Distributed Read-out Imaging Device array for astronomical observations in UV/VIS

Contains fulltext : 74874.pdf (publisher's version ) (Open Access)STJ (Superconducting Tunneling Junctions) are being developed as spectro-photometers in wavelengths ranging from the NIR to X-rays. 10x12 arrays of STJs have already been successfully used as optical imaging spectrometers with the S-Cam 3, on the William Hershel Telescope on La Palma and on the Optical Ground Station on Tenerife. To overcome the limited field of view which can be achieved with single STJ arrays, DROIDS (Distributed Read Out Imaging Devices) are being developed which produce next to energy and timing also produce positional information with each detector element. These DROIDS consist of a superconducting absorber strip with proximized STJs on either end. The STJs are a Ta/Al/AlOx/Al/Ta 100/30/1/30/100nm sandwich of which the bottom electrode Ta layer is one with the 100nm thick absorber layer. The ratio of the two signals from the STJs provides information on the absorption position and the sum signal is a measure for the energy of the absorbed photon. In this thesis we present different important processes which are involved with the detection of optical photons using DROIDs. This includes the spatial and spectral resolution, confinement of the quasiparticles in the proximized STJs to enhance tunnelling and quasiparticle creation resulting from absorption of a photon in the proximized STJ. We have combined our findings in the development of a 2D theoretical model which describes the diffusion of quasiparticles and imperfect confinement via exchange of quasiparticles between the absorber and STJ. Finally we will present some of the first results obtained with an array of 60 360x33.5µm2 DROIDs in 3x20 format.RU Radboud Universiteit Nijmegen, 21 december 2009Promotor : Groot, P.J. Co-promotores : Verhoeve, P., Martin, D.142 p

Experimental and theoretical response of distributed read-out imaging devices with imperfect charge confinement

Contains fulltext : 83621.pdf (publisher's version ) (Open Access

Efficiency of quasiparticle creation in proximized superconducting photon detectors

Contains fulltext : 75666.pdf (publisher's version ) (Open Access)7 p

Position dependent spatial and spectral resolution measurement of distributed readout superconducting imaging detectors

Contains fulltext : 72071.pdf (publisher's version ) (Open Access)10 p

Imaging spectroscopy with Ta/Al DROIDs: Performance for different Al trapping layer thicknesses

Contains fulltext : 35795.pdf (publisher's version ) (Closed access)Electronic Article Available from Elsevier Science

Evaluation of a CdZnTe pixel array for X- and γ\gamma-ray spectroscopic imaging

Item does not contain fulltextElectronic Article Available from Elsevier Science

Superconducting tunnel junction detectors for soft x-ray astrophysics

Item does not contain fulltextThe requirement on energy resolution for detectors in future X-ray satelite missions such as XEUS (X-ray Evolving Universe Spectroscopy mission) is 80%. In addition, the requirements for field of view and angular resolution demand a detector array of typically 150x150 micron sized pixels in a 30x30 pixel format. DROIDs (Distributed Read Out Imaging Devices), consisting of a superconducting absorber strip with superconducting tunnel junctions (STJs) as read-out devices on either end, can fulfill these requirements. The amplitudes of the two signals from the STJs provide information on the absorption position and the energy of the incoming photon in the absorber. In this paper we present the development status of Ta/Al 1-D DROIDs, as well as the the short term development program that should result in a full size XEUS array.High Energy, Optical, and Infrared Detectors for Astronomy I

Imaging spectroscopy with Ta/Al DROIDs: Performance for different absorber lengths

Contains fulltext : 35796.pdf (publisher's version ) (Closed access)Electronic Article Available from Elsevier Science

Accurate time-resolved optical photospectroscopy with superconducting tunnel junction arrays

Item does not contain fulltextSuperconducting Tunnel Junctions (STJs) have been extensively investigated as photon detectors covering the range from near-infrared to X-ray energies. A 10�2 array of Tantalum/Aluminium junctions has been integrated into the S-Cam3 camera for ground based astronomy. With this camera, the European Space Agency has performed multiple astronomical observations of optical sources using the William Herschel 4.2m telescope at La Palma and the Agency's 1-m Optical Ground Station telescope at Tenerife. Compared to its predecessor, this new instrument features a 10"�2" field-of-view, an optimized IR rejection reducing baseline noise and increasing optical light throughput and ultra-stable operations. In this paper, we review the instrument's architecture and describe the system's performance and in particular the energy resolution and count-rate capabilities of the detector arrays. Finally, we shall present first astronomical images taken during the Optical Ground Station's 2005 and 2006 campaigns which demonstrate the system's timing, photometric and spectroscopic capabilities