Background gas density and beam losses in NIO1 beam source

Area of Science:

• Plasma physics
• Ion source technology
• Vacuum systems

Background:

• Negative Ion Optimization 1 (NIO1) is an ion source for H- beam studies up to 60 keV.
• Ion sources require continuous gas injection and high vacuum for stable operation.
• Understanding gas dynamics is crucial for optimizing ion source performance.

Purpose of the Study:

• To investigate the three-dimensional gas flow within the NIO1 ion source.
• To analyze the influence of gas temperature and particle mass on gas density profiles.
• To compare simulation results with experimental pressure measurements.

Main Methods:

• Utilized the Avocado code for molecular flow regime simulations.
• Modeled gas flow considering effective source temperature and wall collision effects.
• Performed three-dimensional computational fluid dynamics analysis.

Main Results:

• Detailed gas density profiles along the accelerator were calculated.
• The impact of gas temperature accommodation and particle mass was quantified.
• Simulated pressures were compared against experimental data from NIO1.

Conclusions:

• The study provides a validated model for gas flow in the NIO1 ion source.
• Findings contribute to the understanding of gas dynamics in negative ion sources.
• This research aids in optimizing the design and operation of particle accelerators.