(1)] o [ θ 0123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990 [GeV] layer vertex - E E 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2 1 2 10 20 2 10 2 10 × 2 3 10 3 10 × 2 = 0 - exit barrel) B ( µ E ∆