Electricity: measuring and testing – Particle precession resonance – Spectrometer components
Patent
1992-03-06
1994-03-29
Arana, Louis
Electricity: measuring and testing
Particle precession resonance
Spectrometer components
324315, G01V 300
Patent
active
052988643
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a nuclear magnetic resonance spectrometer comprising a sample holder which is arranged in a constant magnetic field of a predetermined direction and which comprises a rotor adapted to receive a sample, the rotor being arranged to rotate about a first axis which is inclined to the said predetermined direction at an acute angle of, preferably, 54.7.degree., and means being provided for heating up the rotor.
The present invention further relates to a nuclear magnetic resonance spectrometer comprising a sample holder adapted to receive a sample, and a laser the laser beam of which is directed upon a surface of the sample holder.
Finally, the present invention relates to a method for measuring the nuclear magnetic resonance of a sample, where the sample is heated up during the measurement to a temperature above ambient temperature, by means of a laser beam.
U.S. Pat. No. 4,201,941 describes a nuclear magnetic resonance spectrometer where a sample head comprises a sample holder which in its turn contains a rotor adapted to a receive a sample substance. The rotor of this known nuclear magnetic resonance spectrometer is adapted to rotate about an axis which is inclined relative to the longitudinal axis of the sample head and, thus, relative to the direction of the surrounding constant magnetic field, at an angle of 54.7.degree., known as the "magic angle". As is generally known, the "magic angle" of 54.7.degree. results from a term of a Legendre's polynomial according to which 3 cos.sup.2 .THETA.-1=0. If a sample of a solid body is rotated, during a nuclear magnetic resonance measurement, about an axis which is inclined relative to the direction of the constant magnetic field by the "magic angle", then any interactions will be averaged out to the greatest possible degree, whereby a simplified spectrum is obtained.
In the case of the known spectrometer, rotation of the rotor is ensured by a turbine-like arrangement. The rotor is provided for this purpose with a conical section with engraved areas configured in the manner of turbine blades.
The conical section is received in a matching conical receiving opening of a stator which is fixed to the sample head. Inside the conical receiving opening, nozzles are arranged along a circumference for introducing a propellant gas. This arrangement ensures not only a turbine drive for the rotor, but at the same time an air-cushion bearing for the rotor in the receiving opening.
The known nuclear magnetic resonance spectrometer is further equipped, in the immediate neighborhood of the rotor, with a temperature sensor serving for monitoring the temperature of the propellant gas and, thus, of the sample.
Although this fact is not expressly mentioned in U.S. Pat. No. 4,201,941, it has been known in connection with nuclear magnetic resonance spectrometers of the before-mentioned type to control the temperature of the sample via the temperature of the propellant gas, which can be achieved, for example, by heating up the compressed air which is to be blown into the sample head as air cushion and for driving the rotor.
However, this manner of proceeding is connected with the disadvantage that a relatively large quantity of temperature-controlled propellant gas is required for controlling the temperature of the sample, and this in particular in the case of high-temperature measurements on samples, where a correspondingly high volume of high-temperature gas will be required. Further, it is a drawback of this method that due to the before-mentioned manner of controlling the temperature via the propellant gas, all parts of the sample head which get into contact with the gas are automatically heated up as well. This firstly leads to increased energy consumption required for heating up the gas, and further results in the additional serious drawback that the entire area of the sample head will be heated, including those parts for which such heating-up is undesirable. This applies in particular to the receiving coil whose thermal background noise will be greatl
REFERENCES:
patent: 4940942 (1990-07-01), Bartuska et al.
patent: 4958126 (1990-09-01), Brevard et al.
Doutures Jean-Pierre
Massiot Dominique
Muller Detlef
Taulelle Francis
Arana Louis
Bruker Analytische Messtechnik GmbH
Hamrick Claude A. S.
LandOfFree
Nuclear magnetic resonance spectrometer and method for measuring does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Nuclear magnetic resonance spectrometer and method for measuring, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Nuclear magnetic resonance spectrometer and method for measuring will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-794904