Satellite spectra for helium-like titanium. Part II [report]

M. Bitter, K.W. Hill, M. Zarnstorff, S. von Goeler, R. Hulse, L.C. Johnson, N.R. Sauthoff, S. Sesnic, K.M. Young, M. Tavernier
1985 unpublished
DISCLAIMER This report was prepaid at an account of work sponsored by an agency of the United States Government Neither the United States Government DOT any agency thereof, nor any of their employees, mate any warranty, express or implied, or aainmes any legal liability or responsi bility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned right!. Refer ence herein to any rf
more » ... erein to any rf scjfic commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply it* endorsement, recom mendation, or favoring by the United States Government of any agency thereof. The views and opinions of authors expressed herein do not necesurily state or reflect those of the United States Government or any agency thereof. OTUriON OF .HiS DttlEfir IS DHIIHIIEQ 2 ABSTRACT KB X-ray spectra of helium-like titanium, Ti XXI, from Tokamak Fusion Test Reactor (TFTR) plasmas have been observed with a high resolution crystal spectrometer and have been used as a diagnostic of central plasma parameters. The data allow detailed comparison with recent theoretical predictions for the Ti XXI helium-like lines and the associated satellite spectrum in the wavelength range from 2.6000 to 2.6400 A, improved values for the excitation rate coefficients of the Tl XXI resonance line, the Intercomblnatlon ILn^s and the forbidden line, and new theoretical results on the wavelengths and transition probabilities fo* beryllium-like satellites due to transitions of the type Is 2 21nl' -1s2p21" nl" ' with n = 2-4 have been calculated. These data complement the theory given in an earlier paper (Part I). The experimental data are in excellent agreement with the theoretical predictions for the entire satellite spectrum. For plasr,.as with electron temperatures, T^, In the t;_;ige from 1.2 to 1.8 kaV. There Is also good general agreement between theory and eitpertment for the helium-like lines of Ti XXI. The observed intensity ratios of the intercorabination and forbidden lines to the resonance line are, however, larger than the predicted values by as much as an order of magnitude for electron temperatures T < 1.2 kev. Tills enhancement is due to lithlura-like titanium. The experimental data indicate that still other atomic processes, in addition to those considered by the theory, are Important for the excitation of these lines. The experimental results are documented to stimulate further analysis. The observed wavelengths agree to within an uncertainty of 0.S m^ with predictions frojn calculations which include relatlvistic and radiative corrections up to the third order in a. 3 The central ion temperature and the central toroidal rotation velocity of TFTR plasmas with ohmtc and neutral beam heating were obtained from Doppler measurements of the Ti XXI resonance line. Wavelength shifts of the apparent resonance line profile due to unresolved dieleotronlc satellites, which can ba Important corrections to Doppler shift (Measurements of plasma rotation velocities, have been determined as a function of the ion and electron temperatures and the fitting limits. Results on the electron temperature and the relative charge-state density of lithium-like and helium-like titanium were derived from the satellite spectrum and have been Interpreted with plasma modeling. These results are of Lnterest for the determination of the ionization equilibrium and the lrcpurity transport.
doi:10.2172/5216953 fatcat:f77zpckngfgnxh5tmvd4hpemt4