158
7 Concluding Remarks
7.2 Superconductor Technology in the Future
Superconductivity has significantly contributed to the progress in solid state physics
in the 20th century. As described in this book, superconductors are common materials and are classified as one of the fundamental magnetic materials in electromagnetism. These are typical materials that show irreversibility in magnetic hysteresis
from the viewpoint of thermodynamics. Some new physics may also be based on
superconductors. Thus, superconductors are attractive substances.
The property of superconductors that the resistivity is zero under static conditions
is not only interesting from the viewpoint of physics, but also attractive from that of
application. The area of application that the superconductor technology using zero
resistivity can cover is widely spread over various fields, including power applications, energy saving, the environment, transportation systems, industrial technology,
medicine, etc. In addition, it extends even to the field of electronics, using its inherent
nonlinear properties (see Fig. 7.1). Information technology was a part of electronics in
former times, although it deeply penetrates all fields of technology now, and research
and industry in each field can no longer exists without it. Even an important wide
area in people’s daily life, such as telecommunications, distribution, and medical
services, is supported by information technology. Superconductor technology is also
a similar but slightly different technology that supports society, and it is expected to
support even high-level information technology.
In this section the application of superconductor technology in the fields of medical
treatment, environment, transportation, and energy will be briefly introduced.
(1) Medical treatment
The application of superconductors to medical treatments is roughly classified into
two categories from the viewpoint of technology. One of them is the application of
flux pinning phenomena, which is similar to other applications in the fields of energy
and environment, and the other is the application of the Josephson effect, which has
not been introduced in this book.
The most widely used type of equipment in the first category comprises the
magnetic resonance imaging (MRI) systems mentioned in Chap. 1. Very strong and
stable magnetic fields can be produced by superconducting magnets operated in
persistent current mode, which makes it possible to visualize clear cross-sections
of human body using the nuclear magnetic resonance technique. Open-type MRI
systems that reduce the anxiety of subjects are likely to become popular in the near
future.
Another system using superconducting magnets is heavy ion therapy for cancer
treatment. This is similar to a technique used in particle physics, where heavy ions
accelerated by a strong magnetic field are used to directly irradiate tumor cells with
high precision. In particular, a rotating gantry can irradiate the tumor while directing
the beam from an arbitrary direction, and hence, the subject’s body can remain in a
fixed position, which helps to prevent his or her internal organs from moving due to
gravity and contributes to a precise irradiation. If normal magnets are used for this
7 Concluding Remarks
7.2 Superconductor Technology in the Future
Superconductivity has significantly contributed to the progress in solid state physics
in the 20th century. As described in this book, superconductors are common materials and are classified as one of the fundamental magnetic materials in electromagnetism. These are typical materials that show irreversibility in magnetic hysteresis
from the viewpoint of thermodynamics. Some new physics may also be based on
superconductors. Thus, superconductors are attractive substances.
The property of superconductors that the resistivity is zero under static conditions
is not only interesting from the viewpoint of physics, but also attractive from that of
application. The area of application that the superconductor technology using zero
resistivity can cover is widely spread over various fields, including power applications, energy saving, the environment, transportation systems, industrial technology,
medicine, etc. In addition, it extends even to the field of electronics, using its inherent
nonlinear properties (see Fig. 7.1). Information technology was a part of electronics in
former times, although it deeply penetrates all fields of technology now, and research
and industry in each field can no longer exists without it. Even an important wide
area in people’s daily life, such as telecommunications, distribution, and medical
services, is supported by information technology. Superconductor technology is also
a similar but slightly different technology that supports society, and it is expected to
support even high-level information technology.
In this section the application of superconductor technology in the fields of medical
treatment, environment, transportation, and energy will be briefly introduced.
(1) Medical treatment
The application of superconductors to medical treatments is roughly classified into
two categories from the viewpoint of technology. One of them is the application of
flux pinning phenomena, which is similar to other applications in the fields of energy
and environment, and the other is the application of the Josephson effect, which has
not been introduced in this book.
The most widely used type of equipment in the first category comprises the
magnetic resonance imaging (MRI) systems mentioned in Chap. 1. Very strong and
stable magnetic fields can be produced by superconducting magnets operated in
persistent current mode, which makes it possible to visualize clear cross-sections
of human body using the nuclear magnetic resonance technique. Open-type MRI
systems that reduce the anxiety of subjects are likely to become popular in the near
future.
Another system using superconducting magnets is heavy ion therapy for cancer
treatment. This is similar to a technique used in particle physics, where heavy ions
accelerated by a strong magnetic field are used to directly irradiate tumor cells with
high precision. In particular, a rotating gantry can irradiate the tumor while directing
the beam from an arbitrary direction, and hence, the subject’s body can remain in a
fixed position, which helps to prevent his or her internal organs from moving due to
gravity and contributes to a precise irradiation. If normal magnets are used for this