Plasma Position Measurements in a Tokamak with an Iron Core Transformer

• Published in: Japanese Journal of Applied Physics 2000-07, Vol.39 (7R), p.4188
• Main Authors: Gi-Chung Kwon, Gi-Chung Kwon, W. Choe, W. Choe, Jayhyun Kim, Jayhyun Kim, Hyo-Suk Yi, Hyo-Suk Yi, Sang-Jean Jeon, Sang-Jean Jeon, Songwhe Huh, Songwhe Huh, Hong-Young Chang, Hong-Young Chang, Duk-In Choi, Duk-In Choi
• Format: Article
• Language: English
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.39.4188

Two simple methods of estimating the plasma position in a large-aspect-ratio, low-β p tokamak with an iron core transformer are demonstrated: a magnetic diagnostic method and an optical method. The magnetic diagnostic method utilizes an array of magnetic pickup coils to measure the poloidal magnetic field produced by the plasma current. To include the effects of toroidicity and an iron core transformer, the correction factor was calculated with the magnetic material (or iron core) inside the calculation domain and incorporated in the analysis. The evolution of horizontal and vertical displacement of the plasma center obtained in this way is used to control the KAIST-Tokamak plasmas. To compare the plasma position estimated using the magnetic pickup coils, a simple optical method is also demonstrated on KAIST-TOKAMAK using a composite video signal from a charge-coupled device (CCD) camera. The two results are in good agreement.