The Tandem Etalon Magnetograph of the Solar Magnetic Activity Research Telescope (SMART) at Hida Observatory

The imaging photospheric magnetograph using tandem Fabry–Perot filters is newly installed in the Solar Magnetic Activity Research Telescope (SMART) of Hida Observatory, Kyoto University. The instrument, Tandem Etalon Magnetograph (TEM), consists of a rotating wave plate, tandem Fabry–Perot filters which scan the Fe i 6302.5 Å line with ∼ 130 mÅ bandwidth, a polarizing beam splitter, and two CCD cameras simultaneously taking orthogonally polarized light with a frame rate of 30 frames per second. We have confirmed that the Stokes vector map deduced from 20 s integration achieves a polarimetric sensitivity of ∼ 5 × 10⁻⁴ for all polarization states at one wavelength, which is higher than is achieved with a space instrument such as the Spectro-Polarimeter aboard Hinode or the Helioseismic and Magnetic Imager aboard the Solar Dynamic Observatory (SDO). We expect the complementary observations by SMART/TEM, Hinode, and SDO can shed new light on the trigger and energy storage mechanism of solar flares.