Search

Your search keyword '"Takada, Susumu"' showing total 39 results
Start Over Author "Takada, Susumu" Journal japanese journal of applied physics
39 results on '"Takada, Susumu"'

20. Properties of Large-Sized Nb-Based Superconducting TunnelJunctions for X-Ray Detection

Author

Takeno, Kazuhiko, primary, Ishibashi, Kenji, additional, Mori, Ken-ichi, additional, Nagae, Toshimitsu, additional, Matsumoto, Yuzuru, additional, Katase, Akira, additional, Kinoshita, Chiken, additional, Nakai, Kiyomichi, additional, Takada, Susumu, additional, Nakagawa, Hiroshi, additional, Akoh, Hiroshi, additional, Aoyagi, Masahiro, additional, and Kohjiro, Satoshi, additional

Published
1991
Full Text
View/download PDF

35. YBa2Cu3OxCrossover Structures Using CeO2Film as Insulating Layer

Author

Sato, Hiroshi, Miyakawa, Ryuji, Nakamura, Norito, Gj\oen, Stein R., Hiroshi Akoh, Hiroshi Akoh, and Susumu Takada, Susumu Takada

Abstract

We have fabricated YBa2Cu3Ox(YBaCuO) crossover structures using CeO2films as insulating layers, varying the area from 10×50 to 50×50 µm2. The fabrication process of the crossover structure was performed ex situ, by combining the deposition of YBaCuO and CeO2films with the microfabrication of YBaCuO bridges and contact holes in the CeO2layer using a liquid-nitrogen-cooled dry etching method. Even though we used ex situprocesses, the bottom YBaCuO bridges had a transition temperature Tcof 87 K and a critical current density Jcof 1.0×105A/cm2at 77 K. Typical crossover resistivity was more than 2.0×108?·cm below 80 K even for 50×50 µm2structures. This indicates that CeO2is a promising material for insulating layers in high-Tcsuperconducting devices.

Published
1996
Full Text
View/download PDF

36. Anisotropy in the Magnetic Penetration Depth of (103)YBa2Cu3O7-xThin Films

Author

Kohjiro, Satoshi, Tachino, Tetsuya, Hiroshi Akoh, Hiroshi Akoh, and Susumu Takada, Susumu Takada

Abstract

The anisotropy in the magnetic penetration depth ? at 4.2 K has been systematically investigated with (103)-oriented YBa2Cu3O7-xthin films, using the resonator technique in transmission lines. The obtained values are ?=1.4±0.4 µm and ?=400±130 nm for the current flow across and parallel to Cu-O planes, respectively. This anisotropy ratio is in good agreement with the value estimated from the anisotropic resistivities of the films.

Published
1991
Full Text
View/download PDF

37. Injection-Detection Experiments to Study Diffusion Processes in Nb film using a Three Terminal in-planeSuperconducting Double-Tunnel Junctions

Author

Parlato, Loredana, Ammendola, Giuseppe, Peluso, Giuseppe, Pepe, Giovanni Piero, Esposito, Emanuela, Nakagawa, Hiroshi, Akoh, Hiroshi, and Takada, Susumu

Abstract

Superconducting Tunnel Junctions are promising devices in next generation nuclear and optical detectors. Unfortunately, a number of relaxation processes in the number of initially produced excitations degrades the performances of such devices. In order to investigate the role of charge loss mechanisms in Nb and/or at the Nb/Si interface we have fabricated three terminal in-planedouble tunnel junctions, in which quasi-particles are injected into a Nb common strip and detected at different distances by tunnel junctions. The detection efficiency ? decreases of about one order of magnitude from T=4.2K to T=1.2K for any injector-detector distance. The presence of charge trapping centers, activated at low temperatures, can qualitatively explain such a result. The estimation of the quasi-particle diffusion constant D=28±5 cm2/s at T=1.2 K is in agreement with other similar values reported in literature.

Published
1998
Full Text
View/download PDF

38. Effect of the Critical Current Density and the Junction Size on the Leakage Current of Nb/Al-AlOx/NbSuperconducting Tunnel Junctions for Radiation Detection

Author

Joosse, Koen, Nakagawa, Hiroshi, Akoh, Hiroshi, Takada, Susumu, Maehata, Keisuke, and Ishibashi, Kenji

Abstract

Nb/Al-AlOx/Nb superconducting tunnel junctions (STJ's) designed for X-ray detection have been fabricated. The behavior of the low-temperature subgap leakage current, which severely limits the energy resolution obtained in such devices, is investigated. From trends in the dependence of the leakage currents on the critical current density and the size of the STJ, as well as from the low-temperature current-voltage characteristics, and an analysis of the base electrode surface morphology, it is concluded that physical defects in the barrier region are the most probable cause of the leakage currents. Suggestions are given for optimization of the device processing.

Published
1996
Full Text
View/download PDF

39. Fourier Transform Optical Imaging Using SAW Memory-Correlator

Author

Takada, Susumu and Hayakawa, Hisao

Abstract

A novel optical imaging method by using a memory-correlator in which a laser pulse acts to store wideband surface wave signals in surface states of a semiconductor is described. The Fourier transform technique is used to scan optical images by storing a chirp surface wave signal and an optical pattern simultaneously, which can improve a dynamic range and a signal-to-noise ratio in comparison with a single scan pulse method.

Published
1978
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results