Enhancement of the JET edge LIDAR Thomson scattering diagnostic with ultrafast detectors
- Euratom/UKAEA Fusion Association, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom)
- Consorzio RFX, Associazione Euratom, ENEA Sulla Fusione, Corso Stati Uniti 4, I-35127 Padova (Italy)
The edge light detection and ranging (LIDAR) Thomson scattering diagnostic at the Joint European Torus fusion experiment uses a 3 J ruby laser to measure the electron density and temperature profile at the plasma edge. The original system used a 1 GHz digitizer and detectors with response times of {approx_equal}650 ps and effective quantum efficiencies <7%. This system has recently been enhanced with the installation of a new 8 GHz digitizer and four new ultrafast GaAsP microchannel plate photomultiplier tube detectors with response times of <300 ps and effective quantum efficiencies in the range of {approx}13%-20% (averaged over {lambda}=500-700 nm). This upgrade has enabled the spatial resolution to be reduced to {approx}6.3 cm along the laser line of sight for a laser pulse of 300 ps full width at half maximum, which is close to the requirements for the ITER core LIDAR. Performance analysis shows that the new system will have an effective spatial resolution of up to 1 cm in the magnetic midplane via magnetic flux surface mapping.
- OSTI ID:
- 21266551
- Journal Information:
- Review of Scientific Instruments, Vol. 79, Issue 10; Other Information: DOI: 10.1063/1.2969078; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
- Country of Publication:
- United States
- Language:
- English
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