Hitachi, Ltd.

Yuzo Fukuda

Kazuo Saitoh

Michiya Okada

Hiroyuki Tanaka

Hiroyuki Yamamoto

Kenji Kawasaki

Tsuyoshi Wakuda

Norihide Saho

Hiromitsu Seino

Shuya Hagiwara

A probe for nuclear magnetic resonance (NMR) measurement provided with a multiple resonant circuit for detecting signals of two or more nuclides with high detection efficiency for nuclide at low resonant frequency comprises a multiple resonance radio frequency (RF) coil circuit that, with multiple lead lines connected to the RF coil, causes a part of the RF coil, separated by the connection points of the lead lines, to function as the inductor of a trap circuit that cuts off a signal at the frequency Ffor a signal at the resonant frequency Fof a first nuclide and, at the same time, to function as an RF coil that detects a signal at the frequency Ffor a signal at the resonant frequency Fof a second nuclide, thus increasing the signal detection efficiency for the nuclide at the frequency F.

Probe for NMR measurement

A low temperature probe having a coil used in an NMR apparatus includes an opposed heat exchanger cooling a cooling medium, and a cooling apparatus having a first cooling stage capable of cooling to no more than 10K and a second cooling stage capable of cooling to at least 10K in series cooling the cooling medium from the opposed heat exchanger. A probe portion has a first heat exchanging portion executing heat exchange between the cooling medium and the coil, a circulation structure which circulates the cooling medium into the opposed heat exchanger, a second heat exchanging portion executing heat exchange between the cooling medium and a heat radiation shield. The heat radiation shield has a heat capacity greater than the heat capacity of the cooling medium.

Low temperature probe and nuclear magnetic resonance analysis apparatus using the same

A probe for a nuclear magnetic resonance apparatus comprises: a transmission coil for irradiating a sample with a high-frequency electromagnetic wave; and a receiving coil for detecting a nuclear magnetic resonance signal emitted by the sample, wherein a selector switch is disposed to the transmission coil to reduce the deterioration of sensitivity of the receiving coil by switching the resonance state of the transmission circuit between during irradiation and during detection, even if an electromagnetic coupling remains between transmission and reception.

Probe configured for NMR apparatus and NMR apparatus using the same

There is provided a nuclear magnetic resonance probe in which the loss caused by a high frequency cable between a probe coil and a preamplifier is reduced and the sensitivity of an NMR signal is improved. A changeover switch for NMR probe is divided into a switch part including switch elements and a filter part for filtering a switch control signal and an RF transmission signal. The switch part is disposed in a probe body inserted in a magnet of the probe. The filter part is disposed near a measurement apparatus located outside the probe. As for the switch part, a section structure of thickness and width is reduced in conformity with a narrow and slender shape of the probe body. The length of a high frequency cable between the probe coil and the preamplifier is shortened remarkably, and consequently the loss can be reduced.

Nuclear magnetic resonance (NMR) probe

A NMR probe which causes only a minimum disturbance to magnetic-field uniformity, and which acquires a high resonant Q value. A detection coil 1 for detecting a nuclear magnetic resonance signal emitted from a sample 3 measured, and a compensation coil 4 composed of a superconducting material for compensating for inductance of the detection coil 1 are electrically connected in series with each other. Moreover, a tuning-dedicated variable capacitor 6 is connected to the detection coil 1 in series therewith, and a matching-dedicated variable capacitor 5 is connected to the compensation coil 4 in series therewith. Furthermore, a coaxial cable 9 is connected to both ends of the matching-dedicated variable capacitor 5. This configuration allows detection of the signal.

Compensated NMR probe with high Q value for NMR apparatus

The invention provides a low temperature probe having a high sensitivity by reducing a heat intrusion into a receive coil. A heat making an intrusion into a coil is suppressed by inserting a heat radiation shield in which a temperature is controlled at about 100 K to a portion between an outer container of a probe and a coil portion. A heat radiation shield bore sleeve is provided in a heat radiation bore, is connected to the heat radiation shield, and is cooled by a second heat exchanger. Further, the coil portion is cooled by a first heat exchanger. In preparation for a contraction at a time of being cooled, the outer container, the heat radiation shield and the coil portion are connected by using a fixing portion, and a heat relieving mechanism or a contraction relieving mechanism is provided in a root side (an opposite side to the fixing portion) of the heat radiation shield and the coil portion. The fixing portion is formed in a shape and made of a material having a small heat intrusion amount and having a small heat contraction.

Low temperature probe for NMR and NMR device

In an ultrahigh sensitive NMR apparatus, a stability of a temperature of a very low temperature probe coil is improved. A low temperature probe of the high sensitive NMR apparatus is structured at a very low temperature by a cooling apparatus. A cooling medium at a room temperature (300 K) discharged from a compressor is cooled down to 70K by a countercurrent heat exchanger, and is next cooled down to 4K or less by a series of second stages. Further, the cooling medium enters into a low temperature probe via a transfer tube, cools a probe coil to 5 to 10K by a heat exchanging portion, further cools a radiation shield to 40 to 60K, and makes a circuit via the countercurrent heat exchanger. A high temperature stability can be applied to a receiving probe coil in the low temperature probe by a cooling apparatus having a high temperature stability.

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Hitachi, Japan

Yuzo Fukuda