Electron cyclotron heating and diagnostics of plasma at the second harmonic in the GDT device

Gospodchikov, E. D.; Smolyakova, O. B.; Solomakhin, A. L.; Shalashov, A. G.

doi:10.1051/epjconf/201714903023

Cited by 4 publications

(2 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…With the electron temperature of 200-600 eV, the cyclotron emission of the bulk plasma is virtually negligible, 𝑇 ECE /𝑇 CTS 10 −3 , if the main contribution comes from the thermal ECE at the fundamental harmonic generated far from the CTS zone [34] Frequency (GHz) level is about 10-30 eV at 55-60 GHz. The enhanced ECE level may be explained as a spontaneous emission of high-energy electrons arising due to interaction of high-power gyrotron radiation with the plasma [40,45,46]. This radiation is maximal near the fundamental and second cyclotron harmonics, where the measured ECE level of more than 1 keV [46], but this zone is located 3 m far from the CTS plane, thus we receive a much weaker signal after several wall reflections.…”

Section: Jinst 16 P07007mentioning

confidence: 76%

See 1 more Smart Citation

Development of fast-ion collective Thomson scattering diagnostics for the GDT experiment

Shalashov¹,

Gospodchikov²,

Khusainov³

et al. 2021

J. Inst.

View full text Add to dashboard Cite

In this paper, we describe hardware developed for the collective Thomson scattering (CTS) diagnostic for the large open magnetic trap GDT (Budker Institute, Russia) used in fusion researches. The diagnostic utilizes 400 kW/54.5 GHz gyrotron as a source of probe radiation and is aimed at the reconstruction of fast ion distributions over transverse and longitudinal velocities driven by high-power neutral beam injection. Formation and manipulation of the probe beam and collection of the scattered microwave radiation are done with large-aperture quasi-optical mirror systems. The receiving complex consists of two identical channels for simultaneous detection of scattering in two complement geometries. Each channel includes a highly sensitive radiometer/spectrum analyzer with the band of 54.470 ± 0.550 GHz, the noise temperature of 0.35 eV, the sensitivity less than 0.025 eV, the frequency/time resolution of 5-50 MHz/10 μs, and narrow-band notch filter providing at least −40 dB rejection in the band of 25 MHz with a central frequency tunable in 54.470 ± 0.050 GHz for protection of the input RF circuit from a backlight of powerful gyrotron radiation. K: Nuclear instruments and methods for hot plasma diagnostics; Microwave radiometers

show abstract

Section: Jinst 16 P07007mentioning

confidence: 76%

“…Our present experimental setup does not allow reliable measurements of 10-30 eV signals exactly in the CTS band. However, knowing that the suprathermal ECE lines in GDT conditions have typical width of a few GHz [45], we may extrapolate our measurements for 55-60 GHz to the band of 54.5-55 GHz assuming a flat ECE spectrum.…”

Section: Jinst 16 P07007mentioning

confidence: 98%