What is Reference Source Method for Half Life Determination?
Half life determination: Part 3 Determination of t 1/2 ~ 10 ^9 years or more by Reference source method Reference source method ( t 1/2 ratio method) Parker, J. L. (1990) Half life of 147Sm was obtained by Kajan, Ivan et al (2021) using the radionuclide 232Th, whose half life was known earlier. Relative counting rates of both the radioisotope was obtained. Activity ratio of them was known. Using the t1/2 of 232Th as 1.41 x 10^10 years, 147Sm's half life was obtained as 1.06 (± 0.02) x 10^11 years. . A 0 and A are the activity of the radioisotope 1 or 2 at time t = 0 and t = t. t1/2 of radioisotope is known. From the slope of plot of ln A 2/ A 1 vs t , λ 2 can be obtained easily. From λ 2 , t1/2 of 2nd radioisotope can be obtained easily. Reference source method ( Parker, J. L. (1990) et al ). Advantage Simple Most suitable for gamma emitters Disadvantage Difficult to obtain data for pure beta emitters due to continious nature ...
