An integrated 6 MV linear accelerator model from electron gun to dose in a water tank

Abstract

An integrated simulation of an inline side-coupled 6 MV linac has been completed and benchmarked matching all electrical and dosimetric measurements to high accuracy. The results showed non-Gaussian spatial intensity and energy distributions for the linac modeled.

Performance of a clinical gridded electron gun in magnetic fields: Implications for MRI‐linac therapy

“…Previous studies have either tested models which are no longer used clinically 3 or have inferred the gun geometry based on measurements of emission current and high voltage. 2 Regarding the latter approach, it is worth noting that this is a degenerate problem, meaning that multiple geometries can produce the same emission current at a given high voltage. This is important as gun geometry directly affects sensitivity to magnetic fields-particularly for the in-line case.…”

“…[2][3][4] Low emittance indicates a more ordered beam, and in general lower emittance results in decreased loss through a beam transport line. However, there is no published data on how important emittance actually is in medical accelerators, and there are no published data regarding the measured emittance of medical electron guns.…”

“…Since MRI-linac radiotherapy requires that an electromagnetically sensitive electron accelerator functions within the magnetic fringe field of an MRI scanner, the emergence of MRI-linac radiotherapy has driven increased efforts in linear accelerator simulation amongst the medical physics research community. Operation of the electron gun in external magnetic fields is one of the most sensitive and studied aspects of integrated MRI-linac systems, [1][2][3][4][5] and is the focus of this paper. An electron gun is used to inject a steady stream of electrons at kilovoltage (kV) energies into an accelerating waveguide, where they are accelerated to megavoltage (MV) energies.…”

FEM design and simulation of a short, 10 MV, S‐band Linac with Monte Carlo dose simulations

“…2) instead of the third as in our previous work. 16 This was done to allow the ability to vary the beam energy in the future. The coupling port in the first full cavity will allow the fields in the first half-cavity and the fields in the remaining cavities (AC2-AC6 in Fig.…”

“…In our previous work 16,18 to emulate the Varian 600C, we had accomplished this by adjusting the nose cone length (L NC in Fig. 1) to increase or decrease the cavity capacitance in order to adjust the frequency.…”