

Q8
We are measuring a depth dose curve in a 15MV X-
ray beam. At point r
r
0
r
D
med
(r
0
) = D
det
(r
0
)·p (r
0
)· f
Q
(r
0
)·
D
med
(r) = D
det
(r)·p (r)· f
Q
(r)·
Sauer & Wilbert MP
34
, 2007, 1983-1988
1. A silicon diode will overestimate the dose to water
2. A silicon diode will underestimate the dose to water
3. An air ionisation chamber will underestimate dose to water
4. An air ionisation chamber will overestimate dose to water