Shielded ionisation discharge (SID) probe for spatiotemporal profiling of pulsed molecular beam

Area of Science:

• Plasma physics
• Atomic and molecular physics
• Beam technology

Background:

• Pulsed supersonic molecular beams are vital for applications like tokamak fueling and plasma diagnostics.
• Accurate absolute density measurement is essential for optimizing these beam sources.
• Measuring the density of transient, rarefied pulsed molecular beams presents significant challenges.

Purpose of the Study:

• To develop and demonstrate a novel probe for measuring the absolute number density of pulsed supersonic molecular beams.
• To characterize the spatiotemporal evolution of molecular beam density.

Main Methods:

• Development of a Shielded Ionization Discharge probe utilizing thermionic emission from a hot filament.
• Localized discharge within the molecular beam to measure ion current.
• Calibration and characterization of the probe's performance.

Main Results:

• Successful demonstration of the Shielded Ionization Discharge probe for density measurement.
• Characterization of spatial and temporal density profiles of a pulsed supersonic molecular beam.
• The probe effectively measures the transient nature of pulsed molecular beams.

Conclusions:

• The Shielded Ionization Discharge probe offers a reliable method for absolute density measurements of pulsed supersonic molecular beams.
• This technology can significantly aid in the optimization of beam sources for diverse scientific applications.
• The probe's ability to capture spatiotemporal evolution provides valuable insights into beam dynamics.