S-1 SPHEROMAK

A schematic diagram of the S 1 spheromak is given in Fig. The vacuum vessel has a major radius of 1.5m and an oblate... 

Fig. 26 The toroidal field pattern behavior in Proto S-1 spheromak. Ref. [30a]...

We discuss (1) the theoretical analysis of the spheromak, (recent theoretical studies are summarized and a comparison is made with other approaches), and (2) a spheromak plasma formation scheme. One of the difficult aspects of spheromak research is to produce a toroidal plasma in the absence of coils down the axis of rotational symmetry. A novel plasma formation scheme has been developed at PPPL to create a toroidal plasma by using a flux generating core technique. This formation scheme has been optimized with the assistance of resistive MHD computer codes. The parameters of the S-1 device, now under construction, were determined with various theoretical aids. 

Recently a email device (1/6 scale of S-1) has successfully produced a spheromak plasma using this scheme. 

Recently a quasistatic means of producing a Spheromak has been studied in the Proto S-1 experiment at PPL, Princeton. 

The parameters of Proto S-1 and the S-l device under construction (see Fig. 12) are shown in Table 2. The objective of this approach is to inductively form a Spheromak on a timescale intermediate to a resistive diffusion time and a sound transit time. A vacuum poloidal field is established by toroidal currents in a supported ring (see Fig. 13). A toroidal solenoid inside the ring is switched off to provide a poloidal EMF while the toroidal ring current is driven down forcing reconnection. The resulting plasma currents form an isolated Spheromak as shown in Fig. 13. The process is an inductive version of the direct-coupled process employed with guns. 

Experiments in Proto S-1 have produced Spheromak rings with parameters given in Table 2. Some evidence for nonsymmetric instability has been obtained ... 

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