Untitled Document
No prophet in his own country
August 6, 2013
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the videos where he praises this project
http://www.youtube.com/watch?v=_MoPydT_Zrg
http://www.youtube.com/watch?v=Fi_uurHZY-g&list=TLCp-mzvm_s6E **** **
| And here is a significant passage, with its translation | ; | Bad news for LIFE and high-energy-density physics | The delay in reaching ignition “is not a crisis for stockpile stewardship, but it is a total crisis for people who think of energy applications,” says Crandall, who spent his last two years at the Department of Energy studying prospects for laser-fusion energy. | “It doesn’t make sense to plan an energy program until we get to ignition. | ” He calls Livermore’s advocacy of the Laser Inertial Fusion Energy (LIFE) plan “a huge mistake” because it claimed that a diode-pumped megajoule-class laser could be firing several pulses per second to drive a prototype fusion reactor within a decade. | “Over-promising did not play well with Congress.” | Translation : | Bad news for the LIFE program and high-energy-density physics. | The delay in reaching ignition ( | the start of a fusion reaction due to the focusing of the energy of 192 lasers) | is not only a crisis for the management of the American nuclear arsenal ( | as that was the primary goal of this project | ). it is also a total crisis among people who thought they could consider energy applications, says Crandall, who spent the last two years studying the prospects for laser-fusion energy. | "It makes no sense to plan anything until we achieve ignition." | He recalls that the people at Livermore advocating the Laser Inertial Fusion Energy (LIFE) program was a huge mistake. Indeed, they claimed that a diode-pumped megajoule-class laser could fire several pulses per second to drive a prototype fusion reactor within a decade (...). | "Congress did not appreciate these false promises." |
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I remind you that the academician Guy Laval led, on behalf of the Paris Academy of Sciences, a commission that studied the different possibilities for obtaining energy through fusion. A report was published in 2007.
I called Laval six months ago and told him, "It would be appropriate for the Academy of Sciences to publish a supplement to this report, revising downward the alleged estimates regarding laser fusion."
But he will do nothing. This project has become "political." Indeed, the conclusion that would be forced would be to put the French Megajoule project on hold and stop the expenses.
He will do nothing. No one will do anything. Our scientific media are also under orders. Personally, all I will be able to do is use my talents as a popularizer to explain why it didn't work and especially why it won't work.
There is a missing factor of 50 in the energy to be focused on the target
It is impossible to extract more energy from these neodymium-doped glass lasers: they would explode.
Who would think of multiplying the number of lasers by ... 50 ! ?!
Laval told me
- The military say they never aimed for ignition (...). *Thanks to this Megajoule bench, they will be able to test the behavior of materials under time-modulated X-ray fluxes. *
Completely false. It is true that with these benches, one can precisely modulate the laser energy output in the form of ultraviolet, but we absolutely do not control what happens in the hohlraum, in this small cylindrical gold box, where, to use the journalists' expression, "we will create a tiny hell."
The hohlraum, in gold
**The distribution of spots, which are the impacts of the laser beams on the gold wall
**which re-emits them in the form of X-rays on the target, represented by this white ball
Initially, the theorists from Livermore, John Lindl in the lead, had decided to place 64 laser spots on each ring. These rings of spots were supposed to create a well-homogeneous X-ray emission in the hohlraum (a word meaning "oven" in German). In order to evenly irradiate the ablator (the outer layer covering the small spherical pellet). The expansion of this ablator is then supposed to achieve a spherical symmetry compression.
What happened during the first tests? The people from Livermore ended up with a target that turned into a ... pizza. The central ring emitted ... less than the two located closer to the openings. Why? Because the beams had a longer path to travel in what became a gold plasma immediately. Interacting with this plasma, the beams pointing to the central ring lost energy.
This had absolutely not been predicted!
The people from Livermore then decided to modify their setup by sending 25% of the energy to each of the two outer rings, and the remaining 50% to the central ring (why not 20% - 60% - 20%?). As noted by the DOE (Department of Energy) report (in their July 2012 report), this research, which was supposed to be guided by computer simulations with the highest precision, turned into the most complete empiricism.
The results (very precise and reliable) of the measurements carried out in the hohlraum (through windows made for this purpose) had so little to do with the values predicted by the theorists that these people even asked in their report "if these scientific calculations could really be of any use in guiding this kind of experiment" (...). This report specified that these same theorists should re-examine all the models they had developed regarding the laser-wall interaction.
Thus, even if the UV power emitted by the "driver" (the laser bench) can be carefully modulated in time, what is emitted in the oven is currently beyond any control, and Laval says ... nonsense.
What are the members of our Academy of Sciences for? Are they there to advance research and knowledge or to serve the military by offering them luxury toys, or to the industrialists so they can benefit from lucrative contracts?
Before the launch of the NIF test campaign (2010-2012), John Lindl had stated, during the conference he gave in 2007, on the occasion of receiving the Maxwell Prize (hold on!), that it was out of the question to doubt the success of the operation and that these experiments would aim to slightly adjust the parameters allowing the simulations to be controlled. He ...