Source fabrication and lifetime for Li+ ion beams extracted from alumino-silicate sources

作者：Roy Prabir K^*; Greenway Wayne G; Kwan Joe W

来源：Review of Scientific Instruments, 2012, 83(4): 043303.

DOI：10.1063/1.4704457

A space-charge-limited beam with current densities (J) exceeding 1 mA/cm(2) have been measured from lithium alumino-silicate ion sources at a temperature of similar to 1275 degrees C. At higher extraction voltages, the source appears to become emission limited with J >= 1.5 mA/cm(2), and J increases weakly with the applied voltage. A 6.35 mm diameter source with an alumino-silicate coating, <= 0.25 mm thick, has a measured lifetime of similar to 40 h at similar to 1275 degrees C, when pulsed at 0.05 Hz and with pulse length of similar to 6 mu s each. At this rate, the source lifetime was independent of the actual beam charge extracted due to the loss of neutral atoms at high temperature. The source lifetime increases with the amount of aluminosilicate coated on the emitting surface, and may also be further extended if the temperature is reduced between pulses.

• 出版日期2012-4