Concept study X-ray testing for NICER’s X-ray concentrators Erin Balsamo a,b,c , Keith Gendreau b , Zaven Arzoumanian b,c,d , Takashi Okajima b , Lalit Jalota a,b,c , Yang Soong b,c,d , Peter Serlemitsos b , Teruaki Enoto k,b , Bhalvinder Gulati b , Steve Kenyon b , Devin Hahne j , David Fickau e , Nicholas Spartana e , Steve Lentine f , Ceili Burdhimo g , Billy Barrios h , Lisa Wu i a University of Maryland, Baltimore County, Baltimore, MD; b NASA Goddard Space Flight Center, Greenbelt, MD; c Center for Research and Exploration in Space Science and Technology, Baltimore, MD; d Universities Space Research Association, Greenbelt, MD; e Stinger Ghaffarian Technologies, Greenbelt, MD; f Rensselaer Polytechnic Institute, Troy, NY; g Massachusetts Institute of Technology, Cambridge, MA; h California State University, Los Angeles, CA; i Urbana High School, Ijamsville, MD; j Johns Hopkins Applied Physics Laboratory, Laurel, MD; k High Energy Astrophysics Laboratory, Institute of Physical and Chemical Research (RIKEN), Wako, Saitama, Japan; ABSTRACT We performed a series of measurements using X-rays to assess the current performance of the Neutron star Interior Composition ExploreR (NICER) X-ray concentrators during the mission’s concept study stage. NICER will use 56 grazing-incidence X-ray concentrators in the optical system with each module focusing the incoming photons to co-aligned silicon drift detectors with 2 mm apertures. Successful X-ray timing and navigation studies require optimal signal to noise, thus by optimizing high throughput concentrators with a large collecting area we can minimize the PSF and reduce the detector aperture size, reducing background. The performance measurements were conducted in a 600 meter X-ray beamline which collimated photons from a soft X-ray source to an X-ray CCD which was used as the detector. Several engineering test units were used to perform these studies by measuring the effective area, on and off-axis resolution, and to assess the effects of a vibration test on the module’s optical performance. We have shown that the concentrators have made significant progress towards exceeding NICER’s final goals. Keywords: NICER, X-ray concentrators, X-ray optics, foil X-ray mirrors, X-ray astronomy, pulsars, neutron stars 1. INTRODUCTION The Neutron star Interior Composition ExploreR (NICER) 1 is an approved NASA Explorer Mission of Opportu- nity dedicated to the study of extreme physics of neutron stars through soft X-ray timing spectroscopy. Neutron stars contain exotic states of matter with material density and pressure higher than that of an atomic nuclei with extraordinary gravitational, electromagnetic, and nuclear-physics environments. NICER will explore these properties to constrain theoretical models of the equation of state by measuring the masses and radii of neutron stars to a higher precision than available with current instrumentation. Scheduled for launch in December 2016, NICER will be an International Space Station (ISS) payload designed to comply with the environment on board the space station. To meet NICER’s scientific goals, the optics must collect photons efficiently from relatively faint sources while minimizing all possible sources of background, both instrumental and cosmic. Since the science goals only Further author information: balsamo1@umbc.edu Optics for EUV, X-Ray, and Gamma-Ray Astronomy VI, edited by Stephen L. O'Dell, Giovanni Pareschi, Proc. of SPIE Vol. 8861, 88611M · © 2013 SPIE CCC code: 0277-786X/13/$18 · doi: 10.1117/12.2024108 Proc. of SPIE Vol. 8861 88611M-1 Downloaded From: http://proceedings.spiedigitallibrary.org/ on 02/23/2015 Terms of Use: http://spiedl.org/terms