Jason Koglin, SPIE, August 2002 Development and production of hard X-ray multilayer optics for HEFT Caltech Space Radiation Laboratory Hubert Chen, Fiona Harrison * Currently at MIT Columbia Astrophysics Laboratory Jason Koglin, Jim Chonko, Mario Jimenez-Gerate *, Chuck Hailey, Mike Sileo, Marcela Stern, David Windt, Haitao Yu Danish Space Research Institute Finn Christensen, Carsten Jensen Lawrence Livermore National Laboratory Bill Craig, Todd Decker, Kurt Gunderson

Jason Koglin, SPIE, August 2002 HEFT Science  Imaging and spectroscopy of 44 Ti emissions and non-thermal continuum in young Supernova remnants  Sensitive hard X-ray observations of obscured Active Galactic Nuclei (AGN)  Spectroscopic observations of accreting high-magnetic field pulsars  Galactic Center: observe compact objects in outburst/quiescence NASA/CXC/SAO/Rutgers/J.Hughes NASA/CXC/SAO/H. Marshall et al. Einstein/F. R. Harnden (CfA) GRANAT

Jason Koglin, SPIE, August 2002 Instrument Overview  Conic-approximation Wolter-I optics: 6 m focal length  Thermally Formed Glass Substrate: 300 um thick  Depth-graded W/Si Multilayers: 20 – 70 keV  CdZnTe pixel detector resolution: 1 keV  Effective Area: 250 cm 40 keV  Over-constrained optics: 1’ HPD  Field of view: 20 keV  Pointing stability: 20” NASA/CXC/SAO

Jason Koglin, SPIE, August 2002 HEFT Flight Assembly

Jason Koglin, SPIE, August 2002 Thermally Formed Glass Thin and light weight developed for the flat panel industry Smooth and flat with low surface roughness (~3.5 Å ) Mass producible

Jason Koglin, SPIE, August 2002 Multilayer Coatings Enhanced reflectivity with broad energy acceptance at reasonable graze angles W/Si for first two HEFT modules – limited to 70 keV Ni-based for subsequent modules – extended to 100 keV High throughput at DSRI coating facility C. Jensen showed a poster on this facility D. Windt talk on > 100 keV multilayers today

Jason Koglin, SPIE, August 2002  ~ 8” assembly error contribution Telescope Assembly Method  Assembly errors do not stack up Colorado Precision Products  Each spacer layer (upper & lower) is individually machined to the precise radius and angle:  Only near net shaped shells are necessary to obtain 1’ HPD performance  Multilayer optic shells are constrained to spacers with epoxy:

Jason Koglin, SPIE, August 2002 Metrology Comparison LVDT UV Laser (pre-mounted) X-ray

Jason Koglin, SPIE, August 2002 HEFT Prototype 10 long cm segments used to form 20 cm layers Robust Process: If mounting errors occur, they are quickly attenuated and do not severely affect the overall performance.

Jason Koglin, SPIE, August 2002 Optics Development HPD = 31” 58” Prototype with 200  m thick glass 45” Prototype with 5 cm segments HPD = 30” Example:

Jason Koglin, SPIE, August 2002 Environmental Testing  Prototype optic tested in all three axes to the Delta IV qualification level vibration spectrum with no apparent degradation to the glass (lowest natural frequency of the glass between supports is ~700 Hz).  Expected shock load from parachute: 10 g’s  Mounting system designed to attenuate shock through passive damping and compliant structural supports  Damage potential for high shock load > 25 g’s  Reasonable safety margin for optics to survive multiple balloon campaigns

Jason Koglin, SPIE, August 2002 HEFT Sample Metrology

Jason Koglin, SPIE, August 2002 Conclusions  Demonstrated consistency of X-ray, UV & LVDT metrology methods.  Assembly machine error (~8”) does not significantly effect HEFT performance – performance limited by glass substrates.  54” HEFT prototype optic using 300  m thick glass substrates.  First HEFT flight optic currently being built at CPPI.  Preparing balloon campaign for next year.