Performance and data analysis aspects of the new DIII-D monostatic profile reflectometer system
- Univ. of California, Los Angeles, CA (United States)
A new frequency-modulated (FMCW) profile reflectometer system, featuring a monostatic antenna geometry (using one microwave antenna for both launch and receive), has been installed on the DIII-D tokamak, providing a first experimental test of this measurement approach for profile reflectometry. Significant features of the new system are briefly described in this paper, including the new monostatic arrangement, use of overmoded, broadband transmission waveguide, and dual-polarization combination/demultiplexing. Updated data processing and analysis, and in-service performance aspects of the new monostatic profile reflectometer system are also presented. By using a raytracing code (GENRAY) to determine the approximate trajectory of the probe beam, the electron density (ne) profile can be successfully reconstructed with L-mode plasmas vertically shifted by more than 10 cm off the vessel midplane. Specifically, it is demonstrated that the new system has a capability to measure ne profiles with plasma vertical offsets of up to ±17 cm. Furthermore, examples are also presented of accurate, high time and spatial resolution density profile measurements made over a wide range of DIII-D conditions, e.g. the measured temporal evolution of the density profile across an L-H transition.
- Research Organization:
- General Atomics, San Diego, CA (United States)
- Sponsoring Organization:
- USDOE Office of Nuclear Energy (NE)
- Grant/Contract Number:
- FC02-04ER54698
- OSTI ID:
- 1352931
- Journal Information:
- Review of Scientific Instruments, Vol. 85, Issue 11; ISSN 0034-6748
- Publisher:
- American Institute of Physics (AIP)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
2D imaging of helium ion velocity in the DIII-D divertor
|
journal | May 2018 |
A free-standing wire scattering technique to monitor calibration variations of the DIII-D density profile reflectometer
|
journal | October 2018 |
L – H transition trigger physics in ITER-similar plasmas with applied n = 3 magnetic perturbations
|
journal | September 2019 |
Similar Records
Core reflectometer density profile measurements on DIII-D
Preliminary design overview and performance assessment of the ITER low-field side reflectometer