Dose 2016

Detector

Appropiate for

Be careful

For x-ray depth dose measurements

Check polarity effect for both photon and electron beams

Ionization chambers

Plane-parallel chamber for build- up region

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.

Output factors large fields

Output factors for small fields (micro-chambers)

Use small volume detectors for scanning

Effective point of measurement

Check stability temperature during measurements

Depth dose measurements and profiles

Energy dependence

Diodes

Sensitivity variation with accumulated dose May present sensitivity variation with dose rate

Shielded detector for x-rays

Non-shielded for electron beams

Output factors

Check stability temperature during measurements

Shielded detector standard/large fields

Non-shielded for small fields