Imaging suprathermal x-rays from a laboratory plasma jet using PIN-diode-based and scintillator-based 1D...

Area of Science:

• Plasma Physics
• X-ray Imaging Technology

Background:

• Magnetohydrodynamic (MHD) instabilities in plasma jets produce transient, low-intensity, suprathermal x-rays.
• Understanding the dynamics and source localization of these x-rays is crucial for plasma disruption research.

Purpose of the Study:

• To develop and characterize novel 1D x-ray cameras for time-resolved imaging of plasma instabilities.
• To investigate the spatial and temporal characteristics of suprathermal x-rays emitted during plasma jet disruptions.

Main Methods:

• Development of PIN-diode-based and scintillator-based 1D x-ray cameras with microsecond to submicrosecond time resolution.
• Utilized pinhole and coded aperture imaging techniques outside a vacuum chamber.
• Acquired >50 time-resolved frames with a time resolution of ≤1 μs.

Main Results:

• Achieved high detection efficiency across a broad x-ray band with a wide field of view.
• Localized x-ray sources to within centimeters of an inner disk electrode or near a translatable metal frame (30-40 cm away).
• Coded apertures enhanced signal collection but introduced artifacts compared to pinhole imaging.

Conclusions:

• The developed 1D x-ray cameras are effective for time-resolved imaging of transient x-ray emissions from plasma instabilities.
• The imaging results provide insights into the spatial dynamics of MHD disruptions in plasma jets.
• Both pinhole and coded aperture methods offer complementary information for x-ray source characterization.