| Name: | Radhika Dharmadhikari |
| Affiliation: | Indian Institute of Astrophysics |
| Conference ID : | ASI2023_116 |
| Title : | Development of an Alignment Device for the Prototype Segmented Mirror Telescope |
| Authors : | Radhika Dharmadhikari, Padmakar Parihar, Muthahar, Govinda KV, Kemkar PMM, Himanshu Kunjam, Sonam Jorphail, Tsewang Stanzin, Sandeep DS, Abhishek Goudar |
| Mode of Presentation: | Oral |
| Abstract Category : | Instrumentation and Techniques |
| Abstract : | The Prototype Segmented Mirror Telescope (PSMT) is a 1.3m, seven segment telescope, being developed as a technology demonstrator for India’s large optical-IR telescope project. For the segmented mirror to work like a single monolithic, it is important for the segments to be very precisely aligned. The alignment process includes co-aligning (removal of tip-tilt error), co-focusing (removal of defocus error) and co-phasing (removal of height difference between adjacent segments) of the segments. For the PSMT, a Shack Hartmann sensor based alignment device has been designed and developed. The device will be used to measure the tip-tilt and defocus errors of the individual segments, thus enabling the co-aligning and co-focusing. The device is designed to work in two different modes, Shack-Hartmann mode and the imaging mode. After completion of the alignment procedure, the final image quality can be checked in the imaging mode. To make the device cost effective, only off the shelf components are used. The optical design and analysis for the device have been carried out using ZEMAX. After completing extensive laboratory experimentation on the optical bench, the device is finally assembled in a custom designed and built mechanical unit and tested. A large format CMOS camera is used for imaging purpose and device uses 3 stepper motors based actuators. The control software is developed in the Python programming language. I would present the opto-mechanical design details as well as preliminary experimental results obtained from the device. |
