Se170063 Thin Window Analysis

In order to try to pin down the ratio of pure selenium to the selenium in the soil, try using a 2 channel window to find the signal. The error in the signal will be found by standard error propagation in mathematica. Since the max value is fixed, it does not appear in the stats box, but I have included it in the table.

	400 <t< 640 sec	1100 < t < 1360 sec	1875 < t < 2150	2650 < t < 2930 sec	3400 < t < 3690 sec	4120 < t < 4400 sec	4840 < t < 5130 sec
Thin Window
Original Window
Expanded Window
Maximum of Histogram	260980	241756	220348	191476	165549	139528	130930
Original Background	10560 +/- 51.58	10560 +/- 51.41	9496 +/- 48.9	8898 +/- 47.1	9418 +/- 48.2	7485 +/- 43	7032 +/- 31.1
Expanded Background	10750 +/- 42.42	10630 +/- 42.09	9674 +/- 40.2	9029 +/- 38.7	9248 +/- 39.1	7634 +/- 35.5	7161 +/- 34.2
Signal Background (Take Larger Error)	10560 +/- 51.58	10560 +/- 51.41	9496 +/- 48.9	8898 +/- 47.1	9418 +/- 48.2	7485 +/- 43	7161 +/- 34.2
Integrated Background	21120 +/- 103.16	21120 +/- 102.82	18992 +/- 97.8	17796 +/- 94.2	18836 +/- 96.4	14970 +/- 86	14322 +/- 68.4
Signal in Thin Window	466700 +/- 100640	444100 +/- 107283	412800 +/- 105315	356800 +/- 90173	304100 +/- 70249	258700 +/- 63183	233500 +/- 52406
Background Subtracted Signal	445580 +/- 100640	422980 +/- 107283	393808 +/- 105315	339004 +/- 90173.05	285264 +/- 70249.07	243730 +/- 63183.06	219178 +/- 52406.04
Time Correction Factor (Sec)	400	370	395	400	350	345	360
Corrected Counts	483015.53 +/- 109095.5248	455750 +/- 115595.0622	426463.63 +/- 114048.1804	367485.52 +/- 97748.96	306127.92 +/- 75387.02	261292.55 +/- 67735.87	235683.31 +/- 56352.50
.dat file entry	7.607165162 +/- 0.2258633895	7.469018062 +/- 0.2536369988	7.346511269 +/- 0.2676838585	7.179649592 +/- 0.2659940452	6.96187741 +/- 0.2462598642	6.838606337 +/- 0.2592338358	6.700363353 +/- 0.2391026331

Below is the table for the Se-Ash Mixture

	0 <t< 300 sec	730 < t < 1020 sec	1480 < t < 1775	2250 < t < 2550 sec	3050< t < 3300 sec	3775 < t < 4050 sec	4480 < t < 4770 sec
Thin Window
Original Window
Expanded Window
Maximum of Histogram	173289	155770	135740	124656	88582	80993	77781
Original Background	29440 +/- 84.93	20580 +/- 70.31	16420 +/- 62.52	14460 +/- 58.47	10950 +/- 50.65	10530 +/- 49.90	9809 +/- 48.2
Expanded Background	28960 +/- 69.12	20580 +/- 57.79	16500 +/- 51.60	14500 +/- 48.2	10630 +/- 41.29	10460 +/- 41.01	9814 +/- 39.7
Signal Background (Take Larger Error)	29440 +/- 84.93	20580 +/- 70.31	16420 +/- 62.52	14460 +/- 58.47	10950 +/- 50.65	10530 +/- 49.90	9809 +/- 48.2
Integrated Background	58880 +/- 169.86	41160 +/- 140.62	32840 +/- 131.04	28920 +/- 116.94	21900 +/- 101.3	21060 +/- 99.8	19618 +/- 96.4
Signal in Thin Window	342200 +/- 93025	300100 +/- 78768	267200 +/- 74554	238600 +/- 63777	170100 +/- 46436	153200 +/- 39780	147900 +/- 38766
Background Subtracted Signal	283320 +/- 93025.16	258940 +/- 78768.13	234360 +/- 74554.12	209680 +/- 63777.11	148200 +/- 46436.11	132140 +/- 39780.13	128282 +/- 37866.12
.dat file entry	6.850549805 +/- 0.3283395454	6.794470731 +/- 0.3041945238	6.677638317 +/- 0.3181179382	6.549555363 +/- 0.3041640118	6.384857074 +/- 0.3133340756	6.174846148 +/- 0.3010453307	6.092105322 +/- 0.2951787468

Below is a plot of the ratio of the activities where the pure selenium sample has been time corrected back to match the run time of the mixture.

Note that this does give the expected result that the ratio between the two samples is statistically the same as 0.5, which is the ratio of the masses. The only problem here is that the error is quite large, The average of the uncertainty divided by the mean is 39.6%.

Below are the half life plots for the Pure Selenium sample and the ash mixture

The slope of the mixture plot gives a half life of 63.48 +/- 26.85 minutes. This does overlap, but the error is extremely large.

The slope of the pure selenium sample plot gives a half life of 56.08 +/- 16.33 minutes. Again this does overlap, but the error is still quite large.

The ratio of the initial activities is 0.49 +/- 0.13. Now this does fall within 1 standard deviation of 0.5, which is the value we want.