Superconductors: Magnetic Field and National High Magnetic Essay

Submitted By jasguliani
Words: 816
Pages: 4

Advantages
Maglev train cars are less expensive to build and are relatively quiet in comparison to conventional trains.
The maglev tracks take up a lot less land, because they are elevated. This also reduces the amount of collisions and accidents.
No traffic!
Maglev trains use far less energy than other types of transportation.
Maglev trains do not pollute (since instead of using fossil fuels, magnetic fields are used to levitate and propel the trains forward).
Maglev trains are much faster, because they float over the track eliminating rolling resistance and potentially improving the power efficiency.
Maglev trains require Less maintenance (no wear because they float over the track).

A lot of potential. The possibility of linking 2 cities, over a distance of 1500km.
Disadvantages
Cost is major issue when considering maglev trains, especially since they cannot operate on the existing, conventional rails. Guideways would need to be built in order to make use of this new technology, costing approximately $8.5 billions.
The weight of the electromagnets in the EMS and EDS systems are also an issue. A very strong magnetic field is required to levitate the heavy trains, (the transrapid TRO7 weighs 45 tons) and maintaining the field constant requires a lot of energy which is expensive.
Magnets & Superconductors

Magnets
Magnets are metals that have both a north and a south pole. The like poles repel and the unlike poles attract.
Electromagnets
Electromagnets exhibit the same behavior as magnets but only when provided with an electric current (Brain, 2000). Therefore conventional magnets are often referred to as permanent magnets. Both permanent and electromagnets produce a magnetic field that exerts a force on everything around it.
Magnetic Force
Ohanian, Markert (2007) use the following equation for the magnetic force: F = qvB sin &alpha
F: magnetic force (in N) q: charge (in C) v: velocity (in m/s)
B: magnetic field (in T) α: angle between velocity and magnetic field.
Magnetic Field
Ohanian, Markert (2007) use the following equation for the magnetic field: B = μ0/4&pi I/r
B: magnetic field (in N) μ0: permeability constant = 4π x 10-7 N ⋅ m2 / C2 ≈ 1.26 x 10-6 N ⋅ m2 / C2
I: electrical current (in A) r: distance between particles (in m)
Magnetic Flux
Ohanian, Markert (2007) use the following equation for magnetic flux: ΦB = BA cos Θ
ΦB: Magnetic Flux (in Wb)
B: magnetic field (in T)
A: Area (in m2)
If you change the flux within a given area, the magnetic field will change (Ohanian, Makert 2007). This change results in the generation of a current (Ohanian, Makert 2007).
Superconductors
Certain electromagnets can be cooled or heated to a critical temperature (Tc) such that current passing through them encounters no resistance (National High Magnetic Field Laboratory). Therefore superconductors produce a much stronger magnetic field than an electromagnet that has not reached the required temperature (National High Magnetic Field Laboratory). Electromagnets that become superconductors at temperatures near absolute zero are classified as type 1 superconductors (National High Magnetic Field Laboratory). In constrast electromagnets that become superconductors when cooled with liquid nitrogen are considered type 2 superconductors (National High Magnetic Field Laboratory).Common superconducting metals include Mercury (Tc = 4.2 K), Yttrium-123 and Praseodymium-123 (National High Magnetic Field Laboratory).The main metal used for maglev superconductors is Yttrium Barium Copper Oxide (National High Magnetic Field Labratory).
The magnets in the maglev track are made of neodymium iron boride (National High Magnetic Field…