Abstract
A prototype of an infrared imaging bolometer (IRVB) was successfully tested on the Alcator C-Mod tokamak at the end of its 2016 campaign. The IRVB method interprets the power radiated from the plasma by measuring the temperature rise of a thin, ∼2 μm, Pt absorber that is placed in the torus vacuum and exposed, using a pinhole camera, to the full-spectrum of plasma’s photon emission. The IRVB installed on C-Mod viewed the poloidal cross section of the core plasma and observed Ohmic and ion cyclotron range of frequency (ICRF)-heated plasmas. Analysis of total radiated power and on-axis emissivity from IRVB is summarized, and quantitative comparisons made to data from both resistive bolometers and AXUV diodes. IRVB results are clearly within a factor of two, but additional effort is needed for it to be used to fully support power exhaust research. The IRVB is shown to be immune to electromagnetic interference from ICRF which strongly impacts C-Mod’s resistive bolometers. Results of the bench-top calibration are summarized, including a novel temperature calibration method useful for IRVBs.
Original language | English |
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Article number | 103507 |
Journal | Review of Scientific Instruments |
Volume | 89 |
Issue number | 10 |
DOIs | |
State | Published - Oct 1 2018 |
Funding
This work is supported in part by US Department of Energy Award Nos. DE-AC05-00OR22725 and DESC0014264, using Alcator C-Mod, a DOE Office of Science User Facility. The authors would like to thank the diligent work of R. Rosati at MIT-PSFC to quickly install and remove the IRVB on Alcator C-Mod, enabling these results possible.