Cs-doped Mo as surface converter for H−/D− generation in negative ion sources: First steps and proof of principle

• Main Authors: Schiesko, L., Hopf, C., Höschen, T., Meisl, G., Encke, O., Franzen, P., Heinemann, B., Fantz, U., Cartry, G., Achkasov, K.
• Format: Conference Proceeding
• Language: English
• Subjects: 07 ISOTOPES AND RADIATION SOURCES; ATOMS; CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; COMPARATIVE EVALUATIONS; Converters; DOPED MATERIALS; HYDROGEN; Hydrogen ions; HYDROGEN IONS 1 MINUS; Hydrogen plasma; ION SOURCES; MOLYBDENUM; MOLYBDENUM COMPOUNDS; Negative ions; PLASMA; PLASMA DENSITY; SURFACES; WORK FUNCTIONS; YIELDS
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/1.4916412

In a proof-of-principle study, molybdenum samples were implanted with a very small dose of Cs in order to test the properties of the compound as a surface converter for negative hydrogen ion production. First results on the properties of Cs doped Mo compounds show a reduction of the work function and a stable H− yield up to four hours in low density hydrogen plasma. The implanted Cs atoms were stable in the Mo lattice over one year for samples stored in vacuum and not exposed to the plasma. The surface H− generation mechanisms were identified and a comparison of the negative ion yield with pure Mo showed that the Cs doped Mo sample’s yield was much larger.