A laboratory evaluation unit of the spectrometer assembly consisting of the structure equipped with breadboard models of the entrance slit assembly, a grating drive mechanism mounting a toroidal grating and a MAMA detector has been integrated and aligned. Both tests with visible and UV radiation have been performed. Aberration and stray light measurements have shown satisfactory performances of the instrument almost in compliance with the scientific requirements. Esser, R. 1994, Space Sci. Some of the main problems of solar wind expansion are addressed.
Emphasis is placed on solar wind acceleration and the mass flux problems.
It is demonstrated how these two properties of the flow depend on other plasma parameters such as temperature, density and helium abundance. The importance of placing constraints on a given solar wind flow in the inner corona and at larger distances from the sun simultaneously, is also shown. Whether and how these constraints can be derived from observations carried out by SOHO instruments is then discussed. Both tests with visible and UV radiation have been performed. Aberration and stray light measurements have shown satisfactory performances of the instrument almost in compliance with the scientific requirements.