Hannover 2013 – scientific programme
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A: Fachverband Atomphysik
A 20: Poster: Precision spectroscopy of atoms and ions (with Q)
A 20.21: Poster
Tuesday, March 19, 2013, 16:00–18:30, Empore Lichthof
A high resolution double imaging spectrometer for the investigation of ion emission in the solar corona — •Adalbert Ding1,2 and Shadia Rifai Habbal3 — 1Institut für Optik und Atomare Physik, TU Berlin — 2Institut für Technische Physik, Berlin — 3Institute for Astronomy, University of Hawaii, Honolulu, USA
Doppler shift of emission lines can be used to obtain information about the velocity of light emitting particles in the gas phase. An easily transportable optical spectrometer has been designed and set up for such uses in solar eclipse expeditions .
An echelle grating operated under grazing incidence in high order (appr. 40th) is used to significantly increase the resolution. A combination of optical cut-off filters and dichroic mirrors preselects a narrow wavelength range for order sorting. Two sets of such filters and two gratings allow the simultaneous measurement in two relevant wavelength ranges. The optical properties of the spectrometer have been chosen such that a 2 to 3 orders are simultaneously recorded with a low noise CCD-chip. This allows the deconvolution of the lines by using Fourier transform techniques.
By using an extended entrance slit it is possible to also record the intensity distribution along the slit which has been designed as a mirror. Thus it is possible to record the sun’s position with respect to the slit using a separate video camera.
First results - both from natural and artificial sources - will be presented. The influence of the spectrometer parameters and the camera noise of the deconvoluted spectra will be discussed.