; ; ; ; ; ; ; ; ;
1 National Space Institute, Technical University of Denmark 2 Astrophysics, National Space Institute, Technical University of Denmark 3 Lawrence Livermore National Laboratory 4 Radiation Monitoring Devices Inc. 5 California Institute of Technology 6 Columbia University 7 Lawrence Livermore National Laboratory 8 California Institute of Technology 9 Columbia University
Recent technological innovations make it feasible to construct effcient hard x-ray telescopes for space-based astronomical missions. Focusing optics are capable of improving the sensitivity in the energy range above 10 keV by orders of magnitude compared to previously used instruments. The last decade has seen focusing optics developed for balloon experiments and they are implemented in approved space missions such as the Nuclear Spectroscopic Telescope Array (NuSTAR). The full characterization of x-ray optics for astrophysical missions, including measurement of the point spread function (PSF) as well as scattering and re ectivity properties of sub- strate coatings, requires a large area detector with very high spatial resolution and sensitivity, photon counting and energy discriminating capability. Novel back-Thinned Electron Multiplying Charge-Coupled Devices (EMC- CDs) are suitable detectors for ground-based calibrations if combined with a scintillating material. This optical coupling of the EMCCD chip to a microcolumnar CsI(Tl) scintillator can be achieved via a fiberoptic taper. Not only does this detector system exhibit low noise and high spatial resolution inherent to CCDs, but the EMCCD is also able to handle high frame rates. Additionally, thick CsI(Tl) yields high detection effciency for x-rays. In this paper, we discuss the advantages of using an EMCCD to calibrate hard x-ray optics. We will illustrate the promising features of this detector solution using examples of data obtained during the ground calibration of the NuSTAR telescopes performed at Columbia University during 2010/2011. Finally, we give an outlook on latest development and optimizations. © 2012 SPIE.
Proceedings of Spie, the International Society for Optical Engineering, 2012, Vol 8443
Calibration; Detectors; Gamma rays; Optical transfer function; Phosphors; Space telescopes; Spacecraft equipment; X rays
Main Research Area:
Space Telescopes and Instrumentation 2012: Ultraviolet to Gamma Ray