[FRIAM] technical notes on fusion announcement

[Steve Smith]

I think DT refers simply to the remaining fraction of Deuterium/Tritium 
remaining after the reaction event (-4%) without specific accounting for 
remaining D vs T.

My understanding is that D-T  fusion occurs at a lower temperature than 
D-D but that once fusion commences (starting with D-T), both D-T and D-D 
reactions occurring in similar amounts. In laser-driven ICF (as with 
NIF) I believe the ratio of D/T is nominally 50/50 though it would seem 
to make sense to have a higher T to D ratio but most references I see 
imply equal portions.   An equal number of D-D and D-T reactions would 
seem to consume D more quickly, though as that commences, the D/T ratio 
would go down, making D-T reactions (yet) more likely...   tricky 
business, no wonder it has taken decades to get to this point?

The Wikipedia Entry on ICF is pretty good: 
https://en.wikipedia.org/wiki/Inertial_confinement_fusion

I found several popular science Articles which seem to reinforce my 
sense that this "breakthrough" is not as significant as implied:

    https://www.science.org/content/article/fusion-breakthrough-nif-uh-not-really

Other interesting/relevant links regarding D-T and D-D fusion...

https://www.researchgate.net/publication/263507001_Species_separation_and_modification_of_neutron_diagnostics_in_inertial-confinement_fusion/figures?lo=1

https://www.energy.gov/science/doe-explainsnuclear-fusion-reactions 
<https://www.energy.gov/science/doe-explainsnuclear-fusion-reactions>

https://science.jrank.org/pages/4732/Nuclear-Fusion-D-D-D-T-reactions.html 
<https://science.jrank.org/pages/4732/Nuclear-Fusion-D-D-D-T-reactions.html>

On 12/13/22 4:36 PM, glen wrote:
> That's why I asked. I guess I'll assume DT means both deuterium and 
> tritium, not just deuterium. If you were going to track fuel use, 
> you'd track the rarer part more closely, right?
>
> On 12/13/22 09:22, Frank Wimberly wrote:
>> DT = deuterium?
>>
>> ---
>> Frank C. Wimberly
>> 140 Calle Ojo Feliz,
>> Santa Fe, NM 87505
>>
>> 505 670-9918
>> Santa Fe, NM
>>
>> On Tue, Dec 13, 2022, 10:21 AM glen <gepropella at gmail.com 
>> <mailto:gepropella at gmail.com>> wrote:
>>
>>     Awesome. Thanks. I'm still trying to catch up with the QC 
>> Wormhole kerfuffle. Who knew Quanta was so click baity?
>>
>>     What is "DT"?
>>
>>     On 12/13/22 09:02, Marcus Daniels wrote:
>>      > In case no one wanted to get up at 7:00am to watch DOE 
>> administrators talk:
>>      >
>>      >
>>      > 1. Controlling the laser in space and time was important for 
>> maintaining symmetry.  Timing precision of 25e-12 secs and laser 
>> spatial precision of 5e-12 meter were needed. This was thought to be 
>> the main explanation for the achievement.
>>      >
>>      > 2. 8% more power on the laser this time
>>      >
>>      > 3. x-ray tomography is used to find flaws in the capsules.  
>> Developing software to do the counting.
>>      >
>>      > 4. They have ongoing efforts to study the fabrication systems 
>> and their components (done in Germany) to find idiosyncrasies of each.
>>      >
>>      > 5. Laser technology improvements since NIF was built which are 
>> 20% more efficient.
>>      >
>>      > 6. Target cost is from labor, and it takes 7 months each
>>      >
>>      > 7. 4% of DT is burned in a shot
>>      >
>>      > 8. Machine learning ties together radiation hydrodynamics and 
>> experimental data.   (It sounded preliminary.)
>>      >
>>      > 9. The (successful) capsule had more defects than previous 
>> experiments.   However, previous experiments did show benefits from 
>> capsule quality.
>>      >
>>      > 10. 15% of experiments are indirect drive of this kind, 15% of 
>> experiments are other approaches to ignition.  The rest are weapons 
>> and materials characterization.
>>      >
>>      > 11. Anomalous laser directional control were problems in the 
>> summer runs.   Fixed that.
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://redfish.com/pipermail/friam_redfish.com/attachments/20221213/e78b5600/attachment.html>