Advancements in parallel and cluster computing have made many complex Monte Carlo simulations possible in the past several years. Unfortunately, cluster computers are large, expensive, and still not fast enough to make Monte Carlo useful for calculations requiring a near real time evaluation period. For Monte Carlo simulations, a small computational unit called a Field Programmable Gate Array (...

PURPOSE To determine the in-air azimuthal anisotropy and in-water dose distribution for the 1 cm length of a new elongated (103)Pd brachytherapy source through both experimental measurements and Monte Carlo (MC) simulations. Measured and MC-calculated dose distributions were used to determine the American Association of Physicists in Medicine Task Group No. 43 (TG-43) dosimetry parameters for t...

Computational models of the human body have gradually become crucial in the evaluation of doses absorbed by organs. However, individuals may differ considerably in terms of organ size and shape. In this study, the authors sought to determine the energy-dependent standard deviations due to lung size of the dose absorbed by the lung during external photon and neutron beam exposures. One hundred l...

Higher initial dose rate and simplifying HDR room treatment of 169Yb element among other brachytherapy sources has led to investigating its feasibility as high-dose-rate seed. In this work, Monte Carlo calculation was performed to obtain dosimetric parameters of 169Yb, Model M42 source at different radial distances according to AAPM TG-43U1 and HEBD Report about HDR sources in both air vacuum a...

A novel means of combined spectroscopic and radiographic zero-knowledge warhead verification has been developed and investigated using Monte Carlo simulations. This verification approach, henceforth called "epi-ZK," uses timestructured beams of epithermal neutrons to verify weapon isotopics and geometry without creating or transmitting meaningful information about the device design. This method...

The purpose of this study was to compare dose measurements using ion chamber and radiochromic film dosimetry for a 35-keV synchrotron beam useful for Auger electron therapy. A 1.3-GeV electron beam, transported through a 3-pole superconducting wiggler magnet, produced a polychromatic photon beam from which a 35-keV beam (3.3 mm Al HVL) was selected using a monochromator. A 2.8 cm x 2.5 cm field...

With the advent of inexpensive computing power over the past two decades, applications of Monte Carlo radiation transport techniques have proliferated dramatically. At Los Alamos, the Monte Carlo codes MCNP5 [1] and MCNPX [2] are used routinely on personal computer platforms for radiation shielding analysis and dosimetry calculations. These codes are attractive for such applications because of ...

This work describes preliminary test studies with a dual-headed SPECT system that utilizes a new generation of silicon double-sided strip detectors (DSSDs) (Figure 1) with a 1-mm bulk thickness and larger active area (60 × 60 mm) as compared to standard gamma-ray silicon detectors. Furthermore, major improvements in the ASIC design make this detector very suitable for low-energy imaging of smal...

Quality Control (QC) parameters for an X-ray tube depend strongly on the accurate assessment of the primary spectrum. In previous works, a methodology to assess primary spectrum using a Compton spectrometry technique has been analyzed. This methodology consists in the use of a Monte Carlo (MC) model, by means of the MCNP5 code, to reproduce the physical phenomena involving the interaction of ph...