Study 000351:

ACRONYM: LANDI_SCAN_CH

Purpose: 
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The aim of this sequence (and of HOP 107) is to measure the dependence
of the ion temperature on the charge-over-mass ratio (Q/A) in polar coronal
holes as a function of distance from the limb. The Q/A ratio will be used to
test/validate theoretical models of fast solar wind acceleration that rely on
ion-cyclotron waves, along the guidelines of Landi & Cranmer 2009. This
investigation requires the observation of lines from a very large number
of different ions, and to maximize the number of ions
available it needs to be run in the same place and at the same time with a
full spectral scan from SOHO/SUMER.

Line intensities will be used to measure the electron density, the plasma
temperature distribution, and the element abundances of the plasma as a
function of distance from the limb.
Repeating the study in plumes and in interplume lanes is desired, the
60" E-W raster will allow us to observe both plasma structures within
the same scan.

The need to observe the line profiles and intensities for as many ions as
possible and for as many distances from the limb as possible in polar
coronal holes justifies the use of the full length of the
EIS slit. The wide 2" slit is selected as compromis between high-resolution
and large signal-to-noise ratio.

Target:          CH
Expsore time:    240 Second
slit:            2"
Step size:       2"
FOV:             60"x512"
Duration:        2h 7m 21s
Volume:          164 Mbits

Instruction to planners:
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Repeat the raster, when possible, to fill the available time slot. 

Pointing:
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The ideal pointing for this study is off-disk in polar coronal holes,
at the central meridian, to maximize the distance from the limb covered by
the slit. Pointing will be adjusted to include plume and interplume lanes. 

Warning:
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None