AIM The aim of this study is to quantify the influence of the photon energy spectrum of brachytherapy sources on task group No. 43 (TG-43) dosimetric parameters. BACKGROUND Different photon spectra are used for a specific radionuclide in Monte Carlo simulations of brachytherapy sources. MATERIALS AND METHODS MCNPX code was used to simulate 125I, 103Pd, 169Yb, and 192Ir brachytherapy sources...

Effects of disorder and exciton-phonon interactions are the major factors controlling photoinduced dynamics and energy-transfer processes in conjugated organic semiconductors, thus defining their electronic functionality. All-atom quantum-chemical simulations are potentially capable of describing such phenomena in complex "soft" organic structures, yet they are frequently computationally restri...

Purpose: To quantify the DNA damage induced in a clinical megavoltage photon beam at various depths in and out of the field. Methods and Materials: MCNPX was used to simulate 10x10 cm and 20x20 cm 10 MV photon beams from a clinical linear accelerator. Photon and electron spectra were collected in a water phantom at depths of 2.5, 12.5 and 22.5 cm on the central axis and at off-axis points out t...

Oneand two-photon fluorescence excitation spectra of the S1←S0 transitions of the all-trans isomers of 1,3,5,7-octatetraene, 1,3,5,7-nonatetraene, and 2,4,6,8-decatetraene have been obtained in free jet expansions. Comparison of the oneand two-photon spectra allows the unambiguous identification of electronic and vibronic origins and, for octatetraene and decatetraene, provides clear evidence f...

We describe models of nonthermal photon emission from a homogeneous distribution of relativistic electrons and protons. Contributions from the synchrotron, inverse Compton, nonthermal bremsstrahlung and neutral-pion decay processes are computed separately using a common parameterization of the underlying distribution of nonthermal particles. The models are intended for use in fitting spectra fr...

Optogalvanic (OG) spectra of argon in the visible to near-infrared spectral region between 735 and 850 nm were investigated using a Grimm-style glow-discharge tube, which has been widely used to obtain depth profiles of the elemental composition on various film-like samples. About 49 lines of one-photon and two-photon OG peaks were observed with a pulsed Ti:sapphire laser; these peaks were prec...