Negative ions are used in several contexts, from medicine to particle accelerators. The symposia on Negative Ions, Beams and Sources are conducted biannually starting in 2008 and welcome contributions on any aspect of the production and use of negative ions in basic or applied research. Particular emphasis this year will be on the application to the neutral beam injectors for the ITER nuclear fusion experiment. The scope of this Special Topic is to collect contributions on the most recent results of experimental investigations as well as theoretical modelling, presented at the 2022 edition of the symposium.
Example topics of the conference:

• Fundamental processes and modelling
• H– and D– sources for fusion and accelerators
• Negative ion sources for industrial and medical applications
• Beam formation and transport
• Beam acceleration and neutralization
• Beam lines and facilities
• Applications