He mass histograms integrated over the time periods indicated in Table 1 for events 1, 3, 4, and 5. Also shown in red for events 1, 3, and 5 is the event 4 histogram scaled according to the values given in the legends. The distribution of counts in the mass region 2.5–3.5 in event 4 is consistent with spillover from the ⁴He peak evident in the mass region 3.5–4.5 and not indicative of the presence of ³He. In contrast, the other three events have an excess of counts corresponding to ³He (evident from the comparisons to the scaled event 4 histogram).