Energy

6 MV

6 FFF

15 MV

6 MeV

9 MeV

12 MeV

N

29

21

26

24

24

26

σ k 2

1.76 × 10−5

1.91 × 10−5

1.83 × 10−5

2.69 × 10−5

2.44 × 10−5

2.93 × 10−5

σ k

0.0042

0.0044

0.0043

0.0052

0.0049

0.0054

σ IROC 2

1.12 × 10−4

1.73 × 10−4

7.82 × 10−4

2.14 × 10−4

2.67 × 10−4

1.40 × 10−4

σ IROC

0.0106

0.0132

0.0088

0.0146

0.0163

0.0119

p-value

<0.01

<0.01

<0.01

<0.01

<0.01

<0.01