Comparison of the Effects of Magnetic Field on Low Noise MoAu and TiAu TES Bolometers

Recently we have reported on the effects of magnetic field on our low noise (NEP = 4 $$\times 10^{-19}$$ W/ $$\surd $$ Hz) [1] TiAu TES bolometers that are being developed at SRON for the SAFARI FIR Imaging Spectrometer on SPICA telescope that will be operated in three different wavelength bands: S-band for 30–60 $$\upmu \hbox {m}$$ , M-band for 60–110 $$\upmu \hbox {m}$$ and L-band for 110–210 $$\upmu \hbox {m}$$ . The arrays for the S- and M- band will be based on TiAu TES bolometer arrays, developed by SRON. The L-band array will be based on a MoAu TES bolometer developed by University of Cambridge. We have investigated the effect of the magnetic field on the current, responsivity, speed and critical current for both the TiAu and MoAu TES bolometers in our high accuracy magnetic field set-up. A clear difference in weak link behavior is observed between the two types of TES bolometers in both strength of the effect and period of the oscillations.