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in creator/contributor: "Pacella, D."  
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Observation of anomalous Iron Ion Charge Distribution in FTU

Description: Iron coming from the poloidal limiter or the stainless steel vessel is an important intrinsic impurity in the FTU tokamak discharges, and X-ray and VUV spectroscopy provide useful information about the impurity behavior. The iron ion charge state distribution, as usual for tokamaks, is analyzed assuming a collisional radiative model and an anomalous perpendicular diffusion. In our experiment the iron ionization level depends, as it is expected, on central electron temperature (fig. 1), but the … more
Date: November 14, 2003
Creator: Finkenthal, M.; May, M.; Pacella, D.; Leigheb, M.; Zagorski, R.; Mattioli, M. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Soft X-ray Tangential Imaging of the NSTX Core Plasma by Means of a MPGD Pin-hole Camera

Description: A fast X-ray system based on a Micro Pattern Gas Detector has been used, for the first time, to investigate emission from the plasma core of the National Spherical Tokamak eXperiment (NSTX) at the Princeton Plasma Physics Laboratory. The results presented in this work demonstrate the capability of such a device to measure with a time resolution of the order of 1 ms the curvature and the elongation of the X-ray iso-emissivity contours, under various plasma conditions. Also, comparisons with the … more
Date: July 24, 2003
Creator: Pacella, D.; Leigheb, M.; Bellazzini, R.; Brez, A.; Finkenthal, M.; Stutman, D. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Empirical evaluation of the radiative cooling coefficient for krypton gas in the FTU plasma

Description: For future fusion reactors, a careful balance must be achieved between the cooling of the outer plasma via impurity radiation and the deleterious effects of inevitable core penetration by impurity ions. We have injected krypton gas into the Frascati Tokamak Upgrade (FTU) plasma. The measured visible bremsstrahlung and bolometric signals from krypton have been inverted and the resulting radial impurity density profile and power loss profile for krypton gas are extracted. Using the measured elect… more
Date: November 18, 1997
Creator: Fournier, K.B.; Pacella, D.; Gregory, B.C.; May, M.J.; Mazzitelli, G.; Gabellieri, L. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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ECE diagnostic of high temperature ECRH heated plasmas on FTU

Description: The Electron Cyclotron Emission (ECE) diagnostic on FTU tokamak is routinely performed with a Michelson interferometer with spectral range extending up to 1300 GHz. The diagnostic allowed accurate electron temperature measurements during the recent 140 Ghz Electron Cyclotron Resonance Heating (ECRH) experiments on FTU. Very accurate measurements have been performed on a wide range of electron temperatures and profile peaking. The ECE measurements have been compared with Thomson Scattering and w… more
Date: January 31, 2000
Creator: Zerbini, M.; Buratti, P.; Tudisco, O.; Giruzzi, G.; Bruschi, A.; Cirant, S. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Impurity transport studies of intrinsic Mo and injected Ge in high temperature ECRH heated FTU tokamak plasmas

Description: FTU plasmas reached a peak electron temperature up to 11 keV with ECRH heating during the current ramp up phase. For these plasmas X-ray emission of highly ionized molybdenum, the dominant intrinsic impurity, are presented in section II, and VUV spectra of injected germanium are presented in section III. In section IV the conclusions are discussed.
Date: June 1, 1999
Creator: Bracco, F.; Crisanti, M.; Finkenthal, M.; Fournier, K.; Gabellieri, G.; Granucci, G. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

The National Spherical Torus Experiment (NSTX) Research Program and Progress Towards High Beta, Long Pulse Operating Scenarios

Description: A major research goal of the National Spherical Torus Experiment is establishing long-pulse, high-beta, high-confinement operation and its physics basis. This research has been enabled by facility capabilities developed over the last two years, including neutral-beam (up to 7 MW) and high-harmonic fast-wave heating (up to 6 MW), toroidal fields up to 6 kG, plasma currents up to 1.5 MA, flexible shape control, and wall preparation techniques. These capabilities have enabled the generation of pla… more
Date: October 15, 2002
Creator: Synakowski, E. J.; Bell, M. G.; Bell, R. E.; Bigelow, T.; Bitter, M.; Blanchard, W. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Progress Towards High Performance, Steady-state Spherical Torus

Description: Research on the Spherical Torus (or Spherical Tokamak) is being pursued to explore the scientific benefits of modifying the field line structure from that in more moderate aspect-ratio devices, such as the conventional tokamak. The Spherical Tours (ST) experiments are being conducted in various U.S. research facilities including the MA-class National Spherical Torus Experiment (NSTX) at Princeton, and three medium-size ST research facilities: Pegasus at University of Wisconsin, HIT-II at Univer… more
Date: October 2, 2003
Creator: Ono, M.; Bell, M. G.; Bell, R. E.; Bigelow, T.; Bitter, M.; Blanchard, W. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Status and Plans for the National Spherical Torus Experimental Research Facility

Description: An overview of the research capabilities and the future plans on the MA-class National Spherical Torus Experiment (NSTX) at Princeton is presented. NSTX research is exploring the scientific benefits of modifying the field line structure from that in more conventional aspect ratio devices, such as the tokamak. The relevant scientific issues pursued on NSTX include energy confinement, MHD stability at high beta, non-inductive sustainment, solenoid-free start-up, and power and particle handling. I… more
Date: July 27, 2005
Creator: Columbia University
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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