Prospects for determining the D-T isotopic ratio in the JET plasma by spectroscopic observation of a Penning discharge
Simulated spectra of the Balmer D(alpha) and T(alpha) lines from a Penning discharge in a D-T mixture have been used to assess the potential of the technique in determining the isotopic ratio in the Joint European Torus (JET) divertor neutral gas. Results from measurements in a D-H mixture, with a spectrometer and charge coupled device (CCD) camera as detector, were used as starting point. The results of repeated multi-Gaussian fits to synthetic spectra, to which random noise had been added, were analysed to evaluate the errors in determining the T/D ratio, for a range of tritium concentrations. It is concluded that T/D ratios of 0.5% can be measured, with an uncertainty of approximately +/- 50% and time resolution 3 s, whilst for a 1:1 D-T mixture an uncertainty of +/- 10% is achievable with time resolution approximately 100 ms. The equipment to make this measurement during JET D-T operation has been installed.
Bibliographic Reference: Report: Jet-R (97) 08 EN (1997) 9pp.
Availability: Available from the Publications Officer, JET Joint Undertaking, Abingdon, Oxon OX14 3EA (GB)
Record Number: 199711263 / Last updated on: 1997-10-10
Original language: en
Available languages: en