We present Simulated Annealing fiber-to-target allocation simulations for theproposed DESI and 4MOST massively multiplexed spectroscopic surveys, and forboth Poisson and realistically clustered mock target samples. We simulate bothEchidna and theta-phi actuator designs, including the restrictions caused bythe physical actuator characteristics during repositioning. For DESI, with theta-phi actuators, used in 5 passes over the sky for a mockELG/LRG/QSO sample, with matched fiber and target densities, a total targetallocation yield of 89.3% was achieved, but only 83.7% for the high-priorityLy-alpha QSOs. If Echidna actuators are used with the same pitch and number ofpasses, the yield increases by 5.7% and 16% respectively. Echidna also allows afactor-of-two increase in the number of close Ly-alpha QSO pairs that can beobserved. Echidna spine tilt causes a variable loss of throughput, with average lossbeing the same as the loss at the rms tilt. With a natural tilt minimizationscheme, we find an rms tilt always close to 0.58 x maximum. There is anadditional but much smaller defocus loss, equivalent to an average defocus of30microns. These tilt losses offset the gains in yield for Echidna, but becausethe survey strategy is driven by the higher priority targets, a clear surveyspeed advantage remains. For 4MOST, high and low latitude sample mock catalogs were supplied by the4MOST team, and allocations were carried out with the proposed Echidna-basedpositioner geometry. At high latitudes, the resulting target completeness was85.3% for LR targets and 78.9% for HR targets. At low latitude, the targetcompleteness was 93.9% for LR targets and 71.2% for HR targets.
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