Mainz, Universiẗat, Diss., 2002.

Th.--Sci. phys.--Clermont-Ferrand 2, 1977. N°: 245.

Th. 3e cycle--Phys. nucl. hautes énerg.--Grenoble 1, 1980. N°: 84.

University, Diss., 2002--Tübingen.

No description available.

In proton therapy systems with pencil-beam scanning, output of Halo effect is not necessarily included in Treatment Planning System (TPS). Halo effect (low-intensity tail) can significantly affect a patient’s dose distribution. The output of this dose depends on the field size being irradiated. Although much research has been made to investigate such relation to the field size, the number of reports on dose calculations including the halo effect is small. In this work we have investigated the Halo effect, including field size factor, target depth factor, and air gaps with a range shifter for a Varian ProBeam. Dose calculations created on the Eclipse Treatment Planning System (vs15.6 TPS) are compared with plane-parallel ionization chambers (PTW Octavius 1500) measurements using PCS and AcurosPT MC model in different isocenters: 5cm, 10cm, and 20cm. We find that in AcurosPT algorithm deviations range between -7.53% (for 2cm field in 25cm air gap with range shifter) up to +7.40% (for 20cm field in 15cm air gap with range shifter). Whereas, in PCS algorithm the deviations are -2.07% (for 20x20cm field in open conditions) to -6.29% (for 20x20cm field in 25cm air gap with range shifter). / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2021. / FAU Electronic Theses and Dissertations Collection

The backprojection-then-filtering algorithm was applied to proton CT data to reconstruct a map of proton stopping power relative to water (RSP) in air, water and bone. Backprojections were performed along three commonly used path estimates for the proton: straight line path, cubic spline path, and most likely path. The proton CT data was obtained through simulations using the GEANT4 simulation toolkit. Two elliptical phantoms were inspected, and an accuracy of 0.2% and 0.8% was obtained for the RSP in water and bone respectively in the region of interest, while the RSP of air was significantly underestimated.

The Zero Degree Calorimeter at STAR was used to calculate an asymmetry from small-angle scattering of neutral particles from proton-proton collisions at a center-of-mass energy of 500 GeV. An energy-centroid method was used to define hit positions of the neutral particles for each Shower Maximum Detector plane. An angular asymmetry analysis was done using these positions to measure both a left-right and a top-bottom asymmetry. The asymmetries were then used to calculate transversely-normal and sideways beam-polarization components for both of RHIC’s polarized-proton beams. The results of this analysis show that the Zero Degree Calorimeter Shower Maximum Detectors can be used as effective polarimeters at high beam energies, and can check the functionality of the spin rotators for longitudinally-polarized beams. The results of this analysis will be used in measurements that further the understanding of the source of a proton’s spin. / Department of Physics and Astronomy

No description available.

No description available.