TY  - GEN
UR  - https://archiv.ub.uni-heidelberg.de/volltextserver/18207/
Y1  - 2015///
ID  - heidok18207
AV  - public
TI  - Technologies for improving the precision of radial velocity measurements with high-resolution, fibre-fed échelle spectrographs
N2  - The objective of the dissertation is to investigate instrumental limitations of high-precision radial velocity measurements with fibre-fed échelle spectrographs and to
develop technologies to overcome these limitations. It is composed of two parts:
The first part investigates the optimal use of optical fibres to reduce the sensitivity of spectrographs to unstable coupling conditions at a telescope. In the framework of CARMENES, a high-resolution spectrograph project, optical properties of appropriate fibres are investigated with the aim of determining the optimal solution for the particular requirements of this instrument. Scrambling and focal ratio degradation behaviour of non-circular fibres are measured and optical simulations of the stability performance of CARMENES are presented. The results provide a strong indication that a 1 m/s radial velocity measurement precision, which is the goal of CARMENES, can be reached by combining an octagonal with a circular fibre.
The second part describes a novel method of stabilizing a broadband Fabry-Pérot etalon for spectrograph calibration. By using Doppler-free saturated absorption spectroscopy, a single etalon transmission peak is locked to hyperfine transitions of rubidium. For reasonable astronomical integration times, a locking precision of 3 cm/s is demonstrated.
KW  - Échelle Spektrograph
KW  -  Etalon
KW  -  Dopplerfreie Rubidiumspektroskopie
A1  - Stürmer, Julian
ER  -