Afterword
175
properties of superconductors in lectures on electromagnetism and decided to publish
a textbook in which superconductivity was introduced. This was quite successful,
especially in terms of strengthening the present E-B analogy in electromagnetism.
When the administrative work was over, the author engaged in writing this textbook.
The textbook was then published, and the English edition entitled “Flux Pinning in
Superconductors” was also published.
Later, the author published the main points of the longitudinal magnetic field
effect through a newspaper. A newspaper reporter asked about the possibility of
application of this effect. The author answered that the superconducting power cable
would be a candidate. Several days later, an officer of the incubation center of the
Institute asked the author about the possibility of this application, followed by a
practical investigation of the new superconducting power cable. The principle of
the cable is explained in Chap. 7. It was quite lucky for the author, who studied in
the group of Profs. Irie and Yamafuji, to be engaged in a practical application of
superconductivity.
Just before his retirement from Kyushu Institute of Technology, the author felt
that it was necessary to unify the theories of flux pinning by Prof. Fujio Irie and Prof.
Kaoru Yamafuji into a comprehensive structure. The flux pinning theory of Prof.
Yamafuji was already proved many years ago, including the threshold problem by
using the statistical method. Then, the critical state model was derived theoretically
using first principles. Although each flux pinning theory was separately proved, the
statistical summation theory and the critical state theory were still not yet unified.
Then, the pinning loss power density was calculated, using the time average equivalent to the statistical average in the former theory, and it was shown that the obtained
relationship between the pinning loss power density and the pinning force density
was the same as that assumed in the critical state model. Thus, the theories published
in 1967 by two professors ([3] and [13] in Chap. 5) could be completely unified, and
the author could repay them.
Finally the author would like to thank Ms. Kaori Ono for drawing electronic figures
and Dr. Tania M. Silver at Wollongong University for correction of the English in
the book.
175
properties of superconductors in lectures on electromagnetism and decided to publish
a textbook in which superconductivity was introduced. This was quite successful,
especially in terms of strengthening the present E-B analogy in electromagnetism.
When the administrative work was over, the author engaged in writing this textbook.
The textbook was then published, and the English edition entitled “Flux Pinning in
Superconductors” was also published.
Later, the author published the main points of the longitudinal magnetic field
effect through a newspaper. A newspaper reporter asked about the possibility of
application of this effect. The author answered that the superconducting power cable
would be a candidate. Several days later, an officer of the incubation center of the
Institute asked the author about the possibility of this application, followed by a
practical investigation of the new superconducting power cable. The principle of
the cable is explained in Chap. 7. It was quite lucky for the author, who studied in
the group of Profs. Irie and Yamafuji, to be engaged in a practical application of
superconductivity.
Just before his retirement from Kyushu Institute of Technology, the author felt
that it was necessary to unify the theories of flux pinning by Prof. Fujio Irie and Prof.
Kaoru Yamafuji into a comprehensive structure. The flux pinning theory of Prof.
Yamafuji was already proved many years ago, including the threshold problem by
using the statistical method. Then, the critical state model was derived theoretically
using first principles. Although each flux pinning theory was separately proved, the
statistical summation theory and the critical state theory were still not yet unified.
Then, the pinning loss power density was calculated, using the time average equivalent to the statistical average in the former theory, and it was shown that the obtained
relationship between the pinning loss power density and the pinning force density
was the same as that assumed in the critical state model. Thus, the theories published
in 1967 by two professors ([3] and [13] in Chap. 5) could be completely unified, and
the author could repay them.
Finally the author would like to thank Ms. Kaori Ono for drawing electronic figures
and Dr. Tania M. Silver at Wollongong University for correction of the English in
the book.