Electromagnetic Analysis And Engineering Design Of The OH Coil For NSTX

This paper deals with the electromagnetic analysis and engineering design of the OH coil for NSTX. In calculating the magnetic distribution and the inductance of OH coil, Bill-Surf equation and elliptic integral is used to simplify the calculation, Then , turn processes of calculation into language for computers , and a right result has been received after a series of adjustments. In engineering design , the 962 turn OH coil system consists of four layers which are wound"double-wire", forming a total of 8 sub-windings which are electrically connected in series, but which are water cooled in parallel by 8 individual cooling paths. The conductor temperature and calculation of the velocity of cooling water flow are also given in this paper. In the OH coil the maximum voltages which appears between turns in the same layer is as high as 1.5kV. As the OH coil is very long and can not be placed in the vacuum pressure vessel, a new VPI processing technology is adopted for electrical Insulation of the OH coil. The coil after vacuum pressure impregnation has the same electrical and mechanical properties. Furthermore, the paper also show the fabrication of the OH Layer to Layer Joints ,which is the crucial feature of the OH coil.