Characteristics of the mode converter of Gyrotron FU CW GII radiating Gaussian beams in both the fundamental and second harmonic frequency bands

Tatematsu, Y.; Yamaguchi, Yuusuke; Idehara, T.; Kawase, Tatsuru; Ogawa, I.; Saito, T.; Fujiwara, Toshimichi

doi:10.1007/s10762-014-0072-1

Cited by 19 publications

(15 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Gyrotron FU CW GV was developed as the fifth gyrotron in the Gyrotron FU CW G-series [5][6][7][8][9]. A photograph of the gyrotron is shown in Fig.…”

Section: Gyrotron Fu Cw Gvmentioning

confidence: 99%

“…We therefore call the TE 10,6 mode the main mode. The mode converter consists of a helically cut launcher and four mirrors, similar to that used in the other gyrotrons of the Gyrotron FU CW G-series [5][6][7]. The cut angle of the helical launcher is related to the propagating EM wave mode.…”

Section: Gyrotron Fu Cw Gvmentioning

confidence: 99%

“…The angle θ is defined as cos −1 (m/ χ' m,n ), where χ' m,n is the n -th zero of the derivative of the m -th order Bessel function, J m ' (z), and the eigenvalue of the TE m,n mode. The quantity m/χ' m,n is an important factor that determines the direction and extension of a beam emitted from a Vlasov launcher [7]. In geometrical optics, the radius of the caustic surface of the EM wave is represented by R w cosθ in the waveguide [23,24], where R w is the waveguide radius.…”

Section: Gyrotron Fu Cw Gvmentioning

confidence: 99%

“…At the Research Center for Development of Far-Infrared Region, University of Fukui, Japan (FIR UF), a number of high-frequency gyrotrons operating at frequencies in ranges from subTHz to THz, including those of the Gyrotron FU-series, the Gyrotron FU CW-series, and the Gyrotron FU CW G-series, have been developed [1][2][3][4][5][6][7][8][9]. The gyrotrons of the FU CW G-series are equipped with an internal mode converter that converts the electromagnetic (EM) wave that is oscillating in the cavity into a Gaussian beam.…”

Section: Introductionmentioning

confidence: 99%

“…However, if FIR UF is to seek to become a center for joint research, it is preferable that it provides a gyrotron that radiates EM waves at various frequencies. In principle, it is possible that EM waves with various frequencies will oscillate in the gyrotron cavity if the cavity's magnetic field strength is changed appropriately [7,[17][18][19][20], and Gaussian-like beams have previously been observed with several cavity oscillation modes in a single gyrotron [7,19]. Therefore, the new multifrequency Gyrotron FU CW GV was planned.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Development of the Multifrequency Gyrotron FU CW GV with Gaussian Beam Output

Tatematsu¹,

Yamaguchi²,

Ichioka³

et al. 2015

J Infrared Milli Terahz Waves

Self Cite

View full text Add to dashboard Cite

Gyrotron FU CW GV has been developed as a multifrequency gyrotron for operation over the frequency range from 162 to 265 GHz at frequencies separated by steps of approximately 10 GHz. The oscillation modes were selected; the radii of the caustic surfaces for the electromagnetic waves of the modes had similar values in the waveguide, and it was therefore expected that these modes would be converted into Gaussian beams by a mode converter. In reality, more than ten modes oscillated and the Gaussian-like beams were radiated. A double-disk window with variable spacing maintains the transmittance through the window at a high level over a wide range of frequencies. Using this window, output powers of more than 1 kW were observed for almost all the expected modes.

show abstract

“…Gyrotron FU CW GV was developed as the fifth gyrotron in the Gyrotron FU CW G-series [5][6][7][8][9]. A photograph of the gyrotron is shown in Fig.…”

Section: Gyrotron Fu Cw Gvmentioning

confidence: 99%

Section: Gyrotron Fu Cw Gvmentioning

confidence: 99%

Section: Gyrotron Fu Cw Gvmentioning

confidence: 99%