this is 2nd year course. also, please include all the steps and explanations ple
ID: 1808275 • Letter: T
Question
this is 2nd year course. also, please include all the steps and explanations please. thanks!
In magnetic resonance imaging (MRI), we use radiofrequency (RF) coils to transmit oscillating magnetic fields into the patient. The coils are essentially series RLC antennas and must be tuned to resonate at the characteristic frequency of the experiment (called the Larmor frequency) for efficient transmission. This frequency changes as a function of the field strength of the MRI machine. At 1.5 Tesla field strength, it is 64 MHz and at 3.0 Tesla, it is 128 MHz. A simple RF coil is a loop of wire (which provides the inductance) broken by capacitors in series. (3 Marks) If the value of each of the four capacitors is 20 pF for a coil tuned to operate in a 1.5 Tesla MRI, what is the inductance of the coil? (2 Marks) If you w anted to use the same coil at 3.0 Tesla, what new value would you need to use for the capacitors?Explanation / Answer
(a)For 1.5 T, Fc=64 MHz=1/(LC)
Here C is in series. So Cnet=20/4=5pF
L=1/(64*64*5*10^-12)=0.488H
(b)L remaining same, Fc changes to 127MHz as the Field Strngth changd to 3T
128=1/((0.488x10-6(*(C))
Cnet=125pF
Capacitance of indivisual capacitor=125x4=500pF
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.