Optical capabilities of the Multichannel Subtractive Double Pass (MSDP) for imaging spectroscopy and polarimetry at the Meudon Solar Tower

Abstract

The Meudon Solar Tower (MST) is a 0.60 m telescope dedicated to spectroscopic observations of solar regions. It includes a 14-meter focal length spectrograph which offers high spectral resolution. The spectrograph works either in classical thin slit mode (R > 300000) or 2D imaging spectroscopy (60000 < R < 180000). This specific mode is able to provide high temporal resolution measurements (1 min) of velocities and magnetic fields upon a 2D field of view, using the Multichannel Subtractive Double Pass (MSDP) system. The purpose of this paper is to describe the capabilities of the MSDP at MST with available slicers for broad and thin lines. The goal is to produce multichannel spectra-images, from which cubes of instantaneous data (x, y, $\lambda$) are derived, in order to study of the plasma dynamics and magnetic fields (with polarimetry).