Formation of field reversed configuration in FRP-1
Creators
- 1. Academia Sinica, Beijing, BJ (China). Inst. of Physics
Description
The formation of field-reversed configuration has been investigated experimentally in the Field Reversed Pinch Experiment, FRP - 1. The device is composed of a theta pinch coil of 56-cm in length and 12-cm in diameter, independently driven mirror coils and multipole field windings. The peak of the compression field is 6.8 KG with rise time of 3 μs. Two probes are inserted into the plasma, one is radially movable, positioned at the mid-plane of the theta coil for measuring the radial magnetic field profile, the other axially movable, located at r=O for observing the motion of X point on the symmetrical axis. The results indicate that the plasma begins to be radially compressed at about 1μS after the main field has been applied, which may be due to the fact that the preionization is not sufficient and that the main field is neither fast in rise time, nor high in field strength. In the meantine the flux of bias field trapped inside the plasma suffers a great loss. The plasma resistivity is observed to be 25 times higher than classical one during the rapid decay of the flux, but 3 times in the compression phase. The effect of mirror field at the ends of theta coil on the formation of field-reversed configuration has also been tested. In the absence of the mirror field the cylindrical plasma may extend out of coil ends, and may be torn in two, but the reproducibility is poor. In the presence of the mirror field the ends of the cylindrical plasma are well-defined within the coil and experience an axial contration. (author)
Availability note (English)
Available from the Library of Comissao Nacional de Energia Nuclear, RJ, Brazil.Abstract (Portuguese)
A formacao da configuracao de campo invertido tem sido investigada no experimento 'Pinch' de campo invertido, FRP-1. O dispositivo e composto de uma bobina teta pinch de 56 cm de comprimento e 12 cm de diametro, bobinas de espelhos diretores independentes e enrolamentos magneticos multipolo. O Pico do campo de compressao e 6.8 Kg com tempo de subida de 3 μs. Duas sondas sao inseridas dentro do plasma, um e movel radialmente, posicionado no plano medio da bobina teta para medida do perfil do campo magnetico radial, e outro movel axialmente, localizado em r=O para observacao do movimento do ponto X sobre o eixo simetrico. Os resultados indicam que o plasma comeca a ser radialmente comprimido em torno de 1 μs apos o campo principal ser aplicado, que pode ser devido ao fato de que a pre ionizacao nao e suficiente e que o campo principal nao e rapido no tempo de subida, nem alto na intensidade de campo. Entretanto o fluxo das linhas de campo aprisionadas dentro do plasma sofre uma grande perda. A resistividade do plasma observada e 25 vezes maior do que a classica durante o rapido decaimento do fluxo, mas 3 vezes maior na fase de compressao. O efeito do campo de espelhos nas bordas da bobina teta sobre a formacao da configuracao de campo invertido foi verificado. Na ausencia do campo de espelhos o plasma cilindrico pode se extender para fora das bordas da bobina e pode ser rompido em dois, mas a reproduzibilidade e pobre. Na presenca do campo de espelhos as bordas do plasma cilindrico sao bem definidas dentro da bobina e experimenta uma contracao axial. (M.C.K.)Additional details
Publishing Information
- Imprint Title
- Proceedings of the Energy Independence Conference: Fusion Energy and Plasma Physics
- Imprint Pagination
- 892 p.
- Journal Page Range
- p. 484-492.
Conference
- Title
- Fusion Energy and Plasma Physics.
- Acronym
- Energy Independence Conference
- Dates
- 17-21 Aug 1987.
- Place
- Rio de Janeiro, RJ (Brazil).
INIS
- Country of Publication
- Brazil
- Country of Input or Organization
- Brazil
- INIS RN
- 20050480
- Subject category
- S70: PLASMA PHYSICS AND FUSION TECHNOLOGY;
- Resource subtype / Literary indicator
- Conference, Non-conventional Literature
- Descriptors DEI
- FIELD-REVERSED THETA PINCH DEV; MAGNET COILS; MAGNETIC FIELDS; MAGNETIC MIRRORS; SPECIFICATIONS
- Descriptors DEC
- COMPACT TORUS; ELECTRIC COILS; ELECTRICAL EQUIPMENT; EQUIPMENT; OPEN PLASMA DEVICES; PINCH DEVICES; THERMONUCLEAR DEVICES; TORI