Fred Berendse - Academia.edu (original) (raw)
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Papers by Fred Berendse
High sensitivity hard X-ray data by means of focusing optics is crucially important to investigat... more High sensitivity hard X-ray data by means of focusing optics is crucially important to investigate active galaxies and cluster of galaxies. We have developed focusing telescopes with platinum-carbon multilayer coatings. The energy band is broadened by multilayers with graded periodic length, so called `Supermirrors'. We were successful to obtain hard X- ray images in the energy band from 25 to 40 keV with a demonstration model of telescope with 20 mirror shells of supermirrors. The flight model of supermirror telescope is now in production for balloon flight in the summer of 2000. The current status of the balloon mission and future application of supermirror technology is discussed.
The ability of periodic and aperiodic multilayer structures to diffract x-rays at grazing angles ... more The ability of periodic and aperiodic multilayer structures to diffract x-rays at grazing angles has long been understood, and has been successfully exploited in the x-ray region, primarily on flat substrates. We have recently begun producing Pt/C multilayer coated thin foil mirrors for the InFOC(mu) S balloon mission. The mirrors are made by depositing the multilayer on glass mandrels and transferring the multilayer to the thin foil substrates using a replication process similar to that used for production of the recently lost ASTRO-E mirrors. Both periodic and broadband versions have been successfully replicated onto thin foils and characterized by grazing incidence x-ray scattering. Initial comparisons between mirrors deposited on flat float glass substrates and mirrors replicated onto thin foils indicate that the reflection properties of the multilayer are not damaged by the transfer from mandrel to foil. We describe the production and characterization facilities that have been developed in our lab, and the performance of our multilayer mirrors, with particular emphasis on the characterization of interfaces in the Pt/C system.
The CZT detector on the Infocus hard X-ray telescope is a pixellated solid-state device capable o... more The CZT detector on the Infocus hard X-ray telescope is a pixellated solid-state device capable of imaging spectroscopy by measuring the position and energy of each incoming photon. The detector sits at the focal point of an 8m focal length multilayered grazing incidence X-ray mirror which has significant effective area between 20--40 keV. The detector has an energy resolution of 4.0keV at 32keV, and the Infocus telescope has an angular resolution of 2.2 arcminute and a field of view of about 10 arcminutes. Infocus flew on a balloon mission in July 2001 and observed Cygnus X-1. We present results from laboratory testing of the detector to measure the uniformity of response across the detector, to determine the spectral resolution, and to perform a simple noise decomposition. We also present a hard X-ray spectrum and image of Cygnus X-1, and measurements of the hard X-ray CZT background obtained with the SWIN detector on Infocus.
Applied Optics, 2003
The International Focusing Optics Collaboration for Crab Sensitivity ͑InFOCS͒ balloonborne hard x... more The International Focusing Optics Collaboration for Crab Sensitivity ͑InFOCS͒ balloonborne hard x-ray telescope incorporates graded Pt͞C multilayers replicated onto segmented Al foils to obtain the significant effective area at energies previously inaccessible to x-ray optics. Reflectivity measurements of individual foils demonstrate our capability to produce a mass quantity of multilayered foils with a rms roughness of 0.5 nm. The effective area of the completed mirror is 78 and 22 cm 2 at 20 and 40 keV, respectively. The measured half-power diameter is 2.0 Ϯ 0.5 arc min ͑90% confidence͒. The successful completion of this mirror demonstrates its applicability to future x-ray telescopes such as Constellation-X.
High sensitivity hard X-ray data by means of focusing optics is crucially important to investigat... more High sensitivity hard X-ray data by means of focusing optics is crucially important to investigate active galaxies and cluster of galaxies. We have developed focusing telescopes with platinum-carbon multilayer coatings. The energy band is broadened by multilayers with graded periodic length, so called `Supermirrors'. We were successful to obtain hard X- ray images in the energy band from 25 to 40 keV with a demonstration model of telescope with 20 mirror shells of supermirrors. The flight model of supermirror telescope is now in production for balloon flight in the summer of 2000. The current status of the balloon mission and future application of supermirror technology is discussed.
The ability of periodic and aperiodic multilayer structures to diffract x-rays at grazing angles ... more The ability of periodic and aperiodic multilayer structures to diffract x-rays at grazing angles has long been understood, and has been successfully exploited in the x-ray region, primarily on flat substrates. We have recently begun producing Pt/C multilayer coated thin foil mirrors for the InFOC(mu) S balloon mission. The mirrors are made by depositing the multilayer on glass mandrels and transferring the multilayer to the thin foil substrates using a replication process similar to that used for production of the recently lost ASTRO-E mirrors. Both periodic and broadband versions have been successfully replicated onto thin foils and characterized by grazing incidence x-ray scattering. Initial comparisons between mirrors deposited on flat float glass substrates and mirrors replicated onto thin foils indicate that the reflection properties of the multilayer are not damaged by the transfer from mandrel to foil. We describe the production and characterization facilities that have been developed in our lab, and the performance of our multilayer mirrors, with particular emphasis on the characterization of interfaces in the Pt/C system.
The CZT detector on the Infocus hard X-ray telescope is a pixellated solid-state device capable o... more The CZT detector on the Infocus hard X-ray telescope is a pixellated solid-state device capable of imaging spectroscopy by measuring the position and energy of each incoming photon. The detector sits at the focal point of an 8m focal length multilayered grazing incidence X-ray mirror which has significant effective area between 20--40 keV. The detector has an energy resolution of 4.0keV at 32keV, and the Infocus telescope has an angular resolution of 2.2 arcminute and a field of view of about 10 arcminutes. Infocus flew on a balloon mission in July 2001 and observed Cygnus X-1. We present results from laboratory testing of the detector to measure the uniformity of response across the detector, to determine the spectral resolution, and to perform a simple noise decomposition. We also present a hard X-ray spectrum and image of Cygnus X-1, and measurements of the hard X-ray CZT background obtained with the SWIN detector on Infocus.
Applied Optics, 2003
The International Focusing Optics Collaboration for Crab Sensitivity ͑InFOCS͒ balloonborne hard x... more The International Focusing Optics Collaboration for Crab Sensitivity ͑InFOCS͒ balloonborne hard x-ray telescope incorporates graded Pt͞C multilayers replicated onto segmented Al foils to obtain the significant effective area at energies previously inaccessible to x-ray optics. Reflectivity measurements of individual foils demonstrate our capability to produce a mass quantity of multilayered foils with a rms roughness of 0.5 nm. The effective area of the completed mirror is 78 and 22 cm 2 at 20 and 40 keV, respectively. The measured half-power diameter is 2.0 Ϯ 0.5 arc min ͑90% confidence͒. The successful completion of this mirror demonstrates its applicability to future x-ray telescopes such as Constellation-X.