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High brilliance synchrotrons and FELs require high performing detector systems to realise their full potential. High dynamic range, low noise and high frame rate are all of great importance. In this paper we present first optical characterization results of the P2M CMOS sensor, designed for soft X-ray detection at such facilities. Previous work is summarised and an overview of the sensor is presented. Test results for the sensor’s column-parallel ADC and readout chain are presented, and first test results for the pixel acquired using the Photon Transfer Curve (PTC) method are shown. Finally, an outline of future work is provided.

Considerable interest has been manifested for the use of high-brilliance X-ray synchrotron sources and X-ray Free-Electron Lasers for the investigation of samples.

The High Efficiency Multi-mode Imager (HEMI) is a combined Compton and coded mask imager designed to detect and image gamma rays from ~30 keV up to a few MeV. It consists of 1-cm3-size coplanar-grid CdZnTe detectors with an energy resolution of ~2 % FWHM at 662 keV. We present the simulation and data analysis pipeline for HEMI as well as first results from measurements with an eight-detector test setup in Compton mode (spectra, angular resolution, and reconstructed images) and comparisons with simulations.

Cosima is the Geant4-based simulator of the medium-energy gamma-ray astronomy library MEGAlib. Within the MEGAlib framework, Cosima is designed to be a simple, fool-proof interface to Geant4 and to enable the simulation of most of the measurement scenarios encountered by X-ray and gamma-ray detectors in space and on Earth.

Hard X-ray and low-to-medium-energy gamma-ray telescopes may be exposed to many different types of background radiation ranging from cosmic rays to secondary particles from Earth’s atmosphere and charged particles trapped in radiation belts. Due to low source count rates in this energy regime, the background will dominate the source signal in many cases, in some up to a factor of 100. Therefore reliable Monte Carlo simulations of the background are extremely important to understand the recorded data and to predict the performance of future telescopes. We report on the status of the development and verification of a Geant4-based tool to simulate those background components, especially the resulting detector activation due to hadron interactions, as a successor to MGGPOD. Initial comparisons between simulations and background measurements of the TGRS detector are promising: Geant4 can reproduce the shape of the background to an accuracy better than 20%. In addition, many of the nuclear activation lines seen in the measurements are also present in the simulations — although there is still room for improvement especially with respect to the agreement of the line intensities.

The nuclear Compton telescope (NCT) is a balloon- borne soft gamma-ray (0.2 MeV-10 MeV) telescope designed to study astrophysical sources of nuclear line emission and polarization. A prototype instrument was successfully launched from Fort Sumner, New Mexico on June 1, 2005. The NCT prototype consisted of two 3D position sensitive high-purity germanium strip detectors (GeDs) fabricated with amorphous Ge contacts. We are currently working toward two balloon flights: another conventional balloon flight from Fort Sumner, New Mexico in September 2008, and a long-duration balloon flight (LDBF) from Alice Springs, Australia in December 2009. The NCT instrument is being upgraded to include all twelve planned GeDs. The electronics for all twelve detectors have been redesigned for smaller size, lower power consumption, and lower noise, and are now being fabricated and tested. Here we present our current progress in preparing for the flights.

The Nuclear Compton Telescope (NCT) is a balloon-borne soft gamma ray (0.2-10 MeV) telescope designed to study astrophysical sources of nuclear line emission and gamma ray polarization. A prototype instrument was successfully launched from Ft. Sumner, NM on June 1, 2005. The NCT prototype consists of two 3D position sensitive High-Purity-Germanium (HPGe) strip detectors fabricated with amorphous Ge contacts. The novel ultra-compact design and new technologies allow NCT to achieve high efficiencies with excellent spectral resolution and background reduction. We have completed our preliminary calibrations of both the energy and the 3D position of interactions for the prototype instrument. Determination of both the energy and the position is crucial for Compton imaging, and minimizing the errors in each improves the angular resolution. Because of the compact design of the detectors and the high spectral resolution of germanium, we expect the position uncertainties to dominate over energy uncertainties when determining the angular resolution. Detailed depth calibrations and a preliminary determination of angular resolution as a function of energy are described. We determine how measurement uncertainties and physical limitations (energy uncertainty, position uncertainty, Doppler broadening, and systematics) constrain the ultimate angular resolution.