Gamma Spectrometry - Efficiency Calculation for K-40

Gamma Efficiency for K-40

Activity

Define activity, A = Number of spontaneous disintegrations in a source in one second.

Unit of activity, A = Bq (Becquerel)

Activity, A

N = Number of atom for K40

λ = Decay constant

t = Time

Specific Activity

Half-life

λ is a decay constant, therefore

How to calculate Activity and efficiency of K40 in KCl for Gamma Spectrometry

(eg. Standard KCl, 400g was used to calibrate the gamma spectrometry)

a) Calculate Mass of K in KCl

=

b) Calculate Mass K40 in 209.779 g K

=
=
= g

c) Calculate Number of atom K40

d) Calculate Decay constant, λ for K40

e) Calculate Activity K40 in KCl

f) Efficiency K40 for Gamma Spectrometry

(eg. Counting time = 43200 s, peak area = 140 000)

EDXRF - Calibration

Guideline for students

The most important task that need to be completed in sample measurement is calibration of the instrument. without the calibration, the quantitative analysis can't be done and to do that, we need to get the calibration graph and their equation. this is the manual technique for carried out the calibration of the instrument. below is a technical note of standard calibration of EDXRF.

to view full page [click here]

when do the calibration, student need to do some background study about EDXRF and literature review. Further literature review about the condition of the samples, energy line measure, measured line ( K, L, M), sample preparation and others will help student more understand.