PURPOSE To calculate the output factor (OPF) of any irregularly shaped electron beam at extended SSD. METHODS Circular cutouts were prepared from 2.0 cm diameter to the maximum possible size for 15 × 15 applicator cone. In addition, two irregular cutouts were prepared. For each cutout, percentage depth dose (PDD) at the standard SSD and doses at different SSD values were measured using 6, 9, ...

Purpose: This study was to investigate the effect of irregularity in shape of field size of electron beam on the percentage depth dose and the output factor. Study the variety of the Percentage Depth Dose (PDD) and the output factors for rectangular and small field sizes when one of field dimensions less than the Practical Range (Rp) of the electron energy used. Compare the measured output fact...

In the present paper, we show that elliptical galaxies (Es) obey two laws. The first one accounts for the fact that Es are relaxed systems in a post violent-relaxation stage; they are quasi-equilibrium gravitational systems and therefore have a quasi-constant specific entropy. The second physical law is a scaling relation between potential energy and mass. Assuming that light traces mass, these...