68
Total Output Ion Beam Current
It is possible to obtain a estimate of the total ion beam current (I
B
) by
integrating the beam current density over the half sphere in front of the
ion source, using the angular ion beam current density profiles similar to
FIGURE B.3 and”FIGURE B.4” on page 67. FIGURE B.5 and FIGU
RE B.6
show total output ion be
am currents for normal range of operation of
interest for most applications in argon and oxygen. Typically, the total
current of accelerated ions is about 20 to 30% of the anode-to-cathode
current used to sustain the ion source discharge.
FIGURE B.5 Total Ion Beam
Current vs. Anode Voltage
at R=30cm (Argon).
Total Beam Current for in Argon at R=30 cm
0
0.5
1
1.5
2
2.5
3
50 100 150 200 250 300 350
Anode Potential (V)
Total Integrated Beam Current (A)
1A
3A
5A
7.5A
10A
FIGURE B.6 Total Ion Beam
Current vs. Anode Voltage at
R=30cm (Oxygen).
Total Beam Current for in Oxygen at R=30 cm
0
0.5
1
1.5
2
2.5
3
3.5
50 100 150 200 250 300 350
Anode Potential (V)
Total Integrated Beam Current (A)
1A
3A
5A
7.5A
10A
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