Test of prototype ITER vacuum ultraviolet spectrometer and its application to impurity study in KSTAR plasmas

Abstract

Articles you may be interested inEdge impurity rotation profile measurement by using high-resolution ultraviolet/visible spectrometer on J-TEXTa) Rev. Sci. Instrum. 85, 11E423 (2014) To optimize the design of ITER vacuum ultraviolet (VUV) spectrometer, a prototype VUV spectrometer was developed. The sensitivity calibration curve of the spectrometer was calculated from the mirror reflectivity, the grating efficiency, and the detector efficiency. The calibration curve was consistent with the calibration points derived in the experiment using the calibrated hollow cathode lamp. For the application of the prototype ITER VUV spectrometer, the prototype spectrometer was installed at KSTAR, and various impurity emission lines could be measured. By analyzing about 100 shots, strong positive correlation between the O VI and the C IV emission intensities could be found.

Tungsten Data for Current and Future Uses in Fusion and Plasma Science

“…In particular, the ITER Core Imaging X-ray Spectrometer (CIXS), which is designed to measure the ion temperature and bulk plasma motion of ITER's plasma core, is being based on the X-ray emission of neon-like tungsten ions (W 64+ ) [6]. In addition, tungsten emission will be measured by extreme ultraviolet (EUV) and optical spectrometers to determine its concentration in the plasma and to assess power loss and the tungsten sputtering rate [7,8]. Moreover, tungsten is used on present-day tokamaks in preparation for ITER [9][10][11][12].…”

VUV spectroscopy in impurity injection experiments at KSTAR using prototype ITER VUV spectrometer

“…To calculate P, the illuminated area on the slit position was investigated from the ray-tracing calculation. 9 [ Figure 2(a)] Intensity distribution on the illuminated area is found to be uniform from this ray-tracing calculation. For this reason, P can be derived from the multiplication of the incident photon numbers on the slit position by (the slit area/the illuminated area), as shown in Fig.…”

“…The back-illuminated CCD provided efficiency of 35%-43% for the VUV light, while MCP showed an efficiency of 12% in the laboratory experiments. 9 The calibrated hollow cathode lamp of Fig. 2(a) was used for the intensity calibration of the spectrometer as described in Ref.…”

“…2(a) was used for the intensity calibration of the spectrometer as described in Ref. 9. The discharge condition of the hollow cathode lamp is I (DC current) = 1-2 A, DC voltage = 400-500 V with He or Ne as a discharge gas.…”

“…in the laboratory using emission lines from a hollow cathode lamp, which is an absolutely calibrated source via the electron storage ring BESSY in Berlin. [6][7][8][9] To evaluate the performance of the prototype spectrometer, it has been operated at KSTAR since the 2012 experimental campaign. From the measured spectra and the calibration curve, the line integrated emissivity profile of various impurity species has been derived.…”