in this paper, polyacrylamide/chromium acetate gel polymer system was prepared as water shut-off system to control water production in one of the iranian oil reservoirs condition. effect of various parameters such as temperature (90 °c) and water formation from view point of salinity and divalent cations, was evaluated on the gelation kinetic and gel strength using bottle testing method. the re...

background: accurate small radiation field dosimetry is essential in modern radiotherapy techniques such as stereotactic radiosurgery (srs) and intensity modulated radiotherapy (imrt). precise measurement of dosimetric parameters such as beam profile, percentage depth doses and output factor of these beams are complicated due to the electron disequilibrium and the steep dose gradients. in the p...

introduction: multiple fields and presence of heterogeneities create complex dose distributions that need three dimensional dosimetry. in this work, we investigated mr-based magic gel dosimetry as a three-dimensional dosimetry technique to measure the delivered dose to bladder and rectum in prostate radiation therapy. materials and methods: a heterogeneous slab phantom including bones was made....

background: in this work investigation of the normoxic pagat polymer gel dosimeter such as sensitivity, the r2-dose response with post time and the percentage depth dose (pdd) of pagat polymer gel dosimeter have been undertaken. materials and methods: using mri, the formulation to give the maximum change in the transverse relaxation rate r2 was determined to be 4.5% n,n'-methylenbis- acryl...

Background: Some tissues in human body are radiobiologically different from water and these inhomogeneity must be considered in dose calculation in order to achieve an accurate dose delivery. Dose verification in complex radiation therapy techniques, such as intensity‐modulated radiation therapy (IMRT) calls for volumetric, tissue equivalent and energy independent dosimeter. The purpose of this...

Three-dimensional (3D) gel dosimetry has a unique role to play in safeguarding conformal radiotherapy treatments as the technique can cover the full treatment chain and provides the radiation oncologist with the integrated dose distribution in 3D. It can also be applied to benchmark new treatment strategies such as image guided and tracking radiotherapy techniques. A major obstacle that has hin...

introduction: the conventional methods of dosimetry are not capable of dosimetry in such a small volume of less than one cubic millimeter. although the polymer gel dosimetry method based on magnetic resonance imaging (mri) could achieve three dimensional dosimetry with high resolution, a spatial resolution evaluation based on gel dose modulation transfer function has not been investigated yet. ...

Background: The purpose of this study was to evaluate the dependency of MAGICA polymer gel dosimeter response (R2) on different electron energies as well as on different mean dose rate for a standard clinically used linear accelerator. Materials and Methods: The sensitivity of the dosimeter was represented by the slope of calibration curve in the linear region measured for each modalit...