Author: Y. RA
Publisher:
ISBN:
Category :
Languages : en
Pages :

Get Book Here

Book Description

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 11

Get Book Here

Book Description
The graphite used for the limiter of the tokamak reactor produces carbon-containing molecular impurities as a result of the interactions with the edge plasma. The behavior of these molecular impurities has been studied using emission spectroscopy. The present study includes: finding molecular bands and atomic lines in the visible spectral range which can be used for the study of the molecular impurities, studying the breakup processes of the molecular impurities on their way from the source into the plasma, developing a spectroscopic diagnostic method for the absolute measurement of the molecular impurity flux resulting from graphite erosion. For these studies, carbon-containing molecules such as CH4, C2H2, C2H4, and CO2 were injected into the tokamak-boundary, like plasma generated by PISCES-A. The spectrograms of these gases were taken. Many useful bands and lines were determined from the spectrograms. The breakup processes of these gases were studied by observing the spatial profiles of the emission of the molecules and their radicals for different plasma conditions. For the absolute measurement of the eroded molecular impurity flux, the photon efficiency of the lines and bands were found by measuring the absolute number of the emitted photons and injected gas molecules. The chemical sputtering yield of graphite by hydrogen plasma was spectroscopically measured using the previously obtained photon efficiencies. It showed good agreement with results obtained by weight loss measurements. 16 refs., 7 figs., 1 tab.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 66

Get Book Here

Book Description
We have used the PISCES-A facility in order to study the behavior of carbon containing molecules in a representative plasma with parameters close to that of a tokamak boundary layer, CH4, C2H2, C2H4, CO, and CO2 molecules were introduced through a slit aperture into a helium plasma and the radiation from these due to electronic excitation was spectrographically recorded. The imaging of the plasma onto the entrance slit of a 1.33m McPherson optical spectrometer was chosen in such a way that simultaneous information about spectral and spatial distribution of the emission could be obtained by an attached photographic camera and an optical multichannel analyser (OMA). The recorded spectra show that many features in previously obtained spectra from limiters originate -- beside from hydrocarbons -- from carbonoxides, which seem to play a major role in the transport of carbon and oxygen. It was also possible to calibrate the radiation intensity of several molecular bands versus the known molecular influx so that an absolute determination of these fluxes from the wall of a fusion device could be done. Measurements of the attenuation of the individual species were carried out, which describe the penetration of carbon, oxygen, and hydrogen atoms into a discharge by taking into account individual steps in the molecular breakup process. 36 refs., 35 figs.

Author:
Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 548

Get Book Here

Book Description

Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 244

Get Book Here

Book Description

Author: Wolfgang Jacob
Publisher:
ISBN:
Category : Carbon composites
Languages : en
Pages : 150

Get Book Here

Book Description

Author:
Publisher:
ISBN:
Category : Engineering
Languages : en
Pages : 384

Get Book Here

Book Description

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

Get Book Here

Book Description
This paper discusses the following about the Pisces program: Major objectives of the program; Staff in the PISCES program at UCLA; Highlights in the program; Collaborations with other institutions; PISCES-A facility; PISCES-B facility; Fast scanning Langmuir probe; Omegatron mass spectrometer; Spectroscopic diagnostics; Data acquisition system; Redeposition effect on carbon chemical erosion; Erosion of carbon tokamakium from TFTR; Effect of boron-doping on carbon chemical erosion; Radiation enhanced sublimation of carbon; Surface analysis of TEXTOR titles; Spectroscopic analysis of carbon impurities; Biased limiter and divertor; Biased divertor channel; Gaseous divertor experiments; Presheath profile measurements; Particle transport in CCT tokamak; and Biased divertor experiments in CCT.

Author:
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 978

Get Book Here

Book Description

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 190

Get Book Here

Book Description