Abstract
We report recent progresses on the fabrication of pre-collimators (PCs). The PCs are designed to mitigate stray lights for X-ray telescopes to be onboard ASTRO-H. Each PC consists of cylindrical aluminum shells (blades) wiht varying radii of 60-225 mm, alignment frames to guilde the blade positions, and the bade housing body. The alignment frame and the housing are made of Aluminum 6061 and 7075 alloy, respectively. Heat-forming process is introduced to the production to stabilize the blade shape in orbit. Precise curvature of radius (tolerance of 1mm) and the linearity along with the direction of incident X-rays (P.V. < 20 microns) ensure that the blades do not obscure the telescope aperature. Each PC blade is placed precisely on top of the respective reflector mirror shell to reduce off-axis X-ray photons that leads to a "ghost" image within the detector field of view. In September 2010, the PC design--its height, thickness, and material of blades--was fixed and we produced the engineering model (EM) for the Soft X-ray Telescopes (SXTs). Since then, vibration tests for the EM PC unit are carried out twice, verifying that the PC has sufficient structural strength to withstand severe conditions during its launch. The EM PC is also installed onto the SXT mirror housing fabricated at the NASA's GSFC to validate our PC assembly method without any loss of thetelescope's effective aperture area. Since August 2011, we have been manusfacturing the PC blades for the flight models. We hereby show the manufacturing processes and also results of stray-light measurement without PCs for the SXT EM (obtained at ISAS 30m beamline facility) and the HXT FM (obtained at SPring-8 synchrotron radiation facility).
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.