Table 1 (abstract A22). Absolute sensitivity for point source, short phantom and long phantom in (a) air and (b) water

Number of rings

Point Source in 100 cm air phantom

20 cm air phantom

100 cm air phantom

4

2.03

1.81

0.815

8

6.06

5.82

2.97

12

10.14

10,01

5.98

16

13.62

13.38

9.37

20

16.27

16.22

12.63

Number of rings

Point Source in 100 cm water phantom

20 cm water phantom

100 cm water phantom

4

0.96

0.65

0.125

8

1.63

1.83

0.49

12

2.04

2.84

0.99

16

2.23

3.69

1.58

20

2.34

4.20

2.23