caa a22 4500 467916500 CHVBK 20180406152904.0 cr unu---uuuuu 170328e20060301xx s 000 0 eng 10.1134/S0020441206020138 doi (NATIONALLICENCE)springer-10.1134/S0020441206020138 A monitor of chord-averaged plasma density [Elektronische Daten] [V. Petrov, A. Petrov, A. Malyshev, V. Markov, A. Babarykin] A single-channel two-frequency chord-averaged density monitor for measuring the plasma density in tokamaks is described. The operating principle of the monitor is based on measuring the phase shift between two microwave signals at close frequencies transmitted through plasma along one and the same chord. At an appropriately chosen difference between these frequencies, the measured phase difference is <2π in the entire range of measured densities, thereby ensuring measurements without fringe jumps. The advantage of this method for measuring the delay time compared to the pulsed method consists in an increased sensitivity of measurements owing to the possibility of filtering signals at fairly high intermediate frequency (∼0.5-1 GHz). It is additionally possible to adjust the dynamic range of density measurements by selecting (optimizing) the frequency difference. The schematic diagram and the main performance characteristics of the monitor are presented. The results from laboratory tests of the monitor and those obtained with it on the T-11M facility are presented. The range of density measurements is 0.7 × 1012-0.7 × 1014 cm-3, the measurement accuracy is no worse than 1%, and the temporal resolution reaches 30 ns. Pleiades Publishing, Inc., 2006 52.55.Fa nationallicence 52.70.-m nationallicence 52.70.Gw nationallicence Petrov V. Russian State Scientific Center, Troitsk Institute of Innovative and Fusion Research, 142190, Troitsk, Moscow oblast, Russia aut Petrov A. Russian State Scientific Center, Troitsk Institute of Innovative and Fusion Research, 142190, Troitsk, Moscow oblast, Russia aut Malyshev A. Russian State Scientific Center, Troitsk Institute of Innovative and Fusion Research, 142190, Troitsk, Moscow oblast, Russia aut Markov V. Russian State Scientific Center, Troitsk Institute of Innovative and Fusion Research, 142190, Troitsk, Moscow oblast, Russia aut Babarykin A. Russian State Scientific Center, Troitsk Institute of Innovative and Fusion Research, 142190, Troitsk, Moscow oblast, Russia aut Instruments and Experimental Techniques Nauka/Interperiodica 49/2(2006-03-01), 238-243 0020-4412 49:2<238 2006 49 10786 https://doi.org/10.1134/S0020441206020138 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1134/S0020441206020138 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Petrov V. Russian State Scientific Center, Troitsk Institute of Innovative and Fusion Research, 142190, Troitsk, Moscow oblast, Russia aut NATIONALLICENCE 700 1- Petrov A. Russian State Scientific Center, Troitsk Institute of Innovative and Fusion Research, 142190, Troitsk, Moscow oblast, Russia aut NATIONALLICENCE 700 1- Malyshev A. Russian State Scientific Center, Troitsk Institute of Innovative and Fusion Research, 142190, Troitsk, Moscow oblast, Russia aut NATIONALLICENCE 700 1- Markov V. Russian State Scientific Center, Troitsk Institute of Innovative and Fusion Research, 142190, Troitsk, Moscow oblast, Russia aut NATIONALLICENCE 700 1- Babarykin A. Russian State Scientific Center, Troitsk Institute of Innovative and Fusion Research, 142190, Troitsk, Moscow oblast, Russia aut NATIONALLICENCE 773 0- Instruments and Experimental Techniques Nauka/Interperiodica 49/2(2006-03-01), 238-243 0020-4412 49:2<238 2006 49 10786 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer