A dual-band adaptor for infrared imaging

Ag, McLean; Jy, Ahn; Maingi, R.; Tk, Gray; Al, Roquemore

doi:10.1063/1.4717672

Cited by 30 publications

(21 citation statements)

References 20 publications

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“…Its detector is composed by 320 × 256 CdHgTe pixels, sensitive to mid-wave IR spectrum, nominally to photons with wavelength 3.7 ± 0.2 µm < λ < 4.8 ± 0.2 µm. In the present experiments, a long wavelength pass filter with cutoff at 4034 nm has been used, limiting the detector sensitivity to the range 4 µm < λ < 4.8 µm to avoid the detector saturation and the short wavelength IR part of the spectrum, dominated by molecular emission [18]. The acquisition rate is 200 fps and the integration time t int is 1.5 ms.…”

Section: Experimental Setup and Experiments Overviewmentioning

confidence: 99%

Understanding and suppressing the near scrape-off layer heat flux feature in inboard-limited plasmas in TCV

et al. 2017

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In inboard-limited plasmas, the Scrape-Off Layer (SOL) shows two regions: the near SOL, extending a few mm from the Last Closed Flux Surface (LCFS), characterized by a steep gradient of the parallel heat flux radial profile, and a far SOL, typically some cm wide, with flatter heat flux profiles. The physics of the near SOL is investigated in TCV with two series of experiments featuring deuterium and helium plasmas, in which the plasma current, density and elongation have been varied. The parallel heat flux profiles are measured on the limiter by means of infrared thermography. For the first time, the near SOL is reported to disappear for low plasma current or at high density, for values of the SOL collisionality ν * SOL corresponding to a conduction-limited regime. The power in the near SOL ∆P SOL is shown to decrease with the normalized Spitzer resistivity ν as ∆P SOL ∝ ν −1 . The floating potential profiles, measured at the limiter using flush-mounted Langmuir probes (LP), show the presence of non-ambipolar currents, and their relation to the presence of a velocity shear layer is discussed. The shearing rate is shown to strictly correlate with the power in the near SOL ∆P SOL , consistently with a recent theoretical model. Measurements of the near SOL on the Low Field Side (LFS) are performed using a reciprocating Langmuir probe (RP). The near SOL is reported to vanish simultaneously at the LFS and at the limiter. The near and far SOL widths are compared with the predictions from existing theoretical models, to which empirical corrections with resistivity and elongation are proposed.

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Section: Experimental Setup and Experiments Overviewmentioning

confidence: 99%

Understanding and suppressing the near scrape-off layer heat flux feature in inboard-limited plasmas in TCV

et al. 2017

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“…The IR camera has good sensitivity over a temperature range from 100 to 700 C, and can acquire images with a time resolution of less than a millisecond. 287 The first apparatus used to introduce lithium into NSTX were the lithium pellet injector (LPI) and lithium evaporators (LITERs). 177 Lithium was injected into NSTX discharges with the LPI, and the LITERs consisted of lithium-filled ovens with apertures that directed lithium vapor toward the lower NSTX divertor region.…”

Section: Plasma Facing Materials and Lithium Researchmentioning

confidence: 99%

Recent progress on spherical torus research

Ono

Kaita

2015

Physics of Plasmas

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The spherical torus or spherical tokamak (ST) is a member of the tokamak family with its aspect ratio (A = R0/a) reduced to A ∼ 1.5, well below the normal tokamak operating range of A ≥ 2.5. As the aspect ratio is reduced, the ideal tokamak beta β (radio of plasma to magnetic pressure) stability limit increases rapidly, approximately as β ∼ 1/A. The plasma current it can sustain for a given edge safety factor q-95 also increases rapidly. Because of the above, as well as the natural elongation κ, which makes its plasma shape appear spherical, the ST configuration can yield exceptionally high tokamak performance in a compact geometry. Due to its compactness and high performance, the ST configuration has various near term applications, including a compact fusion neutron source with low tritium consumption, in addition to its longer term goal of an attractive fusion energy power source. Since the start of the two mega-ampere class ST facilities in 2000, the National Spherical Torus Experiment in the United States and Mega Ampere Spherical Tokamak in UK, active ST research has been conducted worldwide. More than 16 ST research facilities operating during this period have achieved remarkable advances in all fusion science areas, involving fundamental fusion energy science as well as innovation. These results suggest exciting future prospects for ST research both near term and longer term. The present paper reviews the scientific progress made by the worldwide ST research community during this new mega-ampere-ST era.

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“…The IR camera installed on NSTX provides simultaneous measurements in two wavelength bands to compensate for emissivity changes in the lithium surface and acquires data at a frame rate of 1.6 kHz [3]. The dual-band IR camera is calibrated in situ using view of LLD surface for accurate temperature measurements.…”

Section: Elm Characteristics With Ir Cameramentioning

confidence: 99%

“…In addition, the power deposition profiles are obtained from dual-band IR camera measurements [3]. Initial analysis from the IR measurements was carried out to classify ELMs based on the timescales characterized by the rise time of the surface temperature [4].…”

Section: Introductionmentioning

confidence: 99%