High-resolution x-ray spectroscopy with superconducting tunnel junctions

✍ Scribed by P. Hettl; G. Angloher; F. v. Feilitzsch; J. Höhne; J. Jochum; H. Kraus; R. L. Mössbauer

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 106 KB
• Volume: 28
• Category: Article
• ISSN: 0049-8246
• DOI: 10.1002/(sici)1097-4539(199909/10)28:5<309::aid-xrs341>3.0.co;2-1

✦ Synopsis

An energy resolution of 1E = 12 eV (FWHM) was measured for the 55 Mn Ka 1 line (E = 5.90 keV) using a single superconducting Al/Al x O y /Al tunnel junction. The total detector area of 100×100 µm was illuminated, while a slit mask of about 150 µm width was used to shadow the detector leads and substrate area from the impinging x-rays. The total electronic noise contribution to the energy resolution was measured as 1E elec = 7 eV (FWHM). The process of tunnel junction fabrication was optimized towards a reproducible and high-quality growth of the tunnel barrier. High-quality aluminium films promote long quasi-particle lifetimes and ensure reproducible tunnel barrier growth. The residual resistance ratio of a 1 µm thick aluminium test film was about 100.