The feasibility of detecting the photon-photon interaction using Fabry-Perot type laser interferometers developed for gravity wave detection is demonstrated. An “external” laser beam, serving as a refractive medium, is alternatively fed into the cavities of the interferometer and made to collide with the “internal” beams thereby inducing a measurable phase difference between them. [hep-ph/93082...

Despite the very small electron beam emittance in thirdgeneration light sources, the horizontal size of the emitted x-ray beam is still determined mainly by the electron beam divergence. Providing a converging electron beam in an undulator straight section can significantly decrease the spot size of the downstream x-rays, which leads to an increase in the photon flux density on the user sample....

Background: Gold nanoparticles are emerging as promising agents for cancer therapy and are being investigated as drug carriers, photothermal agents, contrast agents and radiosensitisers.Objective: The aim of this study is to understand characteristics of secondary electrons generated from interaction of gold nanoparticles GNPs with x-rays as a function of nanoparticle size and beam energy and ...

introduction: esophageal cancer is one of the most frequently occurring cancers in iran and having a  high  incidence  rate  among  other  countries.  radiotherapy  is  one  of  the  three  methods  (surgery,  radiotherapy and chemotherapy) for radical or palliative treatment of esophageal cancer. in this method  of treatment, the organs such as heart and spinal cord are regarded as organs at r...

This protocol describes the fabrication and characterization of nanostructures using a novel nanolithographic technique called Patterning via Optical Saturable Transitions (POST). In this technique the chemical properties of organic photochromic molecules that undergo single-photon reactions are exploited, enabling rapid top-down nanopatterning over large areas at low light intensities, thereby...

The beam size at the low emittance configuration of the Photon Factory was measured by the use of the SR interferometer. The spatial coherence of the visible SR beam was measured for both of the vertical and horizontal directions with the wavelengths at 500nm and 633nm. From the measured spatial coherence of the SR beam, the beam size measurements of 87.3μm in the vertical and 261.2 μm in the h...

In external beam radiation therapy (EBRT), the quality assurance (QA) of the radiation beam is crucial to the accurate delivery of the prescribed dose to the patient. One of the dosimetric parameters that require monitoring is the beam output, specified as the dose rate on the central axis under reference conditions. The aim of this project was to validate dose rate calibration of megavoltage p...

A filtered backprojection reconstruction algorithm was developed for cardiac single photon emission computed tomography with cone-beam geometry. The algorithm reconstructs cone-beam projections collected from ;short scan' acquisitions of a detector traversing a noncircular planar orbit. Since the algorithm does not correct for photon attenuation, it is designed to reconstruct data collected ove...