A millimeter-wave observation of solar flares directly from outside the Earth’s atmosphere (i.e., space-based) has never been attempted yet. Nonetheless, this methodology could open several interesting perspectives. First, the Sun could be studied with high time-on-target, high temporal resolution, and good sensitivity. As a consequence, a large sample of millimeter flare could be obtained. These data, equivalent to several years of equivalent observations from ground-based radiotelescopes, could be used in order to address several outstanding scientific questions regarding particle acceleration and transport in the solar corona. Is there more than one population of accelerated electrons, implying two acceleration mechanisms? What is the energy spectrum of the highest energy electrons? Are there very short (subsecond) pulses of acceleration? Second, the same methodology could also be used to study the relationship between solar flares and coronal mass ejections, the latter having effects on space weather, near-Earth conditions, and telecommunications. This chapter will explore the above possibility by proposing a feasibility study of a full solar disk radiometer operating at the frequency of 90GHz. Such an apparatus will be referred to as the Millimeter-wave Instrument for the Observation of the Sun (acronym: MIOS). The chapter is organized as follows. First the scientific backgrounds and the motivations will be discussed. Then the characteristics of both quiet-Sun and solar flare radiation at millimeter-wave will be illustrated. Finally, the MIOS system-level design will be addressed.
MIOS: Millimeter Wave Radiometers for the Space-Based Observation of the Sun
ALIMENTI, Federico;BATTISTINI, ANDREA;PALAZZARI, VALERIA;ROSELLI, Luca;
2012
Abstract
A millimeter-wave observation of solar flares directly from outside the Earth’s atmosphere (i.e., space-based) has never been attempted yet. Nonetheless, this methodology could open several interesting perspectives. First, the Sun could be studied with high time-on-target, high temporal resolution, and good sensitivity. As a consequence, a large sample of millimeter flare could be obtained. These data, equivalent to several years of equivalent observations from ground-based radiotelescopes, could be used in order to address several outstanding scientific questions regarding particle acceleration and transport in the solar corona. Is there more than one population of accelerated electrons, implying two acceleration mechanisms? What is the energy spectrum of the highest energy electrons? Are there very short (subsecond) pulses of acceleration? Second, the same methodology could also be used to study the relationship between solar flares and coronal mass ejections, the latter having effects on space weather, near-Earth conditions, and telecommunications. This chapter will explore the above possibility by proposing a feasibility study of a full solar disk radiometer operating at the frequency of 90GHz. Such an apparatus will be referred to as the Millimeter-wave Instrument for the Observation of the Sun (acronym: MIOS). The chapter is organized as follows. First the scientific backgrounds and the motivations will be discussed. Then the characteristics of both quiet-Sun and solar flare radiation at millimeter-wave will be illustrated. Finally, the MIOS system-level design will be addressed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
