14.以小體積空腔度量劑量,當量測環境滿足Bragg-Gray空腔理論條件時,腔壁材質的劑量(Dw)
與空腔氣體劑量(Dg)的比值可以下列何式表示?(L/ρ:average restricted mass collisional
stopping power of electron, S/ρ:average mass stopping power)
(A)Dw = Dg × ( μen / ρ )w / ( μen / ρ )g
(B)Dw = Dg × ( L / ρ )w / ( L / ρ )g
(C)Dw = Dg × ( μ / ρ )w / ( μ / ρ )g
(D)Dw = Dg × ( S / ρ )w / ( S / ρ )g