Elemental Analysis and Natural Radioactivity Levels of Clay by Gamma Ray Spectrometer and Instrumental Neutron Activation Analysis

Table 2

Clay composition and the average concentration of the elements calculated using INAA.

Element	Measured isotope	Half-life (T 1/2)	Energy: (keV)	Average concentration (ppm)	Statistical error (%)
Mg%	^27Mg	9.5 m	1014	5.3	6.74
Na%	^24Na	15 h	1369	26	0.26
K%	^42K	12.36 h	1525	6.9	6.87
Ti%	^51Ti	3.75 m	320	3.71	5.68
Mn%	^56Mn	2.6 h	846	29	1.31
Fe%	^59Fe	44.5 d	1099	0.84	2.60
Sc	^46Sc	38.8 d	889	842	0.24
Cr	^51Cr	27.7 d	320	274	2.40
Co	^60Co	5.3 y	1332	3.3	0.92
Zn	^65Zn	244 d	115	0.1	5.80
Ga	^72Ga	14.1 h	834	1.18	11.63
As	^76As	26.3 h	559	219	18.66
Rb	^86Rb	18.7 d	1077	5.9	5.38
Nb	^95Nb	34.98 d	766	1	2.91
Sn	^117Sn	13.6 d	158	15.11	20.6
Ba	^131Ba	11.8 d	496	0.14	9.90
La	^140La	40.3 h	1596	183	1.48
Ce	^141Ce	32.5 d	145	18.4	1.76
Eu	^152Eu	13.3 y	1408	16.5	4.31
Sm	^153Sm	46.3 h	103	106	0.89
Yb	^169Yb	32 d	198	31.3	5.34
Lu	^177Lu	161 d	208.4	77.4	4.69
Hf	^181Hf	42.4 d	428	9.8	2.60
Ta	^182Ta	114.43 d	1221	7.0	5.51
Th	^233Pa	27 d	312	12.6	3.08
U	^239NP	2.4 d	106	2.36	14.4