**
FUNDAMENTAL DECAY EQUATION
**

1. The number of radioactive atoms remaining in a sample and time— the fundamental decay equation:

N
_{
t
}
= N
_{
0
}
e
^{
−λt
}
or A
_{
t
}
= A
_{
0
}
e
^{
−λt
}

2. Where N
_{
t
}
is the number of radioactive atoms at time t, A
_{
t
}
is the activity at time t, N
_{
0
}
is the initial number of radioactive atoms, A
_{
0
}
is the initial activity, e is the base of natural logarithm = 2.718..., λ is the decay constant = ln 2/T
_{
p
}
^{
1⁄2
}
= 0.693/T
_{
p
}
^{
1⁄2
}
, and t is the time. T
_{
p
}
^{
1⁄2
}
= 0.693/λ

1. Bushberg, J. T. (2012). The essential physics of medical imaging. Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins.
Find it at Amazon

2. Heggie, J. C., Liddell, N. A., & Maher, K. P. (1997). Applied imaging technology. Melbourne: St. Vincents Hospital.

Ⓒ A. Manickam 2018

+ Home