title: Fluctuation-limited noise in a superconducting transition-edge sensor.
abstract: In order to investigate the origin of the until now unaccounted excess noise and to minimize the uncontrollable phenomena at the transition in x-ray microcalorimeters we have developed superconducting transition-edge sensors into an edgeless geometry, the so-called Corbino disk, with superconducting contacts in the center and at the outer perimeter. The measured rms current noise and its spectral density can be modeled as resistance noise resulting from fluctuations near the equilibrium superconductor-normal metal boundary.
authors.affiliation: Department of Physics, University of Jyväskylä, P.O. Box 35 (YFL) FIN-40014 University of Jyväskylä, Finland.
authors.forename: A
authors.initials: A
authors.lastname: Luukanen
authors.forename: K M
authors.initials: KM
authors.lastname: Kinnunen
authors.forename: A K
authors.initials: AK
authors.lastname: Nuottajärvi
authors.forename: H F C
authors.initials: HF
authors.lastname: Hoevers
authors.forename: W M
authors.initials: WM
authors.lastname: Bergmann Tiest
authors.forename: J P
authors.initials: JP
authors.lastname: Pekola