SPIDER on-line data visualization tool

SPIDER (Source for Production of Ion of Deuterium Extracted from Radio Frequency plasma), has been operating in Padova since May 2018, with the aim to test and develop the ITER-scale radio-frequency negative ion source, to study the beam characteristics and to verify the source operation. The source produces more than 500 gigabyte per operational day. Extracting as much information as possible from a set of selected signals (plasma light, voltages and currents of power supplies, cameras, tomography, beam emission spectroscopy, caesium oven parameters and others) during an experimental day allows a more efficient use of the largest neutral beam operating source. The simultaneous visualization of signals, related to pre-defined times of interest arrays, monitors the state of the beam and source features from quite different points of view. However, the time evolution of signals of interest often does not represent the expected format for data analysis. The experimental pulse can be divided in phases called 'blips', which correspond to a given experimental configuration typically lasting 40 s. Blips are separated by time periods, required for changing the experiment settings to different configurations. Some punctual information is required for visualization, while derived information is then stored in a relational database for subsequent analysis. The derivation of punctual values was performed offline, with the disadvantage of not being able to derive results of interest during the experiment itself. The new tool derives blip-related information during the pulse, as soon as required data have been stored in the pulse file. The availability of such tool represents a big improvement in the exploitation of the scientific results of SPIDER that can be used in this way during the experimental session itself. Furthermore new features are being developed regarding the addition of other signals including secondary ones and the access to the database from multiple platforms.