Tritium concentration measurements in the Joint European Torus divertor by optical spectroscopy of a Penning discharge
Journal Article
·
· Review of Scientific Instruments
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)
- JET Joint Undertaking, Abingdon, Oxfordshire (United Kingdom)
- Institute for Plasma Research, Bhat, Gandhinagar 382-428 (India)
Obtaining precision measurements of the relative concentrations of hydrogen, deuterium, tritium, and helium in the divertor of a tokamak is an important task for nuclear fusion research. Control of the deuterium{endash}tritium isotopic ratio while limiting the helium ash content in a fusion plasma are key factors for optimizing the fuel burn in a fusion reactor, like the International Tokamak Experimental Reactor. A diagnostic technique has been developed to measure the deuterium{endash}tritium isotopic ratio in the divertor of the Joint European Torus with a species-selective Penning vacuum gauge. The Penning discharge provides a source of electrons to excite the neutral hydrogen isotopes in the pumping duct. Subsequently, the visible light from the hydrogen isotopes is collected in an optical fiber bundle, transferred away from the tokamak into a low radiation background area, and analyzed in a high resolution Czerny{endash}Turner spectrometer, which is equipped with a fast charge coupled device camera for optical detection. The intensity of the observed line emission (D{sub {alpha}}{minus}6561.03thinsp{Angstrom} and T{sub {alpha}}{minus}6560.44thinsp{Angstrom}) is directly proportional to the partial pressure of each gas found in the divertor. The line intensity of each isotope is calibrated as a function of pressure. The ratio of the line intensities thus provides a direct measurement of the deuterium{endash}tritium isotopic ratio. The lower limit for the determination of the deuterium{endash}tritium isotopic ratio is about 0.5{percent}. The applicable pressure range for this system is from 10{sup {minus}5} to a few times 10{sup {minus}3}thinspmbar. {copyright} {ital 1999 American Institute of Physics.}
- OSTI ID:
- 295616
- Report Number(s):
- CONF-980605--
- Journal Information:
- Review of Scientific Instruments, Journal Name: Review of Scientific Instruments Journal Issue: 1 Vol. 70; ISSN 0034-6748; ISSN RSINAK
- Country of Publication:
- United States
- Language:
- English
Similar Records
Tritium concentration measurements in the JET divertor by optical spectroscopy of a Penning discharge
Simultaneous H/D/T and 3He/4He absolute concentration measurements with an optical Penning gauge on JET
Electron Density Measurements in the National Spherical Torus Experiment Detached Divertor Region Using Stark Broadening of Deuterium Infrared Paschen Emission Lines
Technical Report
·
Mon Jun 01 00:00:00 EDT 1998
·
OSTI ID:658453
Simultaneous H/D/T and 3He/4He absolute concentration measurements with an optical Penning gauge on JET
Conference
·
Wed Sep 01 00:00:00 EDT 2021
·
OSTI ID:1813243
Electron Density Measurements in the National Spherical Torus Experiment Detached Divertor Region Using Stark Broadening of Deuterium Infrared Paschen Emission Lines
Journal Article
·
Fri Apr 27 00:00:00 EDT 2007
· Review of Scientific Instruments
·
OSTI ID:940885