Magnet Flashcards
3principles types of magnet
Natural -Eartth
Permanent -artificially produced by changing in the field
Electromagnets- wrapped around
3 interaction of matter with magnet
Diamagnetic, Ferromagnetic, paramagnetic
Unaffected
Diamagnetic
Strongly attracted
Alnico an alloy of aluminum, nikel and cobalt
Ferromagnetic
Slightly attracted
Paramagnetic
The earth’s magnetic field at the equator is
50uT
The earth’s magnetic field at the poles is
100uT
Typically coil of wire through which a magnetic field is induced
Resistive magnet
Most commonly used in magnet
Permanent magnet
Alnico alloy that is used to make permanent magnet
Permanent magnet
Special coiling agent called and use produce low temperature (4k)
Liquid cryogen
Electromagnetic coils are placed in insulated chamber
Dewar or cryostat (contains helium)
The process of bringing the superconducting magnet to the temperature is called?
Ramping
Refers to magnet sudden loss
QUENCHING
High insulated bottle
Dewar
2chamber of dewar
Outer chamber and inner chamber
Contain liquid nitrogen
Outer chamber
Contain liquid helium
Inner chamber
Quenching the process where by there is a sudden loss absolute 0of temperature
Result of helium escaping
Superconductor magnet
2 Mri spin
Angular momentum rotation, magnet moment
Portion of the magnetic field extending away
Fringe feild
Length of the pulse determine the amount of energy given to the nuclie
Radio frequency pulse
Single proton gives a
Large magnet moment
7 Types of element that away MR active
Hydrogen, carbon, nitrogen, oxygen, fluorine, sodium, phosphorus
Hydrogen
1
carbon
13
nitrogen
15
oxygen
17
fluorine
19
sodium
23
phosphorus
31
