Multiaperture negative ion source

Negative ion production in the RF multiaperture surface-plasma source

“…1a. The main features of the source, whose detailed description was given elsewhere [2], follow the traditional design of a large-area radio frequency (RF) surfaceplasma source of negative ions [4,5]. The plasma, which is produced by an RF driver, flows to the expansion chamber and bombards the plasma grid (PG in Fig.…”

“…The system, based on the metallic cesium was also prepared [2]. Each oven in this system is equipped by two valves -by the pneumatic one to control the cesium flux and by the manual one -to detach the oven for reload in the glove box without cesium exposure to air.…”

“…Multiaperture, multi-electrode ion optical system (IOS) is used for negative ion beam extraction and acceleration. Several novel features were introduced in the BINP source [2]: 1) IOS grids are kept hot with thermal fluid circulating through channels machined in the electrodes, 2) the primary deposition of cesium is done directly at PG, 3) cesium is released from safe cesium chromate pellets loaded in the external oven.…”

“…The supporting flanges of IOS electrodes are water-cooled and sealed on the ceramic rings with the diameter of 520 mm. The axial and radial slots are cut in the supporting flanges to compensate for thermal expansion during the grids heating [2]. In the one-aperture extraction experiments, the central aperture of PG was opened, while the other 24 were closed with molybdenum plugs (Fig.…”

“…The negative ion source of the injector will deliver 120 keV Hbeam to the accelerator. A test stand for studying H-beam production and transport, and a prototype ion source designed to operate at the beam current of 1.5 A, the beam energy of 120 kV and the pulse duration up to 100 sec [2] have been manufactured. The first experiments on H-beam production were carried out.…”