Conceptual design of the tangentially viewing combined interferometer-polarimeter for ITER density measurements

Van Zeeland, M. A.; Boivin, R. L.; Brower, D. L.; Carlstrom, T. N.; Chavez, J. A.; Ding, W. X.; Feder, R.; Johnson, D.; Lin, L.; O'Neill, R. C.; Watts, C.
April 2013
Review of Scientific Instruments;Apr2013, Vol. 84 Issue 4, p043501
Academic Journal
One of the systems planned for the measurement of electron density in ITER is a multi-channel tangentially viewing combined interferometer-polarimeter (TIP). This work discusses the current status of the design, including a preliminary optical table layout, calibration options, error sources, and performance projections based on a CO2/CO laser system. In the current design, two-color interferometry is carried out at 10.59 μm and 5.42 μm and a separate polarimetry measurement of the plasma induced Faraday effect, utilizing the rotating wave technique, is made at 10.59 μm. The inclusion of polarimetry provides an independent measure of the electron density and can also be used to correct the conventional two-color interferometer for fringe skips at all densities, up to and beyond the Greenwald limit. The system features five chords with independent first mirrors to reduce risks associated with deposition, erosion, etc., and a common first wall hole to minimize penetration sizes. Simulations of performance for a projected ITER baseline discharge show the diagnostic will function as well as, or better than, comparable existing systems for feedback density control. Calculations also show that finite temperature effects will be significant in ITER even for moderate temperature plasmas and can lead to a significant underestimate of electron density. A secondary role TIP will fulfill is that of a density fluctuation diagnostic; using a toroidal Alfvén eigenmode as an example, simulations show TIP will be extremely robust in this capacity and potentially able to resolve coherent mode fluctuations with perturbed densities as low as δn/n ≈ 10-5.


Related Articles

  • Conceptual design of data acquisition and control system for two Rf driver based negative ion source for fusion R&D. Soni, Jigensh; Yadav, R. K.; Patel, A.; Gahlaut, A.; Mistry, H.; Parmar, K. G.; Mahesh, V.; Parmar, D.; Prajapati, B.; Singh, M. J.; Bandyopadhyay, M.; Bansal, G.; Pandya, K.; Chakraborty, A. // AIP Conference Proceedings;Feb2013, Vol. 1515 Issue 1, p284 

    Twin Source - An Inductively coupled two RF driver based 180 kW, 1 MHz negative ion source experimental setup is initiated at IPR, Gandhinagar, under Indian program, with the objective of understanding the physics and technology of multi-driver coupling. Twin Source [1] (TS) also provides an...

  • Progress and Present Status of ITER Cryoline System. Badgujar, S.; Bonneton, M.; Chalifour, M.; Forgeas, A.; Serio, L.; Sarkar, B.; Shah, N. // AIP Conference Proceedings;Jan2014, Vol. 1573, p848 

    The cryoline system at ITER forms a very complex network localized inside the Tokamak building, on a dedicated plant bridge and in cryoplant areas. The cooling power produced in the cryoplant is distributed via these lines with a total length of about 3.7 km and interconnecting all the cold...

  • Development of the ITER magnetic diagnostic set and specification. Vayakis, G.; Arshad, S.; Delhom, D.; Encheva, A.; Giacomin, T.; Jones, L.; Patel, K. M.; Pérez-Lasala, M.; Portales, M.; Prieto, D.; Sartori, F.; Simrock, S.; Snipes, J. A.; Udintsev, V. S.; Watts, C.; Winter, A.; Zabeo, L. // Review of Scientific Instruments;Oct2012, Vol. 83 Issue 10, p10D712 

    ITER magnetic diagnostics are now in their detailed design and R&D phase. They have passed their conceptual design reviews and a working diagnostic specification has been prepared aimed at the ITER project requirements. This paper highlights specific design progress, in particular, for the...

  • Distribution of the background gas in the MITICA accelerator. Sartori, E.; Dal Bello, S.; Serianni, G.; Sonato, P. // AIP Conference Proceedings;Feb2013, Vol. 1515 Issue 1, p121 

    MITICA is the ITER neutral beam test facility to be built in Padova for the generation of a 40A D- ion beam with a 16×5×16 array of 1280 beamlets accelerated to 1MV. The background gas pressure distribution and the particle flows inside MITICA accelerator are critical aspects for...

  • Thermal simulations of STRIKE tiles for the assessment of the CFC prototypes and of the configuration for SPIDER. Serianni, G.; De Muri, M.; Fasolo, D.; Pasqualotto, R.; Cervaro, V.; Dal Bello, S.; Palma, M. Dalla; Franchin, L.; Rizzolo, A.; Tollin, M. // AIP Conference Proceedings;Feb2013, Vol. 1515 Issue 1, p579 

    The ITER project requires additional heating via injection of neutral beams, provided by two injectors accelerating negative ions. To study and optimise negative ion production, the SPIDER prototype is under construction in Padova, whose beam has an energy of 100keV and a current of 50A. The...

  • Thomson Scattering for Core Plasma on DEMO. Mukhin, E. E.; Kurskiev, G. S.; Tolstyakov, S. Yu.; Kukushkin, A. B.; Andrew, P.; Bukreev, I. M.; Chernakov, P. V.; Kochergin, M. M.; Koval, A. N.; Litvinov, A. E.; Masyukevich, S. V.; Razdobarin, A. G.; Semenov, V. V.; Sdvizhenskii, P. A. // AIP Conference Proceedings;2014, Vol. 1612, p69 

    This paper describes the challenges of Thomson scattering implementation for core plasma on DEMO and evaluates the capability to measure extremely high electron temperature range 0.5-40keV. A number of solutions to be developed for ITER diagnostics are suggested in consideration of their...

  • Development of real-time rotating waveplate Stokes polarimeter using multi-order retardation for ITER poloidal polarimeter. Imazawa, R.; Kawano, Y.; Ono, T.; Itami, K. // Review of Scientific Instruments;Jan2016, Vol. 87 Issue 1, p1 

    The rotating waveplate Stokes polarimeter was developed for ITER (International Thermonuclear Experimental Reactor) poloidal polarimeter. The generalized model of the rotating waveplate Stokes polarimeter and the algorithm suitable for real-time field-programmable gate array (FPGA) processing...

  • Diagnostics and Required R&D for Control of Demo Grade Plasmas. Park, Hyeon K. // AIP Conference Proceedings;2014, Vol. 1612, p3 

    Even if the diagnostics of ITER performs as expected, installation and operation of the diagnostic systems in Demo device will be much harsher than those of the present ITER device. In order to operate the Demo grade plasmas, which may have a higher beta limit, safely with very limited number of...

  • Modelling of edge localised modes and edge localised mode control. Huijsmans, G. T. A.; Chang, C. S.; Ferraro, N.; Sugiyama, L.; Waelbroeck, F.; Xu, X. Q.; Loarte, A.; Futatani, S. // Physics of Plasmas;2015, Vol. 22 Issue 2, p1 

    Edge Localised Modes (ELMs) in ITER Q10 H-mode plasmas are likely to lead to large transient heat loads to the divertor. To avoid an ELM induced reduction of the divertor lifetime, the large ELM energy losses need to be controlled. In ITER, ELM control is foreseen using magnetic field...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics