Reversed-Field Pinch

The reversed field pinch (RFP) is a closely related configuration, since the plasma formation and ohmic heating are essentially identical to the tokamak. However, in the tokamak the average poloidal field is limited by stability requirements to approximately an order of magnitude smaller than the toroidal field, whereas the two are of similar magnitude in the RFP, both being typically less than 1 Tesla. 

The associations are the backbone of the fusion programme. They operate a number of fusion devices in their laboratories (see Table 7.7). Most of these fusion devices have been built along the tokamak principle, but there are also stellarators and reversed field pinches. And there are a number of facilities for technological development such as large superconducting-magnet-testing facilities. 

Reversed-Field-Pinch Reactor (Los Alamos Scientific Laboratory)... 

In closed-ended machines the plasma is twisted back on itself to form a torus, eliminating the end-loss problem. Since simple toroidal magnetic fields do not confine plasma against radial outward drift, more complex magnetic field geometries are required in closed systems. Of the eight concepts, two, EBT and the Reversed-Field-Pinch, are closed systems, the others are open. 

These two closed systems — EBT and Reversed-Field-Pinch — do not have the commonality exhibited by the Group I and II concepts and require separate discussion. 

In the Reversed-Field-Pinch, an initial toroidal magnetic field is trapped within a plasma which is heated ohmically by a toroidal plasma current (the... 

A major uncertainty regarding the Reversed-Field-Pinch is whether ohmic heating will be sufficient to achieve ignition. The most advanced experimental data base for the RFP is the British ZETA machine and the Italian ETA-BETA II, both of which have produced temperatures of the order of 100 eV, far from the thermonuclear regime, consistent with the small size of the devices so far constructed. 

In the same way we could fuel the field-reversed configuration. The transport scaling in the field-reversed configuration, is very different from that in other toroidal systems such as the reversed-field pinch , spheromak and tokamak. I say this because there is no shear in that system at all. Some instabilities are... 

Reversed-field pinch (RFP), e.g., the BODIN HBTX-1 A, the ROSTAGNI ETA BETA II devices (or the Los Alamos ZT-40). 

I n the case of the spheromak, these studies are also at a relatively low level, but I think there is more background information coming from the reversed-field pinch, for example, on what one might expect for transport and what kind of microstability might exist there. 

The plasma physics basis for CT reactor projections is derived from MHD stability theory and experimental observations of macrostability, and from postulated transport scaling or scaling of related devices (tokamak and diffuse, toroidal pinch). A central issue, on which different reactor projections can be based, centers on the observed macrostability of certain CT s (reversed field theta-pinch Toroidal apparent contradiction with MHD stability theory. Although the conflict may be resolved by inclusion of finite-ion-larmor radius (FLR) effects in the theory, scaling assumptions to reactor conditions may or may not invoke FLR. 

A moving ring CT reactor based on the FRC has been studied by Hagenson and Krakowski l and is summarized in Table 8. The ring is produced by a field-reversed 0-pinch with T 1.6 keV and compressed radially by 2.9 and axially by 1.9 to give T ... 

Table 8. C.T. Reactor Based on the Field-Reversed Theta Pinch ...

The reversed field 0 pinch with no toroidal field inside the plasmoid is a more advantageous reactor-oriented device than the spheromak, in some respects, since the plasma formation is... 

Fig. 13 The plasma formation scheme one is the Marshall gun approach and the other is reversed field theta pinch approach...

A variety of configurations has been considered,including spheromaks, field-reversed simple mirrors, relativistic ring systems, and field reversed theta pinches. Of these, the latter may be considered a direct descendant of the long linear systems approach indeed, experiments on FR0P date back to the 1960 s. In this method, a quasi-steady bias field is first established in the plasma tube. 

The first target considered here is a compact term (CT, used to be called short 6-pinch with a reversed field) somewhat along the lines descri-... 

The question of stability is crucial to any fusion scheme. The elongated reversed-field theta-pinch is observed to be stable for some time after formation but eventually succumbs to a rotational instability this is thought to be due to the plasma gaining angular momentum to compensate for the angular momentum carried away by escaping ions, and is therefore directly associated with plasma loss [22],... 

Fig. 3. Formation of a reversed-field theta pinch. THE ASTRON...

R. L. Hagenson and R. A. Krakowski, "A Compact Toroid Fusion Reactor (CTOR) Based on the Field Reversed Theta Pinch," Third IAEA Technical Committee and Workshop on Fusion Reactor Design and Technology, Tokyo (1981), to be published in the Proceedings. 

D. C. Barnes and C. E. Seyler, "Rotation of a Field Reversed Theta Pinch," Proceedings of the Sherwood Meeting, Tucson... 

Field-Reversed Theta-Pinch TRACT CTOR ... 

On the means of organization, 1 feel that you have listed these items as individual concepts, yet within these concepts there are groupings that should be brought together. I feel, for instance, that the field-reversed theta-pinch, the compact... 

Field-Reversed Theta-Pinch Compact Toroids Spheromak... 

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