L. Alha, J. Huovelin, J. Nevalainen
In this paper we present simulated solar coronal X-ray observations to verify
the sensitivity of a new hypothetical instrument design. These simulations are
folded through this X-ray spectrometer having a moderate size circular field of
view of 1.6 degrees. This SCXM (Solar Coronal X-ray Mapper) is designed to
compose of a single pixel silicon PIN detector equipped with a single
reflection double frustum X-ray optics. A moderate FoV would enable a
morphological study of the expanded X-ray emission from the solar corona during
a high activity of the Sun. The main scientific task of SCXM would be the
mapping of the coronal X-ray emission, i.e. to resolve the radial distribution
of the X-ray surface brightness around the Sun. These kind of off-limb
observations would help to interpret the coronal plasma diagnostics as a
function of the elongation angle. Direct solar full disc observations could be
also performed with SCXM. In this work we have applied real solar coronal X-ray
data obtained by the SMART-1 XSM (X-ray Solar Monitor) to simulate on-solar
observations at different flux levels to derive full disc sensitivity and
performance of SCXM. A challenging attempt for SCXM would also be to
distinguish the X-ray spectrum of the decaying axions around the Sun. These
axions are assumed to be created as side products of fusion reactions in the
core of the Sun. These axions are predicted to be gravitationally trapped to
orbit the Sun forming a halo-like X-ray emitting object. No signature of an
axion X-ray emission around the Sun has been observed to this day. This simple
X-ray spectrometer with an optical concentrator would be an inexpensive
instrument with low mass and telemetry budgets compared with more accurate
X-ray instruments of imaging capability. Hence SCXM would be an advanced choice
as an auxiliary instrument for solar coronal X-ray observations.
View original:
http://arxiv.org/abs/1111.6072
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