Analysis Results for Activated Packard 21-634 PPO



Zelimir Djurcic and Andreas Piepke
University of Alabama
(Status 5/2/2001)
(Updated 5/15/2001)
(Final update 6/11/2001)


In this note we describe our analysis of the activated PPO sample (Packard 21-634) UA19, UA20 and UA21. After activation this sample has been removed from the irradiation vilas by means of acid digestion. No further separation of activities was done. The conversion of measured activities into chemical concentration assumes an extraction efficiency of 100%.
In the table below we list the activities in [Bq] determined for that sample. Shipping delay and sample mass are given as well. The errors quoted are statistical only. We estimate the systematic error to be ±10%. It is mainly caused by differences in the sample placement after sample changes. It can be seen e.g. in the 60Co and 65Zn data.

Activity [Bq]
Sample Mass [g] Delay [h] 24Na 42K 46Sc 51Cr 59Fe 60Co 65Zn 82Br 122Sb 124Sb 140La 198Au 233Pa 239Np
UA19-21 3.4954 54.9840 62230±90 806±266 1.37±0.02 36.4±0.26 3.24±0.03 22.1±0.04 23.23±0.08 822±1.2 933±2.2 26.45±0.05 4.4±0.43 14±0.2 0.16±0.06 -1.5±0.6
Empty vials UA 19-21 7.8304 54.9840 33800±72 38±91 5.5±3 102±0.6 4.18±0.06 17.7±0.04 6.2±0.06 961±5.2 75±3.3 2.65±0.03 0.26±3.9 18.6±4.1
Virgin vials UA 9-11 7.8803 60.0336 0.94±0.04 31±1 3.45±0.09 3.3±0.03 4.38±0.08 61.1±0.2



We use now the neutron flux as provided by MIT to determine the chemical concentrations of the elements listed above. A discussion of the neutron capture cross sections used for this analysis may be found on the web. The errors given below are the quadratic sum of the statistical and a 10% systematic error. The scaling of the neutron flux along the irradiation rabbit has not been taken into account here.


Concentration
Sample Na
[µg/g] 		K
[ng/g] 		Sc
[pg/g] 		Cr
[ng/g] 		Fe
[ng/g] 		Co
[ng/g] 		Zn
[ng/g] 		Br
[ng/g] 		Sb Sb La
[pg/g/] 		Au
[pg/g] 		Th
[pg/g] 		U
[pg/g]
UA19-21
acid extrct.		 1.8±0.2 302±104 14±1.4 6.2±0.6 176±18 1.5±0.2 70±7 7.1±0.7 21±3 4.6±0.5 6.1±2.2 -5.5±2.2
CIT
no extrct.		 1.2±0.2 19±15 <59 <0.65 950±700 <36 19±2 <20 <32 <450 <410
Large vials
UA Mar. 2001		 0.45±0.05 6.3±15 25±14 7.7±0.8 100±10 0.6±0.06 8.3±0.8 3.7±0.4 2.7±0.7
Large vials
CIT Jan. 2001		 1.1±0.1 31±15 12±2 310±40 0.65±0.08 21±2 3.2±0.3 81±9 30±23 <40
Large vials
CIT Mar. 2001		 0.37±0.05 18±0.3 <11 0.34±0.07 <160 10.5±4 1.2±0.1 7.0±0.9 95±11 <58 <33
This page is maintained by A. Piepke
Last update June 11, 2001