In order to increase the magnetic resonance (MR) signal induction efficiency within the coil, quadrature coils are constructed with extra loops and circuits. When compared to coils of the same size, this design innovation helps to boost the signal-to-noise ratio (SNR) by about 40%.
Naturally ferromagnetic materials have a high magnetic permeability and a long half-life of magnetization, which makes them suitable for use as permanent magnets. By matching the magnetic domains within ferromagnetic materials, a high magnetic field is applied to the material to produce these magnets. Permanent magnets don't require an external power source to create their own magnetic field once they are magnetized. They are frequently utilized in many different applications, including speakers, generators, and motors.
One kind of superconducting magnet that is frequently utilized in many different applications is the solenoid. Its central axis is encircled by wire coils in a cylindrical form. A solenoid usually generates a homogeneous magnetic field that is parallel to the cylinder's axis. The term "solenoid horizontal" in the provided response denotes that the cylinder's axis is aligned horizontally and that the solenoid is oriented in a horizontal direction. As a result, a horizontal magnetic field will be produced by the solenoid.
The process of aligning wires side by side results in a solenoid magnet. A solenoid is an electric current-carrying coil of wire that produces a magnetic field as the current passes through it. The magnetic field created by the wires arranged side by side is more powerful and consistent. For this reason, in this instance, a solenoid magnet is the appropriate solution.
When subjected to an external magnetic field, materials classified as paramagnetic exhibit a modest rise in their magnetic field. Their atomic or molecular magnetic moments line up with the applied field, which is the cause of this. Their magnetic response is modest and parallel to the applied field due to their low and positive susceptibility.
According to the provided information, the magnet has strengths of up to 0.3 T, may be switched off, and can be used in both horizontal and vertical field systems. The word "resistive" implies that this kind of magnet works with materials that have the ability to regulate the strength of the magnetic field and switch it off when necessary. Based on the information given, "Resistive" is the appropriate response.
The use of metal, usually steel, in a scan room's walls to contain the fringe field produced by a magnetic source is known as passive magnetic shielding. The magnetic field can be contained by this kind of shielding without the need for active control devices or external power. The magnetic field lines are instead redirected and absorbed by the metal's natural qualities, keeping them from leaving the scan room and interfering with surrounding objects or people.
Using additional magnets and their magnetic fields to contain or lessen the magnetic field of the primary magnet is known as "active magnetic shielding." By creating opposing magnetic fields to cancel out or constrain the field of the primary magnet, this approach actively manipulates the magnetic field. This is not the case with passive magnetic shielding, which absorbs and reroutes the magnetic field through the use of high-permeability materials. As a result, the selected right response of "active" is consistent with the justification supplied.
Because superconducting magnets use direct current supplied to a coil of wire cooled by immersion in liquid helium or cryogen, the provided correct answer is "Superconducting." The wires' temperature is lowered by this cooling process, which enables superconductivity—the property of conducting electricity with zero resistance—in the wires.
Positive susceptibility, or the attraction to a magnetic field, is a characteristic of ferromagnetic materials. Furthermore, even after the external magnetic field is eliminated, they can still be magnetized. The material's magnetic moments aligning to produce a strong magnetic field is what causes this behavior. As a result, the statement provided appropriately characterizes ferromagnetic materials.
Positive susceptibility to a magnetic field is exhibited by superparamagnetic materials. They are not as strong as ferromagnetic materials, but they are still stronger than paramagnetic materials. Superparamagnetic materials can improve the visibility of specific tissues or structures in magnetic resonance imaging (MRI) because they are frequently utilized as T2 contrast agents.
