NMR Measurement Method

• US 20080150527A1
• Filed: 02/20/2008
• Published: 06/26/2008
• Est. Priority Date: 04/11/2003
• Status: Active Grant

• Current Assignee: Jeol Resonance Inc. (JEOL Limited)
• Original Assignee: JEOL Limited
• Inventors: Hasegawa, Kenichi, Anai, Takahiro, Mizuno, Kentarou
• Granted Patent: US 7,570,053 B2
• Time in Patent Office: Days
• US Class Current: 324/307
• CPC Class Codes: G01R 33/31 Temperature control thereof
• CPC Class Codes: G01R 33/34023 Superconducting RF coils
• CPC Class Codes: G01R 33/3403 Means for cooling of the RF coils, e.g. a refrigerator or a cooling vessel specially adapted for housing an RF coil
• CPC Class Codes: G01R 33/34069 Saddle coils
• CPC Class Codes: G01R 33/34076 Birdcage coils
• CPC Class Codes: G01R 33/34092 RF coils specially adapted for NMR spectrometers
• CPC Class Codes: G01R 33/3635 Multi-frequency operation

Abstract

There is disclosed an NMR measurement method and NMR apparatus in which the temperature of the NMR detection coil or the RF irradiation coil hardly varies if pulsed RF power is applied to the coil during NMR measurements. The apparatus includes the detection coil or the RF irradiation coil, a first RF power application means for applying RF power of a frequency necessary for measurement of NMR signals, a second RF power application means for applying RF power of a frequency not affecting the measurement of NMR signals, and a control means for controlling the two power application means such that the sum of the RF power applied to the coil from the first application means and the RF power applied to the coil from the second application means is kept almost constant.

Claims

1. An NMR measurement method comprising the steps of:

applying RF power of a frequency not affecting measurement of an NMR signal to a detection coil or the RF irradiation coil such that reflected RF power is produced; and

detecting an increase in the temperature of the detection coil or the RF irradiation coil from the strength of the reflected RF power.

2. The NMR measurement method set forth in claim 1, wherein said detection coil or the RF irradiation coil has a resonance mode which is different from a resonance mode at a measurement frequency for the NMR signal and which does not affect the measurement of the NMR signal.

3. The NMR measurement method set forth in claim 1, wherein said frequency not affecting the measurement of the NMR signal is shifted from a measurement frequency for the NMR signal by a given frequency and can resonate in the same resonance mode as the measurement frequency for the NMR signal.

4. The NMR measurement method of any one of claims 1 to 3, wherein the RF power of the frequency not affecting the measurement of the NMR signal can be so adjusted that the ratio of the RF power reflected from the detection coil or the RF irradiation coil to the RF power applied to the detection coil or the RF irradiation coil is minimized.