Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
1 m2 mirror technology • AIM • find a suitable technology for large reflecting surface • reduce the overall cost with respect the current tecnology • Improve or maintain the actual optical quality • Avoid the use of panels for Active Mirror Controls • Develop technologies for very large reflectors
Front plate Honeycomb sandwich Magic I technology: pre-milling
Panel assembling in Eching Adjustment legs screwed on the mirror Cabling of the mirror for internal heater 2 mirrors mounted on a panel
Pre-alignment of a mirror in a panel A panel in the alignment tripod
Alignment tools Artificial parallel beam source Rotating tripod for panel alignment
Final alignment Final spot of a panel after The precise alignment of the mirrors 4 mirrors spots after the pre-alignment close to the virtual center of the MAGIC camera
1 m mirror Large single mirror vs 4 small mirrors in a panel 50 cm mirrors • 4 mirrors: • better optics • more labor + expensive panel needed • hand made first aligment (+?) • many high tech elementsto build a panel • Diamond turning prooven technology • Single large mirror: • Astigmatism important at large radii • Self supporting ->no panel needed • No manual alignment necessary • Big labor for the premilling • Diamond turning OK AMC motors
Ongoing R&D in Padova • Built 1m mirror with native spheric shape • aluminum sandwich glued on a spheric mould Front plate Mirror box + honeycomb mould
Ongoing R&D in Padova • Built 1m mirror with native spheric shape • aluminum sandwich glued on a spheric mould
Ongoing R&D in Padova 6 Prototype produced in 2005: Light weight : <18 Kg, to be installed in the telescope without any support panel.
Diamond milling first round • - Good reflectivity • Bad sphere ~ donuts: • Error in the alignment of • Diamond tool
Diamond milling second round Almost a perfect sphere. The rigidity of the new mirrors and the tune-up of the milling machine are now delivering very good results: The technique is becoming reliable
Impact of 1m2 in the reflector optical quality Full simulation is needed: modification of reflector program. hybrid combination: rings with small mirrors combined with rings with large mirrors (Denis & Michele) Option of 2 radii of curvature for outer rings: -technique to be proven but promising -need 60 Keuro of investments drawbacks -> not easy task to measure and check the optical quality. -> each mirror will become “unique” in the reflector
Production costs • Raw blank: • Pre-production • Production (1+/day in pipeline)