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Title: Fast photodiode arrays for high frequency fluctuation measurements of reconnecting flux ropes
An array of compact, high-bandwidth (>200 MHz) and low-cost optical photodiodes has been developed and implemented on the PHASe MApping (PHASMA) experiment. Using purpose-built electronics, an array of 16 photodetectors was constructed and used to monitor broadband (1–5 MHz) fluctuations in light intensity emitted by flux ropes undergoing electron-only magnetic reconnection. These measurements reveal a swath of oscillatory behavior, including wave propagation inward toward the diffusion region at approximately the local electron Alfvén speed. Custom 3D-printed collection optics and mounting hardware allow quick reconfiguration of the array for radial or axial measurements. The electronics design is flexible enough to be used with other current-sourcing transducers, such as avalanche photodiodes; silicon photomultipliers; and infrared, x-ray, and UV photodiodes. A noise-rejecting electrical layout allows for low-noise operation close to pulsed plasma discharges. A 16-channel, 64-pixel tomographic array was constructed and initial reconstructions are presented.  more » « less
Award ID(s):
1902111
PAR ID:
10612291
Author(s) / Creator(s):
; ; ;
Publisher / Repository:
Review of Scientific Instruments
Date Published:
Journal Name:
Review of Scientific Instruments
Volume:
95
Issue:
9
ISSN:
0034-6748
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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