Tommy Knöös
Sjukhusfysiker
The influence of air humidity on an unsealed ionization chamber in a linear accelerator
Författare
Summary, in English
The safe and accurate delivery of the prescribed absorbed dose is the central function of the dose monitoring and beam stabilization system in a medical linear accelerator. The absorbed dose delivered to the patient during radiotherapy is often monitored by a transmission ionization chamber. Therefore it is of utmost importance that the chamber behaves correctly. We have noticed that the sensitivity of an unsealed chamber in a Philips SL linear accelerator changes significantly, especially during and after the summer season. The reason for this is probably a corrosion effect of the conductive plates in the chamber due to the increased relative humidity during hot periods. We have found that the responses of the different ion chamber plates change with variations in air humidity and that they do not return to their original values when the air humidity is returned to ambient conditions.
Avdelning/ar
- Medicinsk strålningsfysik, Lund
Publiceringsår
1996
Språk
Engelska
Sidor
2541-2548
Publikation/Tidskrift/Serie
Physics in Medicine and Biology
Volym
41
Issue
11
Dokumenttyp
Artikel i tidskrift
Förlag
IOP Publishing
Ämne
- Radiology, Nuclear Medicine and Medical Imaging
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 1361-6560