No abstract

The Gamma Detector Response and Analysis Software (GADRAS) applies a Detector Response Function (DRF) to compute the output of gamma-ray and neutron detectors when they are exposed to radiation sources. The DRF is fundamental to the ability to perform forward calculations (i.e., computation of the response of a detector to a known source), as well as the ability to analyze spectra to deduce the types and quantities of radioactive material to which the detectors are exposed. This document describes how gamma-ray spectra are computed and the significance of response function parameters that define characteristics of particular detectors.

A procedure for the design of low-loss continuous curvature waveguide bends, for use in integrated photonic circuits, is presented. The design employs the scalar finite element method and a technique for drawing waveguide bends based on their curvature. The finite difference beam propagation method is used to determine the power lost along the length of the waveguide structures. This new method allows the design of waveguide bends with lower loss than can be obtained by conventional methods.