Negative Ion Beam production and Transport via the LEBT of the HV injector prototype
- Mr. Oleg SOTNIKOV
- Mr. Oleg SOTNIKOV (Budker Institute of Nuclear Physics)
High-voltage negative-ion based injector is under development at Budker Institute of Nuclear Physics. Negative ion part of the injector is studied at separate test stand and consists of: 1) the long-pulse RF surface-plasma source, 2) low energy beam transport line (LEBT), 3) single aperture 0.5-1 MeV accelerating tube. Deflecting magnets and high speed cryopumps (10^5 l/s), that are installed in LEBT, purify the transported negative ion beam from the co-streaming ﬂuxes of electrons, hydrogen atoms and molecules, and cesium vapor. As a result, the loading on the accelerating tube by harmful co-streaming and secondary particles is considerably reduced. It will enable more stable operation of the negative ion beam accelerator. Paper presents experimental results on 1 A, 90 keV H- beam production and transport through the LEBT to the multisection calorimeter, installed at distance 3.5 m from the source. The parameters of the transported beam were measured at distance 1.6 m by the movable Faraday cup and at the LEBT exit - by beam calorimeter. The efficiency of beam transport vs various source and LEBT parameters will be presented and discussed.