Lost Alpha Faraday Cup Foil Noise Characterization During JET Plasma Post-Processing Analysis

Lost Alpha Faraday Cup Foil Noise Characterization During JET Plasma Post-Processing Analysis

Lost Alpha Faraday Cup Foil Noise Characterization During JET Plasma Post-Processing Analysis 150 150 Mathew
UKAEA-CCFE-PR(22)22

Lost Alpha Faraday Cup Foil Noise Characterization During JET Plasma Post-Processing Analysis

Capacitive plasma pickup is a well-known and difficult problem for plasma-facing edge diagnostics. Ths problem must be addressed to ensure an accurate and robust interpretation of the real signal measurements versus noise. JET’s Faraday cup fast ion loss detector array is particularly prone to this issue and can be used as a testbed to prototype solutions. The separation and distinction between warranted fast ion signal and anomalous plasma noise has traditionally been solved with hardware modifications, but a more versatile post-processing approach is of great interest. This work presents post-processing techniques to characterize the signal noise. While hardware changes and advancements may be limited, the combination with post- processing procedures allows for more rapid and robust analysis of measurements. The characterization of plasma pickup noise is examined for alpha losses in a discharge from JET’s tritium campaign. In addition to highlighting the post-processing methodology, the spatial sensitivity of the detector array is also examined which presents significant advantages for the physical interpretation of fast ion losses.

Collection:
Journals
Journal:
Review of Scientific Instruments
Publisher:
AIP (American Institute of Physics)