Description
Tong Chen (RefleXion Medical Inc.)
Liang Huo, Tong Li, Hao Tao, Zhen Feng, Liang Hu, Lin Zhou, Yongtao Liu (Chengdu Elekom Vacuum Electron Technology Co. Ltd)
Beam energy is an important parameter of linear accelerator. Compact linacs for medical or industrial applications are usually not equipped with beam monitors. The commonly used methods are “half value layer” (HVL) in industrial and “Percentage Depth Dose” (PDD) in medical to evaluate the beam energy of linac. However, these methods are not easily and accurately carried out, the HVL method needs big and heavy steel plates to prevent scattering x ray beams and PDD method need standard beam position and expensive 3d water tank to measure the beam energy. Most importantly, those methods cannot measure electron beam energy, but the photon distribution generated through Bremsstrahlung. This article introduced a method to measure and characterize the average electron beam energy when hitting the target by combining the external measurements and simulation beam profile results under different deflection magnetic field generated by steering coils. This method not only gives confidence in developing and operating the medical equipment but also reveals relation between beam energy and RF power settings. In addition, this paper provides energy and dose output variation across the RF pulse. This data provides guidance for proper setting of gun pulse width and timing.
| Paper status | Proceeding files received |
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