arXiv subjects

A. Orthen

Publications and source records attributed to A. Orthen.

3 recordsLinked to original sources

arXiv2003

On image reconstruction with the two-dimensional interpolating resistive readout structure of the Virtual-Pixel detector

The two-dimensional interpolating readout concept of the Virtual-Pixel detector (ViP detector) goes along with an enormous reduction of electronic channels compared to pure pixel devices. However, the special concept of the readout structure demands for adequate position reconstruction methods. Theoretical considerations reflecting the choice and the combination of linear algorithms with emphasis on correct position reconstruction and spatial resolution are presented. A subsequent two-dimensional coordinate transformation further improves the image response of the system. Measured images show how far the theoretical predictions of the simulations can be verified and to what extent they can be used to improve the position reconstruction.

physics.ins-det↗

arXiv2003

Gas gain and signal length measurements with a triple-GEM at different pressures of Ar-, Kr- and Xe-based gas mixtures

We investigate the gas gain behaviour of a triple-GEM configuration in gas mixtures of argon, krypton and xenon with ten and thirty percent of carbon dioxide at pressures between 1 and 3 bar. Since the signal widths affect the dead time behaviour of the detector we present signal length measurements to evaluate the use of the triple-GEM in time-resolved X-ray imaging.

physics.ins-det↗

arXiv2003

Investigation of the performance of an optimised MicroCAT, a GEM and their combination by simulations and current measurements

A MicroCAT (Micro Compteur A Trous) structure which is used for avalanche charge multiplication in gas filled radiation detectors has been optimised with respect to maximum electron transparency and minimum ion feedback. We report on the charge transfer behaviour and the achievable gas gain of this device. A three-dimensional electron and ion transfer simulation is compared to results derived from electric current measurements. Similarly, we present studies of the charge transfer behaviour of a GEM (Gas Electron Multiplier) by current measurements and simulations. Finally, we investigate the combination of the MicroCAT and the GEM by measurements with respect to the performance at different voltage settings, gas mixtures and gas pressures.

physics.ins-det↗