Forward Modeling Using Experimental Response Functions for High-Resolution CZT Imaging Spectrometers

Large-volume 3D-position-sensitive CdZnTe is used in many applications. In many of these applications, it is useful to quickly predict what the spectral and image response will be to a particular source and environment. For instance, in scenario simulation or measurement planning, one would like to know what output can be expected. Some analysis methods may also benefit from having estimates of the spectrum and simple-back-projection image for many scenarios. Such a forward model is developed here. Instead of traditional method using Monte-Carlo or deterministic transport, or analytic functions, this forward model is accomplished using interpolations between over 2400 hours of characterization measurements. Details of the interpolation methods will be presented along with representative results comparing the forward model with measurements of new scenarios.