Contraction of <i>Z</i> pinches actuated by radiation losses

Shearer, J. W.

doi:10.1063/1.861627

Cited by 91 publications

(34 citation statements)

References 6 publications

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“…To take into account all the energy losses and energy deposition processes is a task for a 2D MHD simulation and cannot be attempted here (**).Restricting ourselves to only bremsstrahlung and Joule's heating below 5.107 K we know that, in most cases, the radius a will grow until the Pease-Braginski current Ip~ is reached, after which there follows a radiation collapse [7] described by …”

Section: ( Ns Ll/z Cv~ (Ma) In] Kmentioning

confidence: 97%

A micro Z-pinch as a spark of an axial detonation

Linhart¹

1994

Nuov Cim D

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Summary. --In order that a Z-pinch in a DT plasma could spark off an axial nuclear detonation wave severe conditions on space and time concentration of electromagnetic energy must be satisfied. Such energy compression could be achieved by a magnetic-field compressor (MFC) in which a fast liner compresses an azimuthal field (B~) of a micro Z-pinch. The driver of the MFC could be either a heavy-ion beam or an explosive magnetic-field generator (EMG) destroyed at each shot. In conclusion, some of the major problems associated with this approach to ICF are outlined.PACS 52.55.Ez-Pinch effect and pinch devices (e.g., Z-pinches and theta pinches). PACS 52.55.Pi -Confinement in fusion experiments (including a-particle effects, scaling laws, etc.).

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Section: ( Ns Ll/z Cv~ (Ma) In] Kmentioning

confidence: 97%

A micro Z-pinch as a spark of an axial detonation

Linhart¹

1994

Nuov Cim D

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“…This is not obvious since the current in heating the filament will lead to a plasma corona surrounding the filament and which can have a radius much larger than the radius of the filament. However, as it has been shown by several authors [3,4], the bremsstrahlungslosses in a high-Z plasma, as it is realized here, can be so large that they cause rapid shrinking of the plasma corona down to the very small dimensions as required.…”

mentioning

confidence: 90%

Acceleration of Filamentary Macroparticles to Very Large Velocities in High Voltage Diodes

Winterberg

1978

Zeitschrift Für Naturforschung A

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An attempt is made to explain the observed very large velocities of macroscopic particles in pulsed high voltage diodes. It is assumed that the macroscopic particle has the shape of a filament which is pulled out of the anode surface by electrostatic forces. It is furthermore assumed that a vacuum spark will originate from the tip of this filament If the current of the spark discharge is very large and the filament radius sufficiently small, it will be held together by a large magnetic field. This large magnetic field then also permits the filament to become highly charged and it is shown that this large charge in conjunction with the applied large diode field can explain the observed very high velocities.It has been observed in rapidly rising high voltage diodes that specks of matter, after torn off from the anode surface, can impact with very high velocities on the cathode [1]. According to these experiments impact velocities of macroscopic particles up to ~ 10 9 cm/sec were observed. Unfortunately, no analysis of the cratering process was done from which the mass could have been estimated. The understanding of this phenomenon may be of considerable importance, since macroscopic objects attaining these large velocities and having sufficiently large masses could be used to make large scale nuclear reactions and perhaps ignite thermonuclear microexplosions.We first show that a simple interpretation fails to explain the observed phenomenon. In this simple interpretation a speck of matter, assumed spherical in shape and attached to the anode is first charged up to a high potential. As a result of the large electrostatic forces acting on this speck, it is then torn off from the anode surface and accelerated towards the cathode. If a speck of matter with mass m acquires the charge q, and if the diode voltage is V (esu), its final velocity v is determined by i mv 2 = qV.(1)Now, the maximum charge the speck can attain depends on its tensile strength a by the circumstance that the surface electric field is limited to values for which E 2 /S7i

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“…If the implosion is non-isentropic, shock waves will lead to overheating, and for currents below the Pease-Braginskii current resistive overheating sets in. The importance of exceeding the Pease-Braginskii current, which for a hydrogen plasma is ~ 1.7 x 106 [A], was already recognized by Shearer [4].…”

Section: Introductionmentioning

confidence: 97%

Implosion of the superpinch

Winterberg

1978

Z Physik A

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It is shown that a programmed fast rising current, making an excursion in excess of the Pease-Braginskii current, can isentropically compress a thermonuclear plasma to very high densities. Such a dynamic superpinch can satisfy the Lawson criterion for the D Tthermonuclear reaction. The pinch current has to be driven by a large fast rising multimegavolt pulse power source. It is anticipated that electric pulse power sources employing both the magnetic insulation and double disc principles can satisfy the needed requirements in high voltages large currents and short discharge times.

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Contraction of Z pinches actuated by radiation losses

Abstract: An equilibrium model of the radial motion of Z pinches is developed, based on the Bennett relation, radiation losses, and Ohmic heating. The highly localized x-ray sources observed in some plasma focus experiments can be explained by the model.

Cited by 91 publications

References 6 publications

A micro Z-pinch as a spark of an axial detonation

A micro Z-pinch as a spark of an axial detonation

Acceleration of Filamentary Macroparticles to Very Large Velocities in High Voltage Diodes

Implosion of the superpinch

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