POST-prototype for the Chinese Large Solar Telescope

For a better understanding of small-scale solar activities, the Chinese Large Solar Telescope (CLST) with a 1.8-m aperture was proposed in 2011. As the first open solar telescope in China, it has some technical challenges that need to be addressed (e.g., thermal controlling for the primary mirror, cooling for the heat stop, system assembly, etc.). To support the design of CLST, a prototype of an open solar telescope (POST) with a 600-mm aperture was designed and fabricated from 2014 to 2017. A series of experiments for technical verifications were carried out based on the POST. The design, integration, and experiments done with the POST are reviewed. The solar observation results during its first commissioning phase are also presented. (C) 2019 Society of Photo-Optical Instrumentation Engineers (SPIE)