Miscellaneous data on materials for millimetre and submillimetre optics

Lamb, James W.

doi:10.1007/bf02069487

Cited by 313 publications

(201 citation statements)

References 53 publications

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“…For small-diameter test rods, the ε error upon formula (3) is insufficient and allows permittivity assessments of a thin rod inside the ORC without a rigorous theory. Also, ε measuring results for polyamide, Teflon, polyethylene and quartz are shown, demonstrating a good agreement with those from other authors [1,13].…”

Section: Experimental Prototype Of the Orc With A Dielectric Insertsupporting

confidence: 88%

An Open Resonance Cell for Millimeter Wave Dielectrometer Applications

Miroshnichenko¹,

Melezhik²,

Senkevich³

2008

PIER M

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Abstract-An open resonance cell (ORC) with finite-length cylindrical mirrors is suggested for making absolute measurements of complex permittivity in the case of stretched cylindrical specimens or liquid dielectrics in cylindrical containers. For H-polarization, we report ORC features simulated in rigorous electromagnetic terms using a twodimensional (2-D) model of an open resonator with cylindrical mirrors and a dielectric test rod inserted. On this basis, the ORC laboratory prototype with finite-length mirrors was built. The measurements of dielectric test rods were performed in the 10 mm wave band. In the studies of dielectric materials, E-polarized modes of the cylindricalmirror ORC demonstrate some specific features, which are discussed, too.

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Section: Experimental Prototype Of the Orc With A Dielectric Insertsupporting

confidence: 88%

An Open Resonance Cell for Millimeter Wave Dielectrometer Applications

Miroshnichenko¹,

Melezhik²,

Senkevich³

2008

PIER M

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“…At 250 GHz, fused quartz has an index of refraction of 1.955 [11] and for an incidence angle of 45° has a reflection minimum for a thickness of approximately 1 mm. Common microscope slides with this thickness and sufficient area (25 × 50 mm) to cover a 22-mm aperture at 45° are readily available and were used in the current experiments.…”

Section: B Directional Couplermentioning

confidence: 99%

Corrugated waveguide and directional coupler for CW 250-GHz gyrotron DNP experiments

Woskov

Bajaj

Hornstein

et al. 2005

IEEE Trans. Microwave Theory Techn.

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A 250-GHz corrugated transmission line with a directional coupler for forward and backward power monitoring has been constructed and tested for use with a 25-W continuous-wave gyrotron for dynamic nuclear polarization (DNP) experiments. The main corrugated line (22-mm internal diameter, 2.4-m long) connects the gyrotron output to the DNP probe input. The directional coupler, inserted approximately midway, is a four-port crossed waveguide beamsplitter design. Two beamsplitters, a quartz plate and ten-wire array, were tested with output coupling of 2.5% (−16 dB) at 250.6 GHz and 1.6% (−18 dB), respectively. A pair of mirrors in the DNP probe transferred the gyrotron beam from the 22-mm waveguide to an 8-mm helically corrugated waveguide for transmission through the final 0.58-m distance inside the NMR magnet to the sample. The transmission-line components were all cold tested with a 248 ± 4-GHz radiometer. A total insertion loss of 0.8 dB was achieved for HE 11 -mode propagation from the gyrotron to the sample with only 1% insertion loss for the 22-mm-diameter waveguide. A clean Gaussian gyrotron beam at the waveguide output and reliable forward power monitoring were achieved for many hours of continuous operation.

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“…Due to the geometry of the setup, this results in a reduction of the ECRH stray radiation at the detector by a factor of 120. An additional ∼20% absorption can be expected within the lens system (loss tangent values at 140 GHz have been reported by various authors for many UV/vis./IR optical materials [11][12][13] ). The remaining ECRH stray radiation at the detector amounts to ∼10 mW distributed over 1280 × 1024 pixels or 0.007 μW/pixel.…”

Section: B Ir/visible Long Pulse Compatible Divertor Observation Endmentioning

confidence: 74%

Status of the diagnostics development for the first operation phase of the stellarator Wendelstein 7-X

König

Biel

Biedermann

et al. 2014

Review of Scientific Instruments

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Articles you may be interested inDiagnostics development for quasi-steady-state operation of the Wendelstein 7-X stellarator (invited)a) Rev. Sci. Instrum. 83, 10D730 (2012) An overview of the diagnostics which are essential for the first operational phase of Wendelstein 7-X and the set of diagnostics expected to be ready for operation at this time are presented. The ongoing investigations of how to cope with high levels of stray Electron Cyclotron Resonance Heating (ECRH) radiation in the ultraviolet (UV)/visible/infrared (IR) optical diagnostics are described.

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Miscellaneous data on materials for millimetre and submillimetre optics

Cited by 313 publications

References 53 publications

An Open Resonance Cell for Millimeter Wave Dielectrometer Applications

An Open Resonance Cell for Millimeter Wave Dielectrometer Applications

Corrugated waveguide and directional coupler for CW 250-GHz gyrotron DNP experiments

Status of the diagnostics development for the first operation phase of the stellarator Wendelstein 7-X

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