The SPICE Instrument
Stratospheric Particle Injection for Climate Engineering
SPICE is a high resolution imaging spectrometer operating at extreme ultraviolet wavelengths that will address the key science goals of Solar Orbiter by providing quantitative knowledge of the physical state and composition of the plasmas in the solar atmosphere, in particular investigating the source regions of outflows and ejection processes which link the solar surface and corona to the heliosphere.
SPICE is designed to study the structure, dynamics and composition of the transition region and corona by observing key emission lines on the solar disk on timescales from seconds to tens of minutes. A key aspect of the SPICE observing capability is the ability to quantify the spatial and temporal signatures of temperature and density tracers to unravel the inter-relationship between the chromosphere, coronal structures, coronal mass ejections, the solar wind and the low corona.
Observing the intensities of selected spectral lines and line profiles of two extreme ultraviolet (EUV) wavelength bands (70.4 – 79.0 nm / 97.3 – 104.9 nm), SPICE will derive temperature, density, flow and composition information of a wide range of plasmas (ionised atoms) formed in the Sun’s atmosphere at temperatures from 10’000 to 10’000’000 Kelvin.
SPICE Slit Change Mechanism
(Photo: Almatech SA)
Slit Change Mechanism (SCM)
Prime contractor: Almatech SA
Contract No. ALM-ACH-0776.15
The Slit Change Mechanism located at the heart of the SPICE instrument provides four interchangeable slits of different widths that are necessary for the dispersion of the light from the Sun. The image of the sun formed by the off-axis parabolic mirror is sent to the four slits. Each of the slits selects a portion of the solar image and passes it onto two detector arrays and can be individually selected into the active slit position depending upon the science activities to be conducted.