The Gun Test Facility (GTF) was built to test high-brightness sources for the proposed Linac Coherent Light Source (LCLS) at SLAC. The longitudinal emittance exiting the gun has been determined by measuring the energy spectrum after the linac as a function of the linac phase. The phase-space parameters defining the beam pulse width, correlated energy spread, and slice energy spread at the linac...

The electron beam from the linear accelerator is of size ~ 2 mm, whereas the size of the electron beam profile required for actual treatment is usually larger than 2 2 cm up to 30 30 cm at the iso-center. Therefore, scattering foils were optimized and simulated using FLUKA code. The primar scattering foil as kept niform thickness y w u , whereas the secondary foil was of Gaussian shape with var...

This paper presents dose calculation in proton therapy using Monte Carlo method and comparison with experimental data obtained at TOHOKU University’s cyclotron and isotope center in Japan. In this way, two Monte Carlo codes, FLUKA and MCNPX, has been employed to calculate percentage depth dose, lateral dose profiles, isodose curves and secondary particles production for proton pencil and broad ...

PURPOSE Linac parameters potentially influencing the delivery quality of IMRT and VMAT plans are investigated with respect to threshold ranges, consequently to be considered in a linac based quality assurance procedure. Three commercially available 2D arrays are used to further investigate the influence of the measurement device. METHODS Using three commercially available 2D arrays (Mx: Matri...

BACKGROUND The modalities for performing stereotactic radiotherapy (SRT) on the brain include the cone-based linear accelerator (linac), the flattening filter-free (FFF) volumetric modulated arc therapy (VMAT) linac, and tomotherapy. In this study, the cone-based linac, FFF-VMAT linac, and tomotherapy modalities were evaluated by measuring the differences in doses delivered during brain SRT and...

The authors report the first magnetic resonance (MR) images produced by their prototype MR system integrated with a radiation therapy source. The prototype consists of a 6 MV linac mounted onto the open end of a biplanar 0.2 T permanent MR system which has 27.9 cm pole-to-pole opening with flat gradients (40 mT/m) running under a TMX NRC console. The distance from the magnet isocenter to the li...

Two bunching schemes are considered in the frame of the CPS Linac, one with a single buncher, the other with a double-drift harmonic buncher. The matching of the beam to the Linac acceptance in six phase-space dimensions is achieved by computer programs in an iterative way: zero current solutions are found first, and then the intensity is progressively raised until 200 mA are trapped into the L...

Introduction: This study aimed to measure the neutron contamination of flattening filter (FF) and flattening filter-free (FFF) 10-MV photon beams delivered by the Elekta InfinityTM accelerator. Material and Methods: The photoneutron spectrum produced by the Linac head was evaluated using a Monte Carlo (MC) simulation. The geometry ...

Background: During intensity modulated radiation therapy (IMRT) technique, theoretically, presence of flattening filter (FF) across the beamline of clinical linear accelerator (linac) is not essential to obtain uniform lateral profiles due to intensity modulation of photon beams by multileaf collimators (MLCs). The aim of this study was to investigate the dosimetrical properties of 18 MV photon...

Introduction: In clinical electron beams, most of bremsstrahlung radiation is produced by various linac head structures. This bremsstrahlung radiation dose is influenced by the geometry and construction of every component of the linac treatment head structures. Thus, it can be expected that the amount of the contaminated photon dose due to bremsstrahlung radiation varies among different linacs,...