The time cuts for the yield measurements have been chosen to maximize the fusion signal of interest, while avoiding the background. For example, the US and DS fusions, when they coexist, can largely be separated by appropriate time cuts, since most US fusion takes place nearly promptly after the muon stop and disappears with typical time constant of ns (depending on the tritium concentration), while DS events occurs after time-of-flight across the drift distance, typically of order s. The standard time cuts of s, and s were used for the USY and TOFY measurements, respectively, while the MODY time cuts were slightly varied to maximize the signal-to-background ratio (e.g., with a thin US moderator, the energy is rather high, hence the time-of-flight short, which could overlap with US fusion). Table 8.3 summarizes the main conditions for the yield measurements.
Together with the partial yields for given time cuts, we give the total yield with the acceptance for the time cut estimated by SMC simulations. These corrections are typically 10% or less. The comparisons with Monte Carlo calculation results, which will be discussed later, will be done using the same time cuts for both the data and MC, hence the time cut efficiencies will cancel in those analyses (assuming the time distribution is predicted correctly by the MC).
The effects of the energy cuts on the yield were carefully studied by using different cuts, as well as estimating the efficiency using a dedicated Monte Carlo. These and other corrections will be discussed later.