APPLICATIONS OF

SUPERCONDUCTIVITY

1) Low temperature liquid helium superconductors have been used to fabricate high field magnets and some electronic and radio frequency devices.

Superconducting Magnets We know that an electric current in a

wire creates a magnetic field around the wire. The strength of the magnetic field increases as the current in the wire increases. Since SCs can carry large currents without energy loss, they are well suited for making strong magnets

7 T horizontal bore superconducting magnet

AMS-02: With a diameter of nearly 3 m and a cold mass approaching 2 tonnes, AMS-02 will be the first large superconducting magnet to be launched into space.  The 14 coils generate fields up to 7 T and are indirectly cooled to 1.8 K by 2500 liters of superfluid helium.

For more details please visit: http://en.wikipedia.org/wiki/Superconducting_magnet

Electronic & Radio Frequency Devices

 In electronics industry, ultra-high-performance filters are now being built. Since superconducting wire has near zero resistance, even at high frequencies, many more filter stages can be employed to achieve a desired frequency response. This translates into an ability to pass desired frequencies and block undesirable frequencies in high-congestion radio frequency applications such as cellular telephone systems.

2) The superconducting magnets have been employed in NMR spectrometers and NMR imaging is used in medical diagnostics.

Nuclear Magnetic Resonance (NMR) Spectrometers

NMR spectrometer technology uses superconducting wires cooled with cryogens (liquid helium & liquid nitrogen) to generate a magnetic field. NMR spectrometers provide the most homogenous magnetic fields and the greatest spectral resolution. NMR spectroscopy can be used for chemical analysis, reaction monitoring, and quality assurance/quality control experiments. Higher-field instruments enable unparalleled resolution for structure determination, particularly for complex molecules.

Nuclear Magnetic Resonance Imaging (NMRI) On applying a strong superconductor

derived magnetic field into the body, hydrogen atoms that exist in the body's water and fat molecules are forced to accept energy from the magnetic field. They then release this energy at a frequency that can be detected and displayed graphically by a computer.

An Nuclear Magnetic Resonance Imaging (NMRI) Scanner.(Simply called as MRI Scanner)

3) Superconductors are used for effective magnetic shielding.

Magnetic Shield When you place a superconductor near

a magnet, the magnetic field gets repelled by the superconductor because it does not allow the field to penetrate its surface (Meissner Effect).

Normal Conductor Superconductor

4) Superconductors are used as magnetic energy storage.

Superconducting Magnetic Energy Storage (SMES) SMES systems store energy in the magnetic field

created by the flow of direct current in a superconducting coil.

Once the superconducting coil is charged, the current will not decay and the magnetic energy can be stored indefinitely.

The stored energy can be released back to the network by discharging the coil.

SMES loses the least amount of electricity in the energy storage process compared to other methods of storing energy. i.e. the SMES systems are highly efficient; the round-trip efficiency is greater than 95%.

The world’s largest superconducting magnetic energy storage system: This system counters sudden drops in voltage (line-drops) that result from lightning strikes and other natural phenomena. The 10,000-kW superconducting magnetic energy storage system installed at the Kameyama (a City in Japan) Plant can generate high voltage in an instant and counter the effects of line-drops.

5) Superconductors have been used to produce various devices based on superconducting quantum effects such as SQUIDS and Josephson devices

Superconducting Quantum Interference Device (SQUID) A SQUID is a very sensitive

magnetometer used to measure extreme low magnetic fields.

SQUIDs are sensitive enough to measure fields as low as 5×10−18 T (i.e. can detect a change of energy as much as 100 billion times weaker than the electromagnetic energy that moves a compass needle,  such as subtle changes in the human body's electromagnetic energy field)

The inner workings of an early SQUID

Josephson Devices In 1962 Brian D. Josephson predicted that

electrical current would flow between two superconducting materials, even when they are separated by a non-superconductor or insulator. His prediction was later confirmed and won him a share of the 1973 Nobel Prize in Physics. This tunneling phenomenon is today known as the "Josephson effect“

SQUIDs work based on the Josephson effect. Devices that work based on the principle of Josephson effect are called Josephson Devices.

6) For high speed magnetic trains and ship drive system superconductors are used.

MagLev Trains The Maglev (derived from Magnetic

Levitation) train system works by utilizing magnetized coils running along a track that attract and repel large superconducting magnets in the train’s undercarriage and allow it to levitate almost 4 inches off the ground. Power supplied to the coils in the guideway then creates polarizing forces that pull and push the train along. As the only resistance is air,

Working of Maglev Trains The maglev train is equipped with several

superconductors, while a series of electromagnetic coils run along the length of the track. When the train approaches these coils, the superconductors induce a current in them that works to both levitate the train several centimeters above the track and to center it between the guide rails.

A moving magnetic field can hence produce inducted currents that, in reaction, will produce a second magnetic field interacting with the first one. It is this force that lifts the Maglev.

Maglev propulsion along a track that attract and repel large superconducting magnets

Advantages of using Superconductors in Maglev Trains

Conventional electromagnets waste much of the electrical energy as heat, they would have to be physically much larger than superconducting magnets.

The beauty of maglevs is that they travel on air. The consequent elimination of friction means much greater efficiency: high speed (>500kmph) and less wear and tear (i.e. less maintenance). Just as electrons move more efficiently through a superconducting wire because there is no resistance, so, too, does a maglev travel more efficiently than a regular train because there is no friction between the wheels and the track, thanks to the Meissner Effect.

JR–Maglev, or SCMaglev (Super-Conducting Maglev) – Japan Railways

A maglev train is coming out of the Pudong International Airport, China

7) Superconductors are used in computers and information processing.

Computing and Information Processing Superconductivity could even be used to build

a quantum computer, enabling massively parallel processing (to reach speed at the rates of 100 GHz)

Quantum computers are different from digital computers based on transistors. Whereas digital computers require data to be encoded into binary digits (bits), quantum computation uses quantum properties to represent data and perform operations on these data.

Quantum Processors make use of superconducting qubit (Quantum Bits) architecture.

THE END

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