Extension of the LTP temperature diagnostics to the LISA band: first results

Abstract

High-resolution temperature measurements are required in the LTP, i.e., 10 uK/sqrt(Hz) from 1 mHz to 30 mHz. This has been already accomplished with thermistors and a suitable low noise electronics. However, the frequency range of interest for LISA goes down to 0.1 mHz. Investigations on the performance of temperature sensors and the associated electronics at frequencies around 0.1 mHz have been performed. Theoretical limits of the temperature measurement system and the practical on-ground limitations to test them are shown demonstrating that 1/f noise is not observed in thermistors even at frequencies around 0.1 mHz and amplitude levels of 10 uK/sqrt(Hz).