I believe Eric’s shot numbers are randomly assigned.

Aaron could you chime in on this?

[AaronB]

Our shots are numbered by date first, and then the shot number for that day. Today’s first shot would be 08311101 (month, day, year, shot #).

[Tulse]

Why month-day-year, instead of year-month-day? Is the hope that everything will be wrapped up by the end of December? 🙂

[vansig]

AaronB wrote: Our shots are numbered by date first, and then the shot number for that day. Today’s first shot would be 08311101 (month, day, year, shot #).

there is no good reason not to switch every date code to year-month-day, which is reasonable since computer operating systems automatically sort file names into lexicographic order.

the practice of ordering things month-day-year should be subjected to public ridicule.

[Brian H]

vansig wrote:

Our shots are numbered by date first, and then the shot number for that day. Today’s first shot would be 08311101 (month, day, year, shot #).

there is no good reason not to switch every date code to year-month-day, which is reasonable since computer operating systems automatically sort file names into lexicographic order.

the practice of ordering things month-day-year should be subjected to public ridicule.

Agree! But it’s hard. Y-M-D was adopted as the ANSI standard decades ago, and is still ignored. I use it wherever I can, however.
I still twitch when I remember my coding days having to pluck strings apart, reformat from text to numeric, resequence, sort, etc.

[malaga2022]

It is impossible being aneutronic working in <1keV range (I couldnt go over 100 eV without matter compression over 100x solids), they need reduce plasma size and increase plasma temperature to 1MeV range.

How tri alpha measures plasma temperature?

[jamesr]

malaga2022 wrote:
How tri alpha measures plasma temperature?

Ion temperature is found via a spectrometer looking at the doppler broadening of line emission. You also get the flow towards/away from the detector via the blue/red-shift of the line. NB since the deuterium will be fully ionized except at the very cool edge, it is normal to look for the transitions of impurity ions like carbon C6+ -> C5+. The measurement will be the average along the line of sight.

Electron temperature is done via Thomson scattering, whereby a high power laser pulse is fired through the plasma, a few photons are scattered off the electrons back to a another spectrometer camera looking for the doppler broadening of the scattered laser light. Here normally the laser & detector are arranged so you get a profile of temperature across the plasma. http://en.wikipedia.org/wiki/Plasma_diagnostics#Thomson_scattering

[malaga2022]

What is the percentage of laser that is scattered by the plasma?

It is very important, because if laser can go through the plasma, also plasma radiation, so plasma would radiate so quick that it would be impossible to heat it up:

Pemit=area*C*T^4

C=emision coefficient
If area=1m2 and temperature is 20keV (20000*11600 ºK),
Pemit=C*2.9e33 watts (Sun power is 1e24)

I think plasma area must be very very little in order to reduce plasma emission

[jamesr]

malaga2022 wrote: What is the percentage of laser that is scattered by the plasma?

Magnetically confined plasmas are at such a low density that the chance of a photon scattering is incredibly small.
Typically for a Thomson scattering laser system you’d get back 1 photon for every 10^14 – so if the laser pulse is 3GW around 30 micro Watts get back to the detector.
or in percentage terms 0.0000000000001%

I’m not sure what you mean by the rest of your comment??

This give a bit more background on the systems used at MAST, JET and what is proposed for ITER
http://www-fusion-magnetique.cea.fr/ppe/TrainingWeekCulham/OpticalDiagnostics-ScatteringDiagnostics-MarkKempenaars.ppt.

The Tri-alpha plasma will be a little bit denser than a tokamak, so they can get away with a slightly less powerful laser, but the fundamentals are the same.

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