| Автор | D.G. Whyte |
| Автор | M.R. Wade |
| Автор | D.F. Finkenthal |
| Автор | K.H. Burrell |
| Автор | P. Monier-Garbet |
| Автор | B.W. Rice |
| Автор | D.P. Schissel |
| Автор | W.P. West |
| Автор | R.D. Wood |
| Дата выпуска | 1998-03-01 |
| dc.description | Charge exchange recombination (CER) spectroscopy in the visible spectrum is used to measure the radial ion density distribution of impurities in the core plasma of DIII-D. The radial profile of the effective ionic charge, Z<sub>eff</sub>(r), is subsequently calculated from the impurity densities and the electron density of the plasma. The CER measured radial distributions rely on a calculated neutral beam attenuation radial profile, which is confirmed by independent measurement. This technique, which determines the deuterium density of the neutral beam by coupling measured beam D<sub>α</sub> emissions with a time dependent collisional radiative calculation, will be described. The CER derived absolute density/concentrations of carbon are verified by comparisons with the spectrometrically measured visible bremsstrahlung emission of the core plasma, which is proportional to Z<sub>eff</sub>. Conversely, the seeded neon concentration is overestimated by a factor of 1.7 by CER. This correction is shown to be caused by the enhanced direct capture into the upper level of the measured visible neon transition (Ne X n = 11 to 10, 5249 Å) from excited (n = 2) beam atoms. Owing to several problems, including line radiation contamination of the spectral region of the diagnostic, the standard Z<sub>eff</sub>(r) derived from inversion of line integrated visible bremsstrahlung emissions does not provide reliable profiles, but rather a measure of the average impurity content. The Z<sub>eff</sub> profiles are found to vary considerably in shape and magnitude over different operational regimes, confirming the need for accurate profiles. |
| Формат | application.pdf |
| Издатель | Institute of Physics Publishing |
| Название | Measurement and verification of z<sub>eff</sub> radial profiles using charge exchange recombination spectroscopy on DIII-D |
| Тип | paper |
| DOI | 10.1088/0029-5515/38/3/305 |
| Electronic ISSN | 1741-4326 |
| Print ISSN | 0029-5515 |
| Журнал | Nuclear Fusion |
| Том | 38 |
| Первая страница | 387 |
| Последняя страница | 398 |
| Аффилиация | D.G. Whyte; General Atomics, San Diego, California, United States of America |
| Аффилиация | M.R. Wade; General Atomics, San Diego, California, United States of America |
| Аффилиация | D.F. Finkenthal; General Atomics, San Diego, California, United States of America |
| Аффилиация | K.H. Burrell; General Atomics, San Diego, California, United States of America |
| Аффилиация | P. Monier-Garbet; General Atomics, San Diego, California, United States of America |
| Аффилиация | B.W. Rice; General Atomics, San Diego, California, United States of America |
| Аффилиация | D.P. Schissel; General Atomics, San Diego, California, United States of America |
| Аффилиация | W.P. West; General Atomics, San Diego, California, United States of America |
| Аффилиация | R.D. Wood; General Atomics, San Diego, California, United States of America |
| Выпуск | 3 |
