High quality Nb-based tunnel junctions with surface area of 200 × 200 μm2 as well as 100×100 mm2 were tested by irradiation of 5.9 keV x-rays. The 200×200 μm2 junction exhibited better x-ray response than that of 100 × 100 μm2 one. The operation of the 200×200 μm2 junction was tested by applying a magnetic field with different ramping speeds. Two kinds of stable operation modes with different pulse height distributions were found. In the higher pulse-height mode, the junction detected 5.9 keV x-rays of 55Mn with an energy resolution (FWHM) of 93 eV, and the energy required for single electron collection was 6.5 meV. The 200×200 μm2 junction has the largest dimension among tunnel junctions exceeding Si-semiconductor detectors in energy resolution.
|Number of pages
|Denshi Gijutsu Sogo Kenkyusho Iho/Bulletin of the Electrotechnical Laboratory
|Published - 1997
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Electrical and Electronic Engineering