Cluster impact fusion

Last updated

Cluster Impact Fusion is a suggested method of producing practical fusion power using small clusters of heavy water molecules directly accelerated into a titanium-deuteride target. Calculations suggested that such a system enhanced the cross section by many orders of magnitude. It is a particular implementation of the larger beam-target fusion concept.

The idea was first reported by researchers at Brookhaven in 1989. [1] [2] Intrigued by recent reports of cold fusion, they attempted to study potential causes for the effect by accelerating tiny droplets of heavy water, about 25 to 1300 D2O molecules each, into a target at about 220 eV. To their surprise they immediately saw fusion effects, at a rate that was many times what any of them could explain via conventional theory. [3]

The experiment was fairly simple in concept but required an appropriate accelerator, so it was some time before other labs were able to repeat the experiments. [4] One of the first was the University of Washington, who reported a null result in 1991. Further experiments and a review from MIT in 1992 solved the mystery: the fusion products were the results of contamination, which could be eliminated by filtering with a magnet. [5] [6] [7] The Brookhaven experimenters tried this and the effect disappeared.

Cluster impact fusion references end abruptly at that point.[ citation needed ]

See also

Related Research Articles

Samuel C. C. Ting Nobel prize winning physicist

Samuel Chao Chung Ting is an American physicist who, with Burton Richter, received the Nobel Prize in 1976 for discovering the subatomic J/ψ particle. More recently he has been the principal investigator in research conducted with the Alpha Magnetic Spectrometer, a device installed on the International Space Station in 2011.

Field-reversed configuration Magnetic confinement fusion reactor

A field-reversed configuration (FRC) is a type of plasma device studied as a means of producing nuclear fusion. It confines a plasma on closed magnetic field lines without a central penetration. In an FRC, the plasma has the form of a self-stable torus, similar to a smoke ring.

Exotic hadron Subatomic particles consisting of quarks and gluons

Exotic hadrons are subatomic particles composed of quarks and gluons, but which — unlike "well-known" hadrons such as protons, neutrons and mesons — consist of more than three valence quarks. By contrast, "ordinary" hadrons contain just two or three quarks. Hadrons with explicit valence gluon content would also be considered exotic. In theory, there is no limit on the number of quarks in a hadron, as long as the hadron's color charge is white, or color-neutral.

Belle experiment

The Belle experiment was a particle physics experiment conducted by the Belle Collaboration, an international collaboration of more than 400 physicists and engineers, at the High Energy Accelerator Research Organisation (KEK) in Tsukuba, Ibaraki Prefecture, Japan. The experiment ran from 1999 to 2010.

Light dark matter Dark matter weakly interacting massive particles candidates with masses less than 1 GeV

Light dark matter, in astronomy and cosmology, are dark matter weakly interacting massive particles (WIMPS) candidates with masses less than 1 GeV. These particles are heavier than warm dark matter and hot dark matter, but are lighter than the traditional forms of cold dark matter, such as Massive Compact Halo Objects (MACHOs). The Lee-Weinberg bound limits the mass of the favored dark matter candidate, WIMPs, that interact via the weak interaction to GeV. This bound arises as follows. The lower the mass of WIMPs is, the lower the annihilation cross section, which is of the order , where m is the WIMP mass and M the mass of the Z-boson. This means that low mass WIMPs, which would be abundantly produced in the early universe, freeze out much earlier and thus at a higher temperature, than higher mass WIMPs. This leads to a higher relic WIMP density. If the mass is lower than GeV the WIMP relic density would overclose the universe.

Subir Sachdev is Herchel Smith Professor of Physics at Harvard University specializing in condensed matter. He was elected to the U.S. National Academy of Sciences in 2014, and received the Lars Onsager Prize from the American Physical Society and the Dirac Medal from the ICTP in 2018. He was a co-editor of the Annual Review of Condensed Matter Physics from 2017-2019.

High-precision experiments could reveal small previously unseen differences between the behavior of matter and antimatter. This prospect is appealing to physicists because it may show that nature is not Lorentz symmetric.

Time crystal Structure that repeats in time; a novel type or phase of non-equilibrium matter

In condensed matter physics, a time crystal is a quantum system of particles whose lowest-energy state is one in which the particles are in repetitive motion. The system cannot lose energy to the environment and come to rest because it is already in its quantum ground state. Because of this, the motion of the particles does not really represent kinetic energy like other motion; it has "motion without energy". Time crystals were first proposed theoretically by Frank Wilczek in 2012 as a time-based analogue to common crystals — whereas the atoms in crystals are arranged periodically in space, the atoms in a time crystal are arranged periodically in both space and time. Several different groups have demonstrated matter with stable periodic evolution in systems that are periodically driven. In terms of practical use, time crystals may one day be used as quantum computer memory.

Tokamak sawtooth Relaxation in the core of tokamak plasmas

A sawtooth is a relaxation that is commonly observed in the core of tokamak plasmas, first reported in 1974. The relaxations occur quasi-periodically and cause a sudden drop in the temperature and density in the center of the plasma. A soft-xray pinhole camera pointed toward the plasma core during sawtooth activity will produce a sawtooth-like signal. Sawteeth effectively limit the amplitude of the central current density. The Kadomtsev model of sawteeth is a classic example of magnetic reconnection. Other repeated relaxation oscillations occurring in tokamaks include the edge localized mode (ELM) which effectively limits the pressure gradient at the plasma edge and the fishbone instability which effectively limits the density and pressure of fast particles.

Bernstein–Greene–Kruskal modes are nonlinear electrostatic waves that propagate in an unmagnetized, collisionless plasma. They are nonlinear solutions to the Vlasov–Poisson equation in plasma physics, and are named after physicists Ira B. Bernstein, John M. Greene, and Martin D. Kruskal, who solved and published the exact solution for the one-dimensional case in 1957.

Many-body localization (MBL) is a dynamical phenomenon occurring in isolated many-body quantum systems. It is characterized by the system failing to reach thermal equilibrium, and retaining a memory of its initial condition in local observables for infinite times.

The Rotating wall technique is a method used to compress a single-component plasma confined in an electromagnetic trap. It is one of many scientific and technological applications that rely on storing charged particles in vacuum. This technique has found extensive use in improving the quality of these traps and in tailoring of both positron and antiproton plasmas for a variety of end uses.

Guy Laval is a French physicist, professor at the École polytechnique and member of the French Academy of Sciences.

Nathaniel Joseph Fisch is an American plasma physicist known for pioneering the excitation of electric currents in plasmas using electromagnetic waves, which was then used in tokamak experiments. This contributed to an increased understanding of plasma wave–particle interactions in the field for which he was awarded the James Clerk Maxwell Prize for Plasma Physics in 2005 and the Hannes Alfvén Prize in 2015.

John H. Malmberg American physicist

John Holmes Malmberg was an American plasma physicist and a professor at the University of California, San Diego. He was known for making the first experimental measurements of Landau damping of plasma waves in 1964, as well as for his research on non-neutral plasmas and the development of the Penning–Malmberg trap.

Penning–Malmberg trap

The Penning–Malmberg trap, named after Frans Penning and John Malmberg, is an electromagnetic device used to confine large numbers of charged particles of a single sign of charge. Much interest in Penning–Malmberg (PM) traps arises from the fact that if the density of particles is large and the temperature is low, the gas will become a single-component plasma. While confinement of electrically neutral plasmas is generally difficult, single-species plasmas can be confined for long times in PM traps. They are the method of choice to study a variety of plasma phenomena. They are also widely used to confine antiparticles such as positrons and antiprotons for use in studies of the properties of antimatter and interactions of antiparticles with matter.

Patrick Mora is a French theoretical plasma physicist who specializes in laser-plasma interactions. He was awarded the 2014 Hannes Alfvén Prize and 2019 Edward Teller Award for his contributions to the field of laser-plasma physics.

Toshiki Tajima is a Japanese theoretical plasma physicist known for pioneering the laser wakefield acceleration technique with John M. Dawson in 1979. The technique is used to accelerate particles in a plasma and was experimentally realized in 1994, for which Tajima received several awards such as the Nishina Memorial Prize (2006), the Enrico Fermi Prize (2015), the Robert R. Wilson Prize (2019), the Hannes Alfvén Prize (2019) and the Charles Hard Townes Award (2020).

Sergei Vladimirovich Bulanov, is a Russian physicist. He received the 1983 State Prize of the USSR, the 2016 Hannes Alfvén Prize for "contributions to the development of large-scale next-step devices in high-temperature plasma physics research", and the Order of Rising Sun with Gold Rays and Rosette in 2020.

Friedrich E. Wagner is a German physicist and emeritus professor who specializes in plasma physics. He was known to have discovered the high-confinement mode of magnetic confinement in fusion plasmas while working at the ASDEX tokamak in 1982. For this discovery and his subsequent contributions to fusion research, was awarded the John Dawson Award in 1987, the Hannes Alfvén Prize in 2007 and the Stern–Gerlach Medal in 2009.

References

  1. Beuhler, R. J.; Friedlander, G.; Friedman, L. (1989-09-18). "Cluster-impact fusion". Physical Review Letters. 63 (12): 1292–1295. Bibcode:1989PhRvL..63.1292B. doi:10.1103/PhysRevLett.63.1292. ISSN   0031-9007. PMID   10040525.
  2. Yang, S. N.; Cheng, Yi-Chen; Hwang, W.; Lee, Shyh-Tzong; Wu, C. (1991). "Cluster-Impact Fusion and Warm Atomic Plasma" (PDF). Chinese Journal of Physics. 29 (4): 385. Bibcode:1991ChJPh..29..385Y. S2CID   230385503. Archived (PDF) from the original on 2006-06-16. Retrieved 2021-04-21.
  3. Carraro, C.; Chen, B. Q.; Schramm, S.; Koonin, S. E. (1990-08-01). "Estimates of cluster-impact fusion yields". Physical Review A. 42 (3): 1379–1389. Bibcode:1990PhRvA..42.1379C. doi:10.1103/PhysRevA.42.1379. PMID   9904168.
  4. Rabinowitz, Mario (1990-05-20). "Cluster-Impact Fusion: New Physics or Experimental Error". Modern Physics Letters B. 04 (10): 665–671. Bibcode:1990MPLB....4..665R. doi:10.1142/S0217984990000830. ISSN   0217-9849.
  5. Thomson, Elizabeth A. (13 May 1992). "Cluster Fusion Is Illusion PFC Physicists Find". MIT News. Massachusetts Institute of Technology. Archived from the original on 2019-01-09. Retrieved 2021-04-21.
  6. Kim, Y. E.; Rabinowitz, M.; Bae, Y. K.; Chulick, G. S.; Rice, R. A. (1992). "Hot plasma shock-wave theory of cluster-impact fusion". AIP Conference Proceedings. Nikko (Japan): AIP. 250: 321–343. Bibcode:1992AIPC..250..321K. doi:10.1063/1.42021.
  7. Kim, Y. E.; Yoon, J.-H.; Rice, R. A.; Rabinowitz, M. (1992). "Cluster-impact fusion and effective deuteron temperature". Physical Review Letters. 68 (3): 373–376. arXiv: nucl-th/0304066 . Bibcode:1992PhRvL..68..373K. doi:10.1103/PhysRevLett.68.373. ISSN   0031-9007. PMID   10045875. S2CID   25205387.