Fabrication of the new poloidal field coils for DIII-D
The six new poloidal field coil assemblies manufactured by GA Technologies (GA) for DIII-D range in diameter from 3.4 to 5.3 m. Two of them are 55-turn field shaping coils. Each of the other four combines one turn of the ohmic heating coil and a 55-turn field shaping coil into a single unit encased in a stainless steel box beam. These four box beams, which provide support for the coils inside, are part of the overall coil and vacuum vessel support structure. They also serve as molds for vacuum impregnating the coils with epoxy. All coils are made of hollow, water-cooled copper conductor. The larger field shaping coils are designed for 20 kA, 3 sec rectangular current pulses with 40/sup 0/C temperature rise. The ohmic heating coil turns are capable of currents of up to 110 kA. The conductor is wrapped with Kapton and fiberglass tape; Kapton provides 1000 V/turn and 28 kV coil-to-ground insulation. The fiberglass acts as wick and reinforcement for the vacuum impregnated epoxy resin which bonds the coil together. The fabrication process is described in detail and illustrated. Critical operations were: manufacturing of the large box beams and molds, braze joining the conductor lengths and fittings, correctly placing the Kapton insulation, completing the mold and vacuum impregnation, and fitting the overwrapped coil with leads and water fittings in its mold (or box beam). Tools and setups used for special operations such as induction brazing, conductor winding, conductor bending, and vacuum impregnation are presented. The quality control procedures followed to guarantee sound brazed joints are explained. The electrical tests performed at several stages of fabrication, especially the 1000 V/turn impulse tests conducted before potting to facilitate fault detection and repair, are described.
- Research Organization:
- General Atomics Co., San Diego, CA (USA)
- DOE Contract Number:
- AC03-84ER51044
- OSTI ID:
- 6056706
- Report Number(s):
- GA-A-18161; CONF-851102-119; ON: DE87013379
- Resource Relation:
- Conference: 11. symposium on engineering problems in fusion research, Austin, TX, USA, 18 Nov 1985; Other Information: Paper copy only, copy does not permit microfiche production
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
DOUBLET REACTORS
MAGNET COILS
FABRICATION
TESTING
DESIGN
ELECTRIC CONDUCTORS
ELECTRICAL INSULATION
JOULE HEATING
ELECTRIC COILS
ELECTRIC HEATING
ELECTRICAL EQUIPMENT
EQUIPMENT
HEATING
PLASMA HEATING
RESISTANCE HEATING
THERMONUCLEAR REACTORS
TOKAMAK TYPE REACTORS
700202* - Fusion Power Plant Technology- Magnet Coils & Fields