STOF data acquired for the range of 60−84 E/q steps during days 206−211 in 2003. The panel shows the measured energy, E_SSD vs. TOF, while its inset shows the same data mapped to m-m/q space. Alpha particles are surrounded by a red square in the inset. The corresponding E_SSD-TOF measurements are surrounded by a mapped closed red curve that corresponds to the red rectangle in m-m/q space. The accidental coincidence events (or instrumental background) are uniformly distributed throughout the entire TOF region and fall randomly within the real ion zone, e.g., He⁺⁺. The large dashed magenta rectangle in the high-TOF region is used to estimate the background level of our measurements.