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Updated: Jun 28, 2026

Characterization of Recombination Effects in a Liquid Ionization Chamber Used for the Dosimetry of a Radiosurgical Accelerator
Published on: May 9, 2014
[Impact on the PDD of MV X-ray for the glass mirror in linac]
Yu Chen1, Yong Yang, Jiu-Qing Wan
1Equipment Dept., Xinqiao Hospital, Third Military Medical University, Chongqing, 400037.
Objective:
To explore the effect on the iso-center and OAR and PDD of the MV class X-ray coming from the linac when we use the glass mirror to replace an imported one.
Method:
Data collected by using a film and 3D water phantom OAR and PDD measuring methods based on the different conditions. Comparison and analysis of the effect levels for different thickness and material mirrors are made.
Result:
The PDD max error of the 4 mm general glass mirror is 6%.When the 8MV X-ray 720 Gy irradiation is given, the light field appears a dual cross lines and has darker brightness. The PDD max error of the 1.5 mm quartz glass mirror is less than 1%. When it accepts the equal radiation dose, the light field iso-center and OAR and field brightness are agreed well with clinical demands.
Conclusion:
Our practice shows that the 4 mm general glass mirror can't suffer the MV class X-ray irradiation but the thin quartz glass mirror can. So the thin quartz glass mirror can be used for the linac.

