The effect of a magnetic field on the plasma composition of a pulsed Au pla
sma stream in a high-vacuum ambient is described. The plasma was formed wit
h a pulsed vacuum-arc-plasma source, and the time-resolved plasma compositi
on was measured with time-of-flight charge-to-mass spectrometry. Plasma imp
urities due to ionization of nonmetallic species (H+, O+, and N+) were foun
d to be below the detection limit in the absence of a magnetic field. Howev
er, in the presence of a magnetic field (0.4 T), the contribution of ionize
d nonmetal species to the plasma composition was up to 0.22 atomic ratio. T
hese results are characteristic of plasma-based techniques where magnetic f
ields are employed in a high-vacuum ambient. In effect, the impurity incorp
oration during thin-film growth pertains to the present findings. (C) 2000
American Institute of Physics. [S0003-6951(00)00712-9].