Increases in performance of superconducting materials, such as higher operating temperatures, stronger magnetic fields, and higher current densities, are enabling new applications of superconductivity. Examples include smaller and cheaper magnets for magnetic resonance imaging (MRI), more efficient transmission of electricity, faster electronic devices and quantum computers, and magnetic levitation trains. However, challenges remain in achieving room temperature superconductivity and further improvements in materials needed for some applications like fusion power.
1. A/Prof Jeffrey Funk
Division of Engineering and Technology Management
National University of Singapore
For information on other technologies, see http://www.slideshare.net/Funk98/presentations
2. Source: PhysicaC: Superconductivity Volume 484, 15 January 2013, Pages 1–5
Proceedings of the 24th International Symposium on Superconductivity (ISS2011)
How are these improvements changing the economics of superconductivity?
in-plane grain alignment enabled higher current densities; achieved with
ion beam assisted deposition, rolling-assisted biaxiallytextured substrates
4. Bit Energy = power consumed per clock period x number of active devices
RSFQ: rapid single flux quantum, relies on quantum effects in
superconducting devices
Source: superconductivity web21, January 16, 2012. www.istec.or.jp/web21/pdf/12_Winter/E15.pdf
How are these improvements changing the economics
of superconductivity for electronic applications?
5. How are these improvements changing the economics of quantum computers?
Source: Science, Vol339, 8 March 2013, pp. 1169-1174
7. Session
Technology
1
Objectives and overview of course
2
When do new technologies become economically feasible?
3
Two types of improvements: 1) Creating materials that better exploit physical phenomena;2) Geometrical scaling
4
Semiconductors, ICs, electronic systems, big data analytics
5
MEMS and Bio-electronics
6
Lighting, Lasers, and Displays
7
Information Technology and Land Transportation
8
Human-Computer Interfaces, Biometrics
9
Superconductivityand Solar Cells
10
Nanotechnology and DNA sequencing
This is Ninth Session of MT5009
8. Characteristics of superconducting materials
◦zero electrical resistance
◦expulsion of magnetic fields
Most superconducting materials do so at very low temperatures (-250C) and thus phenomenon was not useful until the last few decades
Challenges: existing materials
◦only super-conduct at low temperatures (-100C)
◦do not carry sufficient magnetic fields or currents
◦are expensive
9. Evidence of High Magnetic Fields
http://www.youtube.com/watch?v=YrdbNLT-9Cc(1:00 –1:30
http://www.youtube.com/watch?v=lCZVPROkB8E(zero –1:30)
http://www.cnn.com/2014/08/29/tech/innovation/can- levitating-appliances-take-off/index.html
10. Creating materials (and their associated processes) that better exploit physical phenomenon
Geometrical scaling
◦Increases in scale
◦Reductions in scale
Some technologies directly experience improvements while others indirectly experience them through improvements in “components”
A summary of these ideas can be found in
1)California Management Review, What Drives Exponential Improvements? Spring 2013
2)book from Stanford University Press, Technology Change and the Rise of New Industries, 2013
11. Creating materials (and their associated processes) that better exploit physical phenomena; finding/creating materials that
◦superconductat higher temperatures
◦enable high magnetic fields
◦carry high currents (i.e., critical current)
◦are easy to fabricate
Geometrical scaling
◦To what extent will increases in the scale of production equipment lead to lower costs?
Some technologies directly experience improvements while others indirectly experience them through improvements in “components”
◦Better superconducting materials may lead to better MRI, electricity distribution, computers, maglev, fusion
12. Increases in performance (temperature, magnetic fields, current densities)
Examples of large or potentially large applications
◦Magnetic Resonance Imaging (MRI)
◦Energy Distribution and Transmission
◦Electronic devices and computing
◦Magnetic levitating trains
◦Fusion
Room temperature superconductors?
Conclusions
14. Another Look at Increases in temperature…
http://www.ccas-web.org/superconductivity/
15. Organic Superconductivity, Denis Jerome, Chapter 5, in Superconductivity in New Materials, ed. by Z. Fisk and H. R. Ott(Elsevier, 2010)
Log Plot of Increases in Maximum Temperature at which…..
16. But maximum magnetic fields and currents are also important
Too high of magnetic fields or currents cause superconducting phenomenon to end, i.e., resistance to dramatically increase
How have maximum magnetic fields and currents been improved?
◦It’s actually quite controversial
23. Increases in performance (temperature, magnetic fields, current densities)
Examples of large or potentially large applications
◦Magnetic Resonance Imaging (MRI)
◦Energy Distribution and Transmission
◦Electronic devices and computing
◦Magnetic levitating trains
◦Fusion
Room temperature superconductors?
Conclusions
25. The Major Cost of Magnetic Resonance Imaging is the Magnets
26. Can be smaller and thus cheaper than conventional magnets
◦Also less energy loss
Most are composed of niobium-titanium
◦critical temperature of 10 Kelvin
◦can Superconductup to about 15 Tesla
More expensive magnets can be made of niobium-tin (Nb3Sn)
◦Critical Temperature of 18 K
◦When operating at 4.2 K, can maintain magnetic field intensity up to 25 to 30 Tesla
◦Unfortunately, difficult to make filaments from them
Vanadium-gallium is another material used for the high field inserts
Source: Wikipedia entry on superconducting magnet
27. Increases in performance (temperature, magnetic fields, current densities)
Examples of large or potentially large applications
◦Magnetic Resonance Imaging (MRI)
◦Energy Distribution and Transmission
◦Electronic devices and computing
◦Magnetic levitating trains
◦Fusion
Room temperature superconductors?
Conclusions
28. Can be used in transmission cables or in windings for motors, generators, transformers
Have lower energy losses than do conventional materials such as copper
Do not require cooling oils, which have risk of fire
29. Enable smaller and thus potentially cheaper generation, distribution, transmission of energy
◦Higher current densities in generator and motor windings and in transmission lines
◦Higher frequency and thus more compact transformers
◦Ideal for high population densities (some installed in NYC)
http://www.youtube.com/watch?v=gBtQvaLKzA0
http://www.youtube.com/watch?v=2QuU9-jBo3U
http://www.youtube.com/watch?v=a06TNIgbFnk
31. Source: PhysicaC: Superconductivity Volume 484, 15 January 2013, Pages 1–5
Proceedings of the 24th International Symposium on Superconductivity (ISS2011)
Improvements in BSCCO and YBCO superconducting wires/tapes
in-plane grain alignment enabled higher current densities; achieved with
ion beam assisted deposition, rolling-assisted biaxiallytextured substrates
32. Growth of thick YBzCuOlayers via a barium Fluoride process, superconducting science and Technology, vol26, no. 1
Improvements in Current
of YBCO tapes
Making them thicker
without reducing current
density
Through better processes
33. Source: CIGRÉ SC D1 WG38 Workshop on High Temperature Superconductors (HTS) for Utility Applications
Beijing, China, 26 April 2013 Improvements in Price
Price of copper was 15-25$/kA-meter
Do reductions in size justify the increases in price?
34. Source: 'CAST Report : The Future of Superconducting Applications' Jan. 31. 2011
Power capacity is 100 MWA for conventional transformerWhat About Transformers? Increases in size of them
35. 35
•Amount of energy stored is function of Current Squared
E = ½ LI2
•Thus, increases in current can lead to very large increases in energy storage density
•Very fast discharge rates since no electrical resistanceGood News
•Current price is $50,000/kWh
•100 times the price of energy storage with lead acid batteries ($30/kWh)
•100 times lower price is needed, which could come from 10 times increase in current densitiesBad News
Source: Renewable Energy Technologies, Jean-Claude Sabonnadi, http://www.scribd.com/doc/148085576/Renewable-Energy-Technologies
37. Can we charge vehicles while they move on highways?
Wireless charging is getting cheaper through advances in power electronics
◦Cheaper MOSFETs reduce cost of wireless charging and frequent recharging reduces necessary size of batteries
◦Qualcomm and other firms offer systems
Vehicles are also getting lighter through use of electronic controls, which are also enabled through improvements in power electronics
◦Reduces necessary size of batteries
Can superconducting cables help us move to wireless charging on highways?
38. Increases in performance (temperature, magnetic fields, current densities)
Examples of large or potentially large applications
◦Magnetic Resonance Imaging (MRI)
◦Energy Distribution and Transmission
◦Electronic devices and computing
◦Magnetic levitating trains
◦Fusion
Room temperature superconductors?
Conclusions
39. Placing a thin insulating barrier between two superconductors constitutes a Josephson junction
Josephson effect is form of quantum tunneling but with superconducting Cooper Pairs, instead of electrons
Josephson junctions can be implemented in rapid single flux quantum (RSFQ) chips
◦digital information is carried by magnetic flux quanta instead of by voltages and currents
◦Advantages are faster speeds and much lower energy consumption
41. Bit Energy = power consumed per clock period x number of active devices
RSFQ: rapid single flux quantum, relies on quantum effects in
superconducting devices
Source: superconductivity web21, January 16, 2012. www.istec.or.jp/web21/pdf/12_Winter/E15.pdf
Improvements in Power Consumption and Speed
42. Unlike conventional computers, each “Qbit” can be both in 0 or 1 according to a probability distribution
Thus, Qubitscan hold more information than can conventional bits and this advantage increases as number of Qubitsincrease
This “superposition” also means quantum computers can perform many calculations simultaneously
Qubitsrepresent atoms, ions, photons or electrons that act together as computer memory and processor
◦But superconducting Josephson Junctions may be best approach
One major challenge: quantum system needs to hold one bit of quantum information long enough for it to be written, manipulated, and read
http://www.youtube.com/watch?v=m3TOWanwuO8
43. Improvements in QbitLifetime and Number of Bits Per QbitLifetime
Source: Science, Vol339, 8 March 2013, pp. 1169-1174
44. Photograph of a chip constructed by D-Wave Systems Inc., mounted and wire-bonded in a sample holder. The D-Wave processor is designed to use 128superconductinglogic elements that exhibit controllable and tunable coupling to perform operations.
Source: https://en.wikipedia.org/wiki/Quantum_computer
45. Developed quantum computers that use “adiabatic quantum computing” to solve certain types of optimization problems
Comparisons show faster computation times with D-Wave’s computer than with conventional computers
Good at solving complex optimization problems that are difficult for conventional computers
◦shipping logistics, flight scheduling
◦search optimization (Google bought one in May 2013)
◦DNA analysis and encryption
Nature, Vol498, 20 June 2013, pp. 286-288
48. In tests last September, an independent researcher found that for some types of problems the D-Wave quantum computer was 3,600 times fasterthan a traditional Intel Quadcoreworkstation (2.4 Ghzquadcorechips with 16 GB of memory and about 420 GFlops)
According to a D-Wave official, the machine performed even better in Google’s tests, which involved 500 variables with different constraints. “The tougher, more complex ones had better performance,” said Colin Williams, D-Wave’s director of business development. “For most problems, it was 11,000 times faster, but in the more difficult 50 percent, it was 33,000 times faster. In the top 25 percent, it was 50,000 times faster.
http://nextbigfuture.com/2013/05/dwave-512- qubit-quantum-computer-faster.html
49. Quantum or not, controversial computer yields no speedup: Conventional computer ties D-Wave machine
Science 20 June 2014, Vol344, Issue 6190
D-Wave says the test was not complex enough to demonstrate Quantum Computer advantages
50. Increases in performance (temperature, magnetic fields, current densities)
Examples of large or potentially large applications
◦Magnetic Resonance Imaging (MRI)
◦Energy Distribution and Transmission
◦Electronic devices and computing
◦Magnetic levitating trains
◦Fusion
Room temperature superconductors?
Conclusions
52. Requirements for superconducting materials
◦Current density greater than 105 A/cm2
◦Magnetic field greater than 1 T at 77K
◦Long wire lengths (> 100 m) so that windings need not be formed in multiple sections
◦Strength can withstand Lorentz forces and forces due to thermal expansion
◦Robustness to AC losses, wire uniformity, and quenching
◦Ductile Wire that can withstand bending during the coil winding process
First two OK, last three not OK?
Source: Mark Thompson, PhD Thesis, MIT, http://www.thompsonrd.com/Research/chapter1.htm
53. Have announced they will build 286 km maglev train line between Tokyo and Nagoya
◦Service start scheduled for 2027
◦581 km per hour, faster than existing 320 km/hour
◦Reduces travel time from 100 to 40 minutes
Cost is $100 billion or $300 Million per km
◦partly due to high cost of tunnels
◦86% of distance is tunnels
Typical cost of conventional railway is $20 Million per km
Japanese are trying to convince the U.S. to build a line between NY and Washington DC
http://edition.cnn.com/2013/12/08/business/japan-on-the-road-maglev/index.html?hpt=wo_bn1
http://www.youtube.com/watch?v=ltqp4McM2wY (from 2 minutes)
54. Increases in performance (temperature, magnetic fields, current densities)
Examples of large or potentially large applications
◦Magnetic Resonance Imaging (MRI)
◦Energy Distribution and Transmission
◦Electronic devices and computing
◦Magnetic levitating trains
◦Fusion–uses superconducting magnetics to “confine” the sun
Room temperature superconductors?
Conclusions
56. But stronger magnetic fields and thus better superconducting
magnets increase the economic feasibility of fusion
Source: http://www.plasma.inpe.br/LAP_Portal/
LAP_Site/Text/Tokamaks.htm
Fusion is Further in the Future
57. Increases in performance (temperature, magnetic fields, current densities)
Examples of large or potentially large applications
◦Magnetic Resonance Imaging (MRI)
◦Fusion
◦Magnetic levitating trains
◦Electronic devices
◦Other energy, including energy transmission
Room Temperature Superconductors?
Conclusions
58. UPDATE:Announcement of room temperature superconductors from highly compressed silicon and hydrogen was premature in journal Science by Saskatchewan, Canada and German researchers. The transition temperature was low for the data that they had but they believe there is pressure zone that performs better
59. In October of 2007, superconductivity near 175K was detected at ambient pressure in an Sn-In-Tm intergrowth. By doping roughly 28% of the Snatomic sites of that molecule with Pb, Tcis increased further to 181K (183K magnetic). The revised chemical formula thus becomes (Sn1.0Pb0.4In0.6)Ba4Tm5Cu7O20+ with a 1245/1212 (non-stoichiometric) structure
Source: http://superconductors.org/175K_pat.htm
61. Cost and performance of superconductivity continues to improve
How many further improvements are likely to be made from
◦Creating materials that better exploit the phenomena of superconductivity in terms of higher temperatures, currents, and magnetic fields?
◦Creating processes that enable the production, including low-cost production of these materials?
◦Increasing the scale of the production equipment?
62. What do these improvements mean for new applications?
◦Computing? Energy transmission?
◦Magnetic Levitating Trains? Fusion?
As improvements in superconductors occur, when will these new applications become possible and at what rate might they diffuse?
What kind of analyses can help us understand these issues
What kinds of opportunities will emerge for firms?
65. To gain some insight consider a breakdown by major components of both HTSC and LTSC coils corresponding to three typical stored energy levels, 2, 20 and 200 MW·h. The conductor cost dominates the three costs for all HTSC cases and is particularly important at small sizes. The principal reason lies in the comparative current density of LTSC and HTSC materials. The critical current (Jc) of HTSC wire is lower than LTSC wire generally in the operating magnetic field, about 5 to 10teslas(T). Assume the wire costs are the same by weight. Because HTSC wire has lower (Jc) value than LTSC wire, it will take much more wire to create the same inductance. Therefore, the cost of wire is much higher than LTSC wire. Also, as the SMES size goes up from 2 to 20 to 200MW·h, the LTSC conductor cost also goes up about a factor of 10 at each step. The HTSC conductor cost rises a little slower but is still by far the costliest item.