further note on the Orsay sims: threshold and "good events"

The PSSSD detectors have energy thresholds on both ends of each strip. The threshold is set to 500 keV right now. What that looks like in the code:

TflightResid = energy of ¹⁸O after dead layer of detector
RX0 = x-position of ¹⁸O along detector strip
...and the length of a detector is 50 mm, so the energy measured in either end is ERA or ELA:

ERA=TflightResid *(RX0+25)/50;
ELA=TflightResid-ERA;
if ((ELA >= hit_threshold)&&(ERA >= hit_threshold)) energyHitA=true;

...also: the Q-value distributions are made only from "good events": the ¹⁸O hits one of the "single" PSSSD detectors, and both alphas hit both a dE pad detector and the matching E PSSSD detector. There's a lot more events in the simulations that don't meet all those criteria.