Fiber bolometer and emitter with negligible reflection for second sound measurements near the λ-point
✍ Scribed by Dmitry Rinberg; Michael L. Rappaport
- Publisher
- Elsevier Science
- Year
- 2001
- Tongue
- English
- Weight
- 121 KB
- Volume
- 41
- Category
- Article
- ISSN
- 0011-2275
No coin nor oath required. For personal study only.
✦ Synopsis
Superconducting Pb±Au thin ®lm bolometers for second sound (SS) measurements near the k-point have been made on 8 lm diameter glass ®bers. The small diameter of the ®bers provides negligible cross-section to SS waves as close as $10 À5 K to the kpoint (for f 10 kHz), thus eliminating re¯ections that may unduly complicate the wave distribution in the experimental cell. The bolometers have isotropic sensitivity to SS waves in the plane perpendicular to the ®ber. The operating temperature of the bolometers can be adjusted by changing an external magnetic ®eld and/or by varying the bias current, while still maintaining a ®gure of merit of $30. A SS emitter producing planar waves was made using the same ®bers.