Historical research guide · 1115 · 2008
Conjectured Metastable Super-explosives Formed Under High Pressure for Thermonuclear Ignition
Friedwardt Winterberg
In one minute
Friedwardt Winterberg, writing from the University of Nevada in Reno, asks what happens to ordinary matter when it is squeezed suddenly and very hard — to about 100 megabars, roughly a hundred million atmospheres. His conjecture is that at that pressure the outer electrons of neighbouring atoms melt into one shell while the inner shells form a bridge between the two nuclei. The electrons then drop into a far deeper potential well and hand the energy back as a burst of X-rays carrying kilovolt photons, not the volt-scale photons of ordinary chemistry. Such a material would hold about a thousand times more energy per unit volume than a chemical explosive, and because kilovolt X-rays travel much further before they are absorbed, the burst leaves the surface at an energy flux of order 10¹⁷ watts per square centimetre — enough, he argues, to ignite a thermonuclear microexplosion. He then names three ways to reach that pressure with hardware that already exists, and suggests the effect may already be showing itself in the unexplained kilovolt X-rays from exploding wire arrays.
Connection
Chapter 12 is about lighting a fusion burn without a fission bomb to start it, and this paper offers an ignition source that is neither a laser nor a reactor but a state of matter: energy stored in the electron shells themselves and released as X-rays in a fraction of a nanosecond. Chapter 9 gains a testable signature, because the same mechanism would explain the stubborn kilovolt component in the X-ray bursts of pulsed-power wire arrays.
From the source
Matter put suddenly under a pressure of the order of 100 megabars, which is 10¹⁴ dyn per square centimetre, can transform into molecular excited states bound by inner electron shells with kilovolt potential wells. The electrons then fall into the ground state of the newly formed molecule and release their energy as a burst of kilovolt X-rays, at an energy density of order 10¹⁴ erg per cubic centimetre — about a thousand times more than a combustible chemical at normal pressure. The state is expected to be very unstable, which is why it would be made only in the instant it is needed.Abstract; Section 1, Introduction
The size of the effect follows from a two-centre calculation that already exists. Winterberg’s own order-of-magnitude estimate, treating two nuclei pushed together as a single nucleus of charge 2Ze, gives an energy difference of about 58.5 times Z to the power 2.42 electronvolts, which is roughly 15 kiloelectronvolts for neon. The published two-centre Dirac eigenvalues of Müller, Rafelski and Greiner give, for a twofold reduction in separation, shifts of order 0.35 kiloelectronvolts for bromine with bromine and 1.4 kiloelectronvolts for the heavier pairs, and Winterberg fits them with a simple logarithmic rule in the summed nuclear charge.Section 2, An instructive example; Section 5, and Appendix A
A pressure of 100 megabars is reachable with existing technology in three ways: bombarding a solid target with an intense relativistic electron or ion beam, where Kidder computed 50 megabars for a 1 megajoule, 10 megaelectronvolt, million-ampere beam focused onto a tenth of a square centimetre, so a 2 megajoule beam would give 100; hypervelocity impact of a projectile of density about 20 grams per cubic centimetre at 30 kilometres per second; or a convergent shock wave, whose pressure rises as the radius to the power minus 0.9 by Guderley’s solution, so a tenfold reduction in radius multiplies the pressure by ten.Section 3, Several ways to reach a pressure of 100 Mb
The ignition architecture is a spherical shell in which a convergent shock reaches 100 megabars near the inner radius; the outgoing rarefaction wave launched from that radius carries an intense X-ray burst, and a thermonuclear target placed in the cavity is imploded and ignited by it. Because X-rays are trapped inside high-charge material and degrade into black-body radiation, the super-explosive is to be laid out as small particles, thin wires or sheets embedded in solid hydrogen, thin enough to be transparent to their own X-rays, so that the burst heats the hydrogen instead.Section 5, and Section 9, Thermonuclear Ignition
The mechanism may already be on the bench without being recognised: the unresolved puzzle in electric pulse-power-driven imploding wire arrays is a large kilovolt component in the X-ray burst, which a simple conversion of kinetic into thermal energy cannot explain, since that model predicts a sub-kilovolt black-body spectrum. A wire of radius 2 by 10⁻³ centimetres carrying a million amperes has a surface magnetic field of 10⁸ gauss and a magnetic pressure of 4 by 10¹⁴ dyn per square centimetre — above the threshold the conjecture requires. Unexplained X-ray bursts from cluster impacts faster than 100 kilometres per second are cited as a second instance.Section 8, Possible connection to the release of intense X-ray bursts in electric pulse power driven exploding wire arrays
If it is real, the payoff is a cheaper road to inertial confinement fusion. Intense relativistic electron beams cost orders of magnitude less than lasers and can be transported through a tenuous background gas without replaceable transmission lines; and converting impact energy straight into X-rays rather than heat means a macro-particle needs about 50 kilometres per second to deliver 100 terawatts, instead of the roughly 200 kilometres per second that impact fusion otherwise demands.Conclusion
The way in
https://doi.org/10.1007/s10894-008-9143-4How to cite it
Friedwardt Winterberg (2008) Conjectured Metastable Super-explosives Formed Under High Pressure for Thermonuclear Ignition doi:10.1007/s10894-008-9143-4