Compact and multi-view solid state neutral particle analyzer arrays on National Spherical Torus Experiment-Upgrade

Liu, D.; Heidbrink, W.W.; Tritz, K.; Fredrickson, E.D.; Hao, G.Z.; Zhu, Y.B.

doi:10.11578/1367167

Title: Compact and multi-view solid state neutral particle analyzer arrays on National Spherical Torus Experiment-Upgrade

Abstract

A compact and multi-view Solid State Neutral Particle Analyzer (SSNPA) diagnostic based on silicon photodiode arrays has been successfully tested on the National Spherical Torus Experiment-Upgrade (NSTX-U). The SSNPA diagnostic provides spatially, temporally, and pitch-angle resolved measurements of fast-ion distribution by detecting fast neutral flux resulting from charge exchange (CX) reactions. The system consists of three 16-channel subsystems: t-SSNPA viewing the plasma mid-radius and neutral beam (NB) line #2 tangentially, r-SSNPA viewing the plasma core and NB line #1 radially and p-SSNPA with no intersection with any NB lines. Due to the setup geometry, the active CX signals of t-SSNPA and r-SSNPA are mainly sensitive to passing and trapped particles respectively. In addition, both t-SSNPA and r-SSNPA utilize three vertically stacked arrays with different filter thickness to obtain coarse energy information. The experimental data show that all channels are operational. The signal to noise ratio is typically larger than 10 and the main noise is x-ray induced signal. The active and passive CX signals are clearly observed on t-SSNPA and r-SSNPA during NB modulation. The SSNPA data also indicate significant losses of passing particles during sawteeth, while trapped particles are weakly affected. Fluctuations up to 120 kHz, have been observedmore »« less

Authors:

; Heidbrink, W.W.; Tritz, K.; Fredrickson, E.D.; Hao, G.Z.; Zhu, Y.B.

Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)

Publication Date:: Tue Nov 01 00:00:00 EDT 2016

DOE Contract Number:: AC02-09CH11466

Research Org.:: Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)

Sponsoring Org.:: USDOE Office of Science (SC), Fusion Energy Sciences (FES)

Subject:: Charge exchange neutral particle fast ion distribution Silicon photodiodes

Keywords:: Charge exchange neutral particle fast ion distribution Silicon photodiodes

OSTI Identifier:: 1367167

DOI:: https://doi.org/10.11578/1367167

Citation Formats


                    Liu, D., Heidbrink, W.W., Tritz, K., Fredrickson, E.D., Hao, G.Z., and Zhu, Y.B. Compact and multi-view solid state neutral particle analyzer arrays on National Spherical Torus Experiment-Upgrade.  United States: N. p., 2016. 
        Web.  doi:10.11578/1367167.

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                    Liu, D., Heidbrink, W.W., Tritz, K., Fredrickson, E.D., Hao, G.Z., & Zhu, Y.B. Compact and multi-view solid state neutral particle analyzer arrays on National Spherical Torus Experiment-Upgrade.  United States.  doi:https://doi.org/10.11578/1367167

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                    Liu, D., Heidbrink, W.W., Tritz, K., Fredrickson, E.D., Hao, G.Z., and Zhu, Y.B. 2016.  
"Compact and multi-view solid state neutral particle analyzer arrays on National Spherical Torus Experiment-Upgrade".  United States.  doi:https://doi.org/10.11578/1367167.  https://www.osti.gov/servlets/purl/1367167. Pub date:Tue Nov 01 00:00:00 EDT 2016

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@article{osti_1367167,

  title        = {Compact and multi-view solid state neutral particle analyzer arrays on National Spherical Torus Experiment-Upgrade},

  author       = {Liu, D. and Heidbrink, W.W. and Tritz, K. and Fredrickson, E.D. and Hao, G.Z. and Zhu, Y.B.},

  abstractNote = {A compact and multi-view Solid State Neutral Particle Analyzer (SSNPA) diagnostic based on silicon photodiode arrays has been successfully tested on the National Spherical Torus Experiment-Upgrade (NSTX-U). The SSNPA diagnostic provides spatially, temporally, and pitch-angle resolved measurements of fast-ion distribution by detecting fast neutral flux resulting from charge exchange (CX) reactions. The system consists of three 16-channel subsystems: t-SSNPA viewing the plasma mid-radius and neutral beam (NB) line #2 tangentially, r-SSNPA viewing the plasma core and NB line #1 radially and p-SSNPA with no intersection with any NB lines. Due to the setup geometry, the active CX signals of t-SSNPA and r-SSNPA are mainly sensitive to passing and trapped particles respectively. In addition, both t-SSNPA and r-SSNPA utilize three vertically stacked arrays with different filter thickness to obtain coarse energy information. The experimental data show that all channels are operational. The signal to noise ratio is typically larger than 10 and the main noise is x-ray induced signal. The active and passive CX signals are clearly observed on t-SSNPA and r-SSNPA during NB modulation. The SSNPA data also indicate significant losses of passing particles during sawteeth, while trapped particles are weakly affected. Fluctuations up to 120 kHz, have been observed on SSNPA, and they are strongly correlated with magnetohydrodynamics (MHD) instabilities.},

  doi          = {10.11578/1367167},

  journal      = {},

  number       = ,

  volume       = ,

  place        = {United States},

  year         = {Tue Nov 01 00:00:00 EDT 2016},

  month        = {Tue Nov 01 00:00:00 EDT 2016}

}

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