NMR transfer standard
A device for simulating a sample of gas having a specific level of polarization when measured by a NMR pickup coil includes an active circuit loosely coupled to the NMR pickup coil. The active circuit responds as a hyperpolarized gas having the specific level of polarization when measured by the NMR pickup coil.
1. A device for simulating a sample of gas having a specific level of polarization when measured by an instrument including an NMR pickup coil, said device comprising:
an active circuit coupled to the NMR pickup coil, wherein said active circuit responds as a hyperpolarized gas having the specific level of polarization when measured by the NMR pickup coil.
2. The device of claim 1 , wherein said active circuit is loosely coupled to the NMR pickup coil.
3. The device of claim 2 , wherein said active circuit includes a transfer standard coil.
4. The device of claim 3 , wherein said active circuit includes a power supply.
5. The device of claim 4 , wherein said power supply is provided by batteries coupled to the active circuit.
6. The device of claim 5 , wherein said active circuit further comprises a high-Q oscillator circuit.
7. The device of claim 6 , wherein said oscillator circuit is an LRC circuit.
8. The device of claim 7 , wherein said oscillator circuit is a Wien-bridge circuit.
9. The device of claim 8 , wherein said active circuit has a Q level of approximately 1500 at 24 kHz.
10. The device of claim 1 , wherein said active circuit includes an LRC tank circuit comprising a transfer coil connected to a tuning box.
11. A method for testing the calibration of an instrument for measuring the polarization of a sample, wherein the instrument includes an NMR pickup coil connected to NMR pickup circuitry, said method comprising the steps of:
placing an active circuit adjacent to the NMR pickup coil, wherein said active circuit is coupled to the NMR pickup coil and responds as a hyperpolarized gas having a specific level of polarization when measured by the NMR pickup coil.
12. The method of claim 11 , further comprising the steps of:
positioning the active circuit within a calibrated polarization measurement device;
determining the apparent polarization of the active circuit; and
assigning the apparent polarization as the specific level of polarization.
13. The method of claim 12 , further comprising the step of:
adjusting the instrument for measuring the polarization of a sample so as to be calibrated to read the specific level of polarization of the active circuit.
14. The method of claim 11 , wherein said active circuit includes a transfer standard coil loosely coupled to the NMR pickup coil and NMR pickup circuitry.
15. The method of claim 14 , wherein said active circuit further comprises a high-Q oscillator circuit.
16. A method for calibrating a polarization measurement station having an NMR pickup coil connected to NMR pickup circuitry, comprising the steps of:
placing an active circuit adjacent to the NMR pickup coil, wherein said active circuit responds as a hyperpolarized gas having a specific level of polarization when measured by the NMR pickup coil; and
adjusting the instrument for measuring the polarization of a sample so as to be calibrated to read the specific level of polarization of the active circuit.
17. The method of claim 16 , further comprising the steps of:
positioning an active circuit within a calibrated polarization measurement device;
determining the apparent polarization of the active circuit; and
assigning the apparent polarization as the specific level of polarization.