Na <- 6.0022*10^23 # アボガドロ数
TCs134 <- 2.0652*365.2425*24*60*60 # 半減期(秒)
# λ:崩壊定数, 放射能A=-dN/dt=λN, N=A/λ=A*T/log2, λ=log2/T
(Cs134g_Bq <- TCs134/(log(2)*Na)*134) # Cs134:1ベクレルのグラム数
(Cs134Bq_pg <- (1/Cs134g_Bq)/(1*10^12)) # Cs134:1pgのベクレル

TCs137 <- 30.16171*365.2425*24*60*60
(Cs137g_Bq <- TCs137/(log(2)*Na)*137) # Cs137:1ベクレルのグラム数
(Cs137Bq_pg <- (1/Cs137g_Bq)/(1*10^12)) # Cs137:1pgのベクレル


# 半減期を秒で計算
# λ=log2/T
λCs134 <- log(2)/TCs134
λCs137 <- log(2)/TCs137
N0 <- 1
Cesium134 <- function(s){
N0*exp(-λCs134*s)
}
Cesium137 <- function(s){
N0*exp(-λCs137*s)
}