373 / 1359
Detector
Appropiate for
Be careful
Ionization
chambers
❑
For x-ray depth dose
measurements
❑
Plane-parallel chamber for
build-up region
❑
Output factors large fields
❑
Output factors for small fields
(micro-chambers)
❑
Check polarity effect for both
photon and electron beams
❑
Always measure with the same
nominal V
❑
For micro-chambers the stem
signal can be an issue
❑
Correct by Sw,air for electron
depth dose measurements.
❑
Use small volume detectors for
scanning
❑
Effective point of measurement
❑
Check stability temperature
during measurements
Diodes
❑
Depth dose measurements
and profiles
❑
Shielded detector for x-rays
❑
Non-shielded for electron
beams
❑
Output factors
❑
Shielded detector
standard/large fields
❑
Non-shielded for small fields
❑
Energy dependence
❑
Sensitivity variation with
accumulated dose
❑
May present sensitivity variation
with dose rate
❑
Check stability temperature
during measurements