Abstract: A multiple resonance sample coil for a magic angle spinning nuclear magnetic resonance probe is comprised of a solenoid coil that resonates at low frequencies and a resonator that resonates at high frequencies. The ends of the low frequency solenoid coil are electrically connected to the high frequency resonator to eliminate arcing and allow the solenoid coil to extend the full width of the resonator. In some embodiments, the high frequency resonator is constructed from the outermost turns of the solenoid coil in the form of a birdcage resonator. In another embodiment, the solenoid coil is electrically connected to one turn of the resonator and the other turn is used as part of a trap to shunt the resonator at low frequencies.

Abstract: A four-ring birdcage coil having at least one moveable tuning ring for double resonance MRI includes low-pass configuration in both channels so that the HF mode only requires a small capacitance for resonance, enabling easy modification of a single resonance coil into a double resonance coil by incorporation of non-contact coupling rings whose capacitive coupling with the rungs generates enough capacitance to introduce the high-frequency resonance mode. The coil also includes at least one moving ring for broad range tuning in the HF channel. The LF channel is adjusted by a variable capacitor that is not directly connected to the coil, thus the frequency adjustment on each channel is independent. The HF channel is connected to the input cable by coupling capacitor. The LF channel is connected to the input cable by coupling inductor. This alternating driving scheme provides sufficient channel isolation and obviates the need for an external isolation network.

Abstract: A multiple resonance sample coil for a magic angle spinning nuclear magnetic resonance probe is comprised of a solenoid coil that resonates at low frequencies and a resonator that resonates at high frequencies. The ends of the low frequency solenoid coil are electrically connected to the high frequency resonator to eliminate arcing and allow the solenoid coil to extend the full width of the resonator. In some embodiments, the high frequency resonator is constructed from the outermost turns of the solenoid coil in the form of a birdcage resonator. In another embodiment, the solenoid coil is electrically connected to one turn of the resonator and the other turn is used as part of a trap to shunt the resonator at low frequencies.