The Noise and Energy Resolution of the Ti/Au Bilayer X-ray TES Calorimeter with an Au Absorber

• Published in: Journal of low temperature physics Vol. 151; no. 1-2; pp. 185 - 189
• Main Authors: Yoshino, T., Mukai, K., Ezoe, Y., Yamasaki, N. Y., Mitsuda, K., Kurabayashi, H., Ishisaki, Y., Takano, T., Maeda, R.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.04.2008
• Subjects: Characterization and Evaluation of Materials; Condensed Matter Physics; Magnetic Materials; Magnetism; Physics; Physics and Astronomy; Transition-edge sensor; Microcalorimeter; 85.25.Oj; TES; Au absorber; 07.85.Fv; 07.20.Fw
• ISSN: 0022-2291; 1573-7357
• DOI: 10.1007/s10909-007-9617-1

We fabricated the TES microcalorimeter with TES(Ti/Au) and gold absorber, and obtained FWHM energy resolution of 4.8±0.3 eV at 5.9 keV. The baseline resolution, i.e. the resolution determined by noise, was 4.1±0.1 eV. From the noise spectra we found that the square of the baseline resolution could be approximately decomposed into contributions of three noise components. They are estimated to be (2.5 eV) 2 (the intrinsic noise), (1.5 eV) 2 (the readout noise), and (3.0 eV) 2 (so-called excess noise). There is additional broadening of (2.5 eV) 2 from the baseline resolution. The excess noise is the largest limiting factor of the energy resolution of the device.