10 入cos0 od 2 sin2 0 8 △2 λ△0cos0 △d= 6 2sin0 2sin2 0 g0=0.01° 4- σ0=0.02° 2 o0=0.005° 0 0 10 20 30 40 50 60 70 80 90 Bragg angle,0(deg.)      2 2sin cos 2sin    d 