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Unexpectedly large dose rate dependent output from a linear accelerator.

P C Cheng·H Kubo
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Abstract

During our routine calibration of a Varian Clinac-20 linear accelerator, the absorbed dose for a fixed monitor unit (mu) was found to decrease with increasing dose rate. Between dose rates of 100 and 500 mu/min, there was up to 20% difference in absorbed dose for a 20-MeV electron beam. The cause of this problem was a failure in the electronics circuit of an integrating board. This paper presents our analysis of the problem and suggests a possible means of isolating such a failure to warn technologists, physicists, and engineers.

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Biophysical PhenomenaBiophysicsHumansParticle AcceleratorsRadiometryRadiotherapy DosageRadiotherapy, High-EnergyJournal Article

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P C Cheng, H Kubo. Unexpectedly large dose rate dependent output from a linear accelerator.. https://doi.org/10.1118/1.596192

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