Maarg Manthan · Topic 8.10

Applications of Superconductors

Science & Technology › Physics – Mechanics, Waves and Thermodynamics · Topic 8.10

Superconductors are used where very strong magnetic fields, lossless current or extremely sensitive detection is needed. The largest use is in superconducting magnets, made from niobium-titanium or niobium-tin wire, which power magnetic resonance imaging machines in hospitals, particle accelerators such as the Large Hadron Collider and the magnets that confine hot plasma in fusion devices. Other uses include magnetically levitated trains, power cables and fault current limiters that cut losses in the grid, sensitive magnetometers called SQUIDs, and superconducting circuits that act as qubits in quantum computers. The main limits are the cost of cooling, the brittleness of ceramic materials and the difficulty of making long wires. India has superconducting research in fusion and in the National Quantum Mission.

5 min read · UPSC Prelims · Science & Technology · Physics – Mechanics, Waves and Thermodynamics

At a Glance

Medical MRI magnets
Transport Maglev trains
Energy Fusion magnets, power cables
Sensors SQUID magnetometers
Computing Superconducting qubits
Exam link UPSC Prelims, Science & Technology: Physics – Mechanics, Waves and Thermodynamics

Where Does It Fit?

This is the tenth topic of the macro on physics. It applies the properties described in the previous topic, linking physics to medicine, transport, energy and quantum technology. Previous topic: Superconductivity: History, Classification and Properties. Next topic: Types and Applications of Lasers.

Where Are Superconductors Used?

Application	How superconductors help
MRI scanners	Niobium-titanium coils cooled with liquid helium make the strong steady field of 1.5 to 3 tesla needed for detailed images, as in Imaging Methods: CT Scan, MRI, PET Scan
Particle accelerators	The Large Hadron Collider has superconducting dipole magnets cooled to about 1.9 kelvin, to bend high-energy proton beams around a 27-kilometre ring
Fusion reactors	Tokamaks use superconducting magnets to confine plasma. The ITER project, in which India is a partner, uses large magnets, and India’s SST-1 at the Institute for Plasma Research in Gandhinagar is a superconducting tokamak
Maglev trains	Superconducting magnets lift and push the train without contact. A Japanese test train reached 603 kilometres an hour in 2015
Power transmission	Superconducting cables carry large currents with no resistance loss, and fault current limiters protect the grid
Motors and generators	Lighter and more efficient machines for ships, wind turbines and aircraft research

Which Sensors and Quantum Devices Use Superconductivity?

SQUIDs: superconducting quantum interference devices detect extremely weak magnetic fields, used in magnetoencephalography to map brain activity, in geology and in materials testing.
Josephson junctions: tunnelling devices used as voltage standards and as fast switches.
Superconducting qubits: circuits of superconductors cooled close to absolute zero behave as quantum bits, used by several quantum computer builders.
Single photon detectors: superconducting nanowires detect individual photons for quantum communication and astronomy.
Energy storage: superconducting magnetic energy storage holds energy in a magnetic field of a coil, ready for a quick release.
Space and defence: sensitive detectors for telescopes and for detecting submarines are research uses.

What Else Should You Remember?

Cooling cost: the need for liquid helium or nitrogen adds expense, and helium is a limited resource.
High-temperature materials: ceramic superconductors are brittle and hard to make into wire, although second-generation tapes of yttrium barium copper oxide are being produced, as in Superconductivity: History, Classification and Properties.
National Quantum Mission: approved by the Union Cabinet in April 2023 with an outlay of about Rs 6,000 crore for 2023 to 2031, it supports quantum computing, communication, sensing and materials, including superconducting qubit research in India.
Indian MRI capacity: India imports most superconducting MRI magnets, so indigenous development is a goal, according to health technology plans.
Fusion power: ITER in France aims to show that fusion can produce more energy than it uses, and India has supplied large components such as the cryostat, as reported.
Environmental benefit: lossless cables and efficient machines would cut energy waste and emissions.
Safety: a sudden loss of superconductivity, called a quench, releases heat in magnets, so systems have protection circuits.
Exam pattern: uses of superconductors, the principle of maglev trains and quantum computing links.
Superconducting magnets in industry: superconducting magnets are used for separating minerals and in research on materials, where very strong fields are needed over large volumes.
Electric power: superconducting wind turbine generators and cables are being tested for compact and efficient power, though costs remain high.
Quantum sensing: superconducting sensors support navigation without satellites and detection of tiny signals in physics experiments.
Environmental angle: cutting energy losses in transmission can lower fuel burnt in power stations and reduce emissions.
Superconducting wires: commercial wires are made as fine filaments of niobium-titanium in a copper matrix, which carries the current if superconductivity is lost for a moment.
Medical research: very strong superconducting magnets of 7 tesla and above are used in research scanners for finer images of the brain.

Why Does It Matter for the Exam?

Application questions: which technology uses superconducting magnets.
Science policy link: National Quantum Mission and participation in ITER.
Current affairs link: quantum computers, fusion records and maglev projects.
Health link: MRI availability and cost.
Common errors: thinking that maglev trains use ordinary electromagnets only, or that all superconductors work without cooling.

As an analytical point, superconductors already shape medicine and big science. Their wider use in power and transport depends on cheaper materials and cooling.

Why Is This Topic Important?

Facts Uses and projects asked
Policy Quantum Mission, ITER
Limit Cooling cost

What Came Next?

The next topic covers the types and applications of lasers. Next topic: Types and Applications of Lasers.

Key People and Terms

SQUID Superconducting quantum interference device
Qubit Quantum bit
Tokamak Doughnut-shaped fusion device
Maglev Magnetic levitation train
Quench Sudden loss of superconductivity
Cryostat Cold container

Exam Corner

Points to Remember

MRI uses superconducting magnets.
LHC magnets at about 1.9 K.
SST-1: India’s superconducting tokamak.
National Quantum Mission: 2023.
SQUID detects tiny magnetic fields.

Do Not Confuse With

Maglev and ordinary train Floating on magnets versus wheels on rails
Fusion and fission Joining versus splitting nuclei
Qubit and bit Quantum versus classical unit

Memory Hook

MRI, LHC, tokamak ring: superconducting magnets; maglev floats, SQUID senses, qubit computes, the cooling is the thing.

Mains Angle

Questions ask about technologies that depend on superconductors. These points add depth.

Medicine MRI
Energy Fusion and cables
Quantum Qubits

A Question You May Face

An original practice question, not a past paper question.

“Discuss the applications of superconductors in medicine, energy, transport and quantum technology, and the factors limiting their wider use.”

How to Answer

Magnets MRI, LHC.
Energy Fusion, cables.
Quantum Qubits.
Limits Cooling.

GS Relevance

Prelims: uses of superconductors, MRI, maglev, SQUID, quantum computers, ITER. GS Paper 3: science and technology, energy.

Frequently Asked Questions

What are the main applications of superconductors?

The main applications are strong superconducting magnets for MRI machines, particle accelerators and fusion devices, maglev trains, lossless power cables and fault current limiters, extremely sensitive magnetometers called SQUIDs, and superconducting circuits used as qubits in quantum computers. Cooling is the main practical limit.

How does a maglev train use superconductors?

A maglev train uses powerful superconducting magnets to levitate above a guideway and to propel it forward without friction between wheels and rails. Because there is no contact, the train can reach very high speeds, and a Japanese test train reached 603 kilometres an hour in 2015, though the system is costly.

Why are superconducting magnets used in MRI machines?

MRI needs a very strong, steady and uniform magnetic field, typically 1.5 to 3 tesla, which superconducting coils can provide without continuous power loss once the current is set. The coils of niobium-titanium are kept cold with liquid helium, which makes the machines expensive to build and run.

What is a SQUID?

A SQUID, or superconducting quantum interference device, is an extremely sensitive detector of magnetic fields, built from superconducting loops with Josephson junctions. It can detect fields billions of times weaker than the Earth's field, so it is used to map brain activity, in geological surveys and in testing materials.

What role does India play in superconductor-based fusion research?

India is a partner in the ITER fusion project in France, where superconducting magnets confine the plasma, and has supplied components such as the cryostat. India also runs its own superconducting tokamak, SST-1, at the Institute for Plasma Research in Gandhinagar, which is used to study plasma confinement.

PYQ Practice — Statement Analysis

1 MRI machines use superconducting magnets.

True

Cooled with liquid helium.

2 SST-1 is a superconducting tokamak in Gandhinagar.

True

At the Institute for Plasma Research.

3 Superconducting qubits need no cooling.

False

They work near absolute zero.

4 Maglev trains run on conventional rails and wheels.