The ROSATmission gave us the unique possibility to study the galactic interstellar medium by “shadowing” observations on arcmin angular resolution level. The high sensitivity of the ROSAT PSPC in combination with the large field of view allows the detailed study of individual clouds, while the ROSAT all-sky survey is the main source for studies of the large-scale intensity distribution of the d...

Among the secondary detection effects in gamma-ray spectroscopy with HPGe detectors that reduce the peak area and must be properly taken into account in accurate measurements, the less well known is counting loss by beta and gamma-ray sum coincidence. The fraction of lost counts was estimated assuming that a photon detection event can sum either with the coincident beta-ray or its bremsstrahlun...

Crystal growth and detector fabrication technologies have reached such a state of maturity that high-quality large-volume CeBr3 scintillators can now be produced with dimensions of 2′′×2′′ and well above. We present a study of CeBr3 samples of various dimensions and show that they have a number of advantages over equivalently sized LaBr3:5%Ce for gamma-ray spectroscopy applications requiring hi...

Image segmentation is an important stage in any image processing process. Regions of interest in the image are extracted from the image and are used to interpret the information in the image. This study investigates the image segmentation of X-ray images and aims at separating the bone from the rest of the X-ray. Basic edge detection techniques and Active Shape Models are the image segmentation...

Earth’s atmosphere is constantly being bombarded with cosmic rays. However, the origin and effect of this radiation is relatively unknown. We report on the results of a payload that was launched on the balloon sat EOSS flight 201 under the fall DemoSAT program for the COSGC. The payload was designed to measure these cosmic rays using an onboard geiger counter. These results are intended to be u...

The spectrometer SPI, one of the two main instruments of the INTEGRAL spacecraft, has strong capabilities in the field of GammaRay Burst (GRB) detections. In its 16 field of view (FoV) SPI is able to trigger and to localize GRBs with an accuracy for strong bursts better than 1. The expected GRB detection rate is about one per month.

A novel scintillating optical fiber is presented using a composite micro-structured quartz optical fiber. Scintillating materials are introduced into the multiple inclusions of the fiber. This creates a composite optical fiber having quartz as a cladding with an organic scintillating material core. X-ray detection using these fibers is compared to a collimated cadmium telluride (CdTe) detector ...

DETECTOR RESOLUTION Resolution is a measure of the width (full width half max) of a single energy peak at a specific energy, either expressed in absolute keV (as with Germanium Detectors), or as a percentage of the energy at that point (Sodium Iodide Detectors). Better (lower FWHM value) resolution enables the system to more clearly separate the peaks within a spectrum. Figure 1.2 shows two spe...

DETECTOR RESOLUTION Resolution is a measure of the width (full width half max) of a single energy peak at a specific energy, either expressed in absolute keV (as with Germanium Detectors), or as a percentage of the energy at that point (Sodium Iodide Detectors). Better (lower FWHM value) resolution enables the system to more clearly separate the peaks within a spectrum. Figure 1.2 shows two spe...

We describe a gamma-ray imaging camera (GIC) for active interrogation of explosives being developed by NASAIGSFC and NSWCICarderock. The GIC is based on the Three-dimensional Track Imager (3-DTI) technology developed at GSFC for gamma-ray astrophysics. The 3-DTI, a large volume time-projection chamber, provides accurate, -0.4 mm resolution, 3-D tracking of charged particles. The incident direct...