Fig. 10

Mass spectrum of m/z = 4 from diamond-like carbon substrate. The matrix ion of ¹²C³⁺ and residual gas in the vacuum of ⁴He⁺ appeared (orange color line). Ion gates of LIMAS deflect ²C³⁺ ions from the multi-turn trajectory to reduce the intensity without affecting the ⁴He⁺ intensity (gray color line)