Development and production of hard X-ray multilayer optics for HEFT

The High Energy Focusing Telescope (HEFT) will observe a wide range of objects including young supernova remnants, active galactic nuclei, and galaxy clusters at energies between 20 and 70 keV. Large collecting areas are achieved by tightly nesting layers of grazing incidence mirrors in a conic approximation Wolter-I design. The segmented mirrors that form these layers are made of thermally formed glass substrates coated with depth-graded multilayer films for enhanced reflectivity. The mirrors are assembled using an over-constraint method that forces the overall shape of the nominally cylindrical substrates to the appropriate conic form. We will present performance data on the HEFT optics and report the current status of the assembly production

Development of precision hard x-ray multilayer optics with sub-arcminute performance

A new generation of hard X-ray telescopes using focusing optics are poised to dramatically improve the sensitivity and angular resolution at energies above 10 keV to levels that were previously unachievable by the past generation of background-limited collimated and coded-aperture instruments. Active balloon programs (HEFT, InFocus), possible Explorer-class satellites, and major X-ray observatories (Constellation-X, XEUS) using focusing optics will play a major role in future observations of a wide range of objects including young supernova remnants, active galactic nuclei, and galaxy clusters. These instruments call for grazing incidence optics coated with depth-graded multilayer films to achieve large collecting areas. To accomplish the ultimate goals of the more advanced satellite missions such as Constellation-X, lightweight and low-cost substrates with angular resolution well below an arcminute must be developed. Recent experimental results will be presented on the development of improved substrates and precision mounting techniques that yield sub-arcminute performance

Hard x-ray optics: from HEFT to NuSTAR

Focusing optics are now poised to dramatically improve the sensitivity and angular resolution at energies above 10 keV to levels that were previously unachievable by the past generation of background limited collimated and coded-aperture instruments. Active balloon programs (HEFT), possible Explorer-class satellites (NuSTAR - currently under Phase A study), and major X-ray observatories (Con-X HXT) using focusing optics will play a major role in future observations of a wide range of objects including young supernova remnants, active galactic nuclei, and galaxy clusters. These instruments call for low cost, grazing incidence optics coated with depth-graded multilayer films that can be nested to achieve large collecting areas. Our approach to building such instruments is to mount segmented mirror shells with our novel error-compensating, monolithic assembly and alignment (EMAAL) procedure. This process involves constraining the mirror segments to successive layers of graphite rods that are precisely machined to the required conic-approximation Wolter-I geometry. We present results of our continued development of thermally formed glass substrates that have been used to build three HEFT telescopes and are proposed for NuSTAR. We demonstrate how our experience in manufacturing complete HEFT telescopes, as well as our experience developing higher performance prototype optics, will lead to the successful production of telescopes that meet the NuSTAR design goals

Development and production of hard X-ray multilayer optics for HEFT

The High Energy Focusing Telescope (HEFT) will observe a wide range of objects including young supernova remnants, active galactic nuclei, and galaxy clusters at energies between 20 and 70 keV. Large collecting areas are achieved by tightly nesting layers of grazing incidence mirrors in a conic approximation Wolter-I design. The segmented mirrors that form these layers are made of thermally formed glass substrates coated with depth-graded multilayer films for enhanced reflectivity. The mirrors are assembled using an over-constraint method that forces the overall shape of the nominally cylindrical substrates to the appropriate conic form. We will present performance data on the HEFT optics and report the current status of the assembly production