Beam Position on Target

• Check vertical beam position on target by centering X' (θ_tg) from the central sieve-slit hole.
• Horizontal target scan (LH2, dummy):

1. With the liquid hydrogen target, move beam from 'nominal' center by -5mm, -2.5 mm, 0 mm, 2.5 mm, 5 mm and take 200k events.
2. Scan beam to find edges of the dummy target.