First Application of a Digital Mirror Langmuir Probe for Real-Time Plasma Diagnosis

First Application of a Digital Mirror Langmuir Probe for Real-Time Plasma Diagnosis

First Application of a Digital Mirror Langmuir Probe for Real-Time Plasma Diagnosis 150 150 UKAEA Opendata
UKAEA-CCFE-PR(21)32

First Application of a Digital Mirror Langmuir Probe for Real-Time Plasma Diagnosis

For the first time, a digital Mirror Langmuir probe (MLP) has successfully sampled plasma temperature, ion saturation current, and floating potential together on a single probe tipin real time in a radiofrequency driven helicon linear plasma device. This is accomplished by feedback control of the bias sweep to ensure a good fit to IV characteristics with a high frequency,high power digital amplifier and fieldprogrammable gate array (FPGA) controller. Measurements taken by the MLP were validated by a low speed IV characteristic manually collected during static plasma conditions. Plasma fluctuations, induced by varying the axial magnetic field (f̃= 10 Hz), were also successfully monitored with the MLP. Further refinement of the digital MLP pushes it towards a turnkey system that minimizes the time to deployment and lessens the learning curve, positioning the digital MLP as a capable diagnostic for the study of low radiofrequency plasma physics. These demonstrations bolster confidence in fielding such digital MLP diagnostics in magnetic confinement experiments with high spatial and adequate temporal resolution such as edge plasma, scrapeoff layer, and divertor probes.

Collection:
Journals
Journal:
Review of Scientific Instruments
Publisher:
AIP (American Institute of Physics)
Published date:
06/10/2021