JPH04130284A - Irradiation power control device in nmr device - Google Patents

Abstract

PURPOSE:To enable a required irradiation power to be set easily with a compact hardware and with less man-hours for adjustment by storing a standard irradiation power value corresponding to a plurality of probes as a file. CONSTITUTION:An output of an oscillator 3 is fed to a bin diode attenuator 4 through a setting volume 12 of irradiation power and then is applied to a probe 1. A CPU 9 reads a probe status signal from a probe 1, searches for a standard irradiation power value corresponding to it from a memory 10, and then writes it into a latch circuit of a CPU interface 8. A power value which is used finally is set from conditions written into the interface 8 and is set to a PLD 7. The PLD 8 sends digital signal corresponding to a power value from the interface 8 to a DA converter 6. The converter 6 sends analog signal to the attenuator 4, adjusts forward current flowing to the bin diode from this analog signal, and sets a required irradiation power value.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention adjusts the output of an oscillator for irradiation with a pin diode attenuator to set the required power value, amplifies it with a power amplifier, and applies it to the probe. NMR configured to
The present invention relates to an irradiation power management device in an apparatus.

[Conventional technology]

FIG. 5 is a diagram showing a conventional example of an irradiation power setting circuit.

Probes used in recent NMR instruments include C/H dual probes, tuner pull probes, H-(x) observation probes, etc., and these probes are more superior in heterodecoupling measurements between different nuclei. different R for each probe to obtain decoupled data.
F decoupling power is now required.

On the other hand, conventionally, about two types of decoupling powers have been used. For example, 9W or 4W is mainly used, and if lower power is required, the required power is obtained by varying the value of the attenuator of the irradiation oscillator. FIG. 5 shows an example of the configuration.

In a circuit where two types of irradiation power, 9W and 4W, are prepared, for example, as shown in FIG. The forward current of the pin diode is switched by a current control circuit 24 controlled by a signal.

In this configuration, when a 9W control signal is input, for example, the current control circuit 24 causes an appropriate current to flow through the pin diode attenuator 22 so that the irradiation power becomes 9W. The irradiation power of 9W is adjusted in advance by, for example, a semi-fixed adjustment resistor VR in the current control circuit so that the irradiation power becomes 9W.

[Problem to be solved by the invention]

However, in the conventional irradiation power setting circuit as mentioned above,
For example, if 10 types of decoupling powers are required, 10 types of control signals and power setting circuits are required, which makes the hardware large and expensive. Furthermore, when adjusting the decoupling power, 10 types of adjustments have to be made, which increases the number of adjustment steps and is time-consuming.

The present invention solves the above-mentioned problems, and provides an NMR apparatus that can easily set the required irradiation power with compact hardware and with less adjustment steps even when various types of irradiation power are required. The object of the present invention is to provide an irradiation power management device.

[Means to solve the problem]

To this end, the present invention adjusts the oscillator output for irradiation with a pin diode attenuator to set the necessary power value,
In an NMR apparatus configured to amplify with a power amplifier and apply it to a probe, a storage means for storing standard irradiation power values corresponding to multiple probes as a file, identifying the probe to be used and storing the standard irradiation power value irradiation power setting means for reading from the means and setting the irradiation power value to be used from the measurement conditions, digital signal conversion means for converting the set irradiation power value into a corresponding digital signal, and converting the digital signal into an analog signal. It is characterized in that it is equipped with a DA conversion means for sending data to a pin diode attenuator.

[Effect]

In the irradiation power management device in the NMR apparatus of the present invention,
Standard irradiation power values corresponding to multiple probes are stored in the storage means as a file, the probe to be used is identified, the standard irradiation power value is read from the storage means, and the irradiation power value to be used is set from the measurement conditions. It is possible to manage the irradiation power of many types of probes. Furthermore, the set irradiation power value is converted into a corresponding digital signal, which is then converted into an analog signal and sent to the pin diode attenuator, making it easy to set the signal sent to the pin diode attenuator from the set irradiation power value. Can be adjusted.

〔Example〕

Examples will be described below with reference to the drawings.

FIG. 1 is a diagram for explaining an embodiment of the irradiation power management system in the NMR apparatus according to the present invention, where 1 is a probe, 2 is a magnet, 3 is an irradiation oscillator, 4 is a pin diode attenuator, and 5 is a power amplifier for irradiation, 6 is a DA converter, 7 is a PLD (Programmable
8 is a CPU interface, 9 is a CPU, 10 is a memory, 11 is a keyboard, 12 is an irradiation power setting volume, and 13 is an irradiation curve selection switch.

In FIG. 1, the output of the irradiation oscillator 3 enters the pin diode attenuator 4 through the irradiation power setting volume 12, is adjusted to an appropriate RF output voltage, is amplified by the power amplifier 5, and is applied to the probe l. .

The memory 10 stores standard irradiation power values corresponding to each probe as a file.

The CPU 9 connects the probe 1 to the CPU interface 8.
The probe status signal is read in through the probe, the standard irradiation power value corresponding to the probe is searched from the memory 10, and the value is written into the latch circuit of the CPU interface 8.

Various measurement conditions such as high power decoupling and selective decoupling are also written in the CPU interface 8, and the power value to be finally used is set from all these conditions and sent to the PLD 7.

The PLD 7 sends a 12-bit digital signal corresponding to the power value input from the CPU interface 8 to the DA converter 6. The DA converter 6 converts the digital signal into an analog signal, and converts the analog signal into a pin diode. This signal is sent to attenuator 4.

The pin diode attenuator 4 adjusts the forward current flowing through the pin diode using this analog signal, and sets the required irradiation power value.

As described above, in the present invention, a file of standard irradiation power corresponding to each probe is created and stored in the memory 10 under the control of the CPU 9, and the file is read out to set the power and convert from digital signal to analog signal. Therefore, it can be easily rewritten and changed, and many types of irradiation power can be easily switched, set, and managed.

□ Blank space below □ The standard irradiation power file is as shown below. This irradiation power value is 1 byte 8
It is shown in base data, and a is INEPTSD.
b indicates the power value of a hard pulse (spin population transfer pulse) used in measurements such as EPT, b indicates the irradiation power value during off-resonance measurement, and C indicates the irradiation power value during complete decoupling measurement.

Here, if 2 bits out of 8 bits are assigned to a, 4 types of power can be expressed, and if 3 bits are assigned to b and C, 8 types of different powers can be expressed.

Next, the operation will be explained.

First, when a probe is replaced, a certain predetermined reading command is always input from the keyboard 11. In response to this command, the CPU 9 reads, for example, the type of probe attached to the magnet (probe status), and searches for a probe that matches the probe status signal from the standard irradiation power file in the memory.

If there is a match, the irradiation power data corresponding to the probe signal is read from the memory, and the data is stored in the latch circuit of the CPU interface 8.

The CPU interface 8 allows various measurement conditions to be
The reception has been taken from U9, and currently the irradiation power data aSb,
Select which data from c to use. For example, select C for complete decoupling measurement, select ``S'' for off-resonance measurement, and select ``a'' for spin population transfer pulse.

If C is selected, since C is represented by 3 bits, 8
Different types of decoupling power can be displayed.

The decoupling power value represented by C is, for example, as follows.

The decoupling power value represented by b is also similar to C. Further, the spin population transfer pulse power value represented by a is, for example, as follows.

The following describes how the probe input power is adjusted to 9W when 9W is selected in the margin 22.

In FIG. 1, when the pin diode attenuator 4 becomes the minimum, the output of the oscillator 3 is amplified by the power amplifier 5, and the probe input power becomes the maximum power. Therefore, if the probe input power is to be 9W, the forward current flowing through the pin diode is adjusted and reduced to 9W.

That is, when 9W is instructed by the CPU interface 8, the PLD converts it into a binary 12-bit digital signal corresponding to 9W, the 12-bit DA converter converts the digital amount to an analog amount, and the probe input power is sent to the bin diode. A forward current corresponding to 9W is applied.

In PLD7, 4W, 2WS 1.5W, 1.0W, 0
．． If there is an instruction such as 5W, the corresponding digital amount will be output. FIG. 2 is a diagram showing the relationship between the irradiation power instruction value and the PLD digital output value at the CPU interface. The input/output relationship of the PLD 7 can be calculated from the oscillation output level, pin diode attenuator, power amplifier gain, etc., but it is better to determine it as an experimental value so that the irradiation power can be set more accurately. Therefore, if a plurality of conversion curves, including those obtained as experimental values, are prepared so that they can be switched and adjusted, the correct irradiation power can be easily set.

Next, a description will be given of adjustment when the output voltages of the oscillators are different and the characteristics of the irradiation power amplifier vary.

Figure 3 shows the CP when the output voltage of the irradiation oscillator is different.
Irradiation power indication value and PLD at U interface
FIG. 4 is a diagram showing the relationship between the irradiation power instruction value at the CPU interface and the PLD digital output value due to the difference in linearity of the irradiation power amplifier.

If the output voltage of the irradiation oscillator 3 differs from the standard value shown in FIG. In such a case, adjust the irradiation power setting volume 12 so that the curve becomes a. Of course, if the oscillator and irradiation power amplifier are stable, the curve will always be a, and the correct power will be set.

Furthermore, if variations in the characteristics of the irradiation power amplifier occur, the result will be as shown in FIG. 4, and in this case as well, the correct irradiation power will not be set. In the figure, a is when the linearity of the irradiation power amplifier is the standard value, C is when the linearity of the irradiation power amplifier is more nonlinear than the standard value, and b is when the linearity of the irradiation power amplifier is more linear than the standard value. Indicates a certain case. In such a case, adjust the irradiation curve selection switch 13 to select a curve close to the standard value. As a result, the correct irradiation power is set.

Note that the present invention is not limited to the above embodiments, and various modifications are possible. For example, the irradiation power data stored in the memory has been described as 1-byte data, but if more detailed power discrimination is required, it does not need to be fixed to 1 byte and may be 16-bit word data. Further, although the three bits from the LSB of the irradiation power data are used as complete decoupling power, they may be off-resonance power or spin-population transfer pulse power, or the order may be changed. The multi-values of irradiation power and pulse power do not need to be fixed to the embodiments, and any value may be defined. D.A.
The converter was also explained as a 12-bit converter, but it is also a 16-bit DA.
It may be C. Although the device for storing the curves of irradiation power and spin population transfer pulse power is a PLD, it may be a ROM. moreover,
Although the level of irradiation power is set using a semi-fixed volume, it may also be set using a pin diode attenuator circuit and controlled by the CPU, and the selection of the irradiation power curve may be set using a switch, but may also be set using CPU control.

〔Effect of the invention〕

As is clear from the above explanation, according to the present invention, files of irradiation power and spin population transfer pulse power for each probe are stored in the memory, so that the irradiation power in a certain irradiation power file in the memory is stored in the memory. , the spin population transfer pulse power value can be rewritten by editing operations from the keyboard, and the values of the probe irradiation power and the spin population transfer pulse power can be easily changed. Therefore, the degree of freedom as an apparatus is increased, and an extremely easy-to-use apparatus can be provided, especially when experimenting with a new probe that has an experimental element.

Furthermore, it is possible to easily manage many different irradiation powers and spin population transfer pulse powers using the irradiation power file and hardware. Furthermore, since the PLD has a curve for each power, the irradiation power and pulse power only need to be adjusted at one place, which reduces the burden of adjustment.

Furthermore, since a switch for selecting the irradiation power curve is provided, deviations in irradiation power due to differences in linearity of the irradiation power amplifiers can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining one embodiment of the irradiation power management method in the NMR apparatus according to the present invention, and FIG.
A diagram showing the relationship between the irradiation power instruction value at the interface and the PLD digital output value. Figure 3 shows the relationship between the irradiation power instruction value at the CPU interface and the PLD digital output value when the output voltage of the irradiation oscillator is different. Figure 4 is a diagram showing the relationship between the irradiation power instruction value at the CPU interface and the PLD digital output value due to the difference in linearity of the irradiation power amplifier, and Figure 5 is a diagram showing a conventional example of the irradiation power setting circuit. It is. DESCRIPTION OF SYMBOLS 1... Probe, 2... Magnet, 3... Irradiation oscillator, 4... Pin diode attenuator, 5...
...Irradiation power amplifier, 6...DA converter, 7
...PLD (Programmable Logi
c Device@), 8-CPU interface,
9...CPU110...Memory, 11...Keyboard, 12...Irradiation power setting volume, 13.
...Irradiation curve selection switch. Applicant JEOL Co., Ltd. Agent Patent Attorney Ryukichi Abe (7 others) Figure 1 Figure 2 Figure 3 Tomoe Nogwara Indication Value Figure 4

Claims (4)

[Claims] (1) Standard irradiation compatible with multiple probes in an NMR device configured to adjust the irradiation oscillator output with a pin diode attenuator to set the necessary power value, amplify it with a power amplifier, and apply it to the probe. A storage means for storing the power value as a file, an irradiation power setting means for identifying the probe to be used and reading the standard irradiation power value from the storage means and setting the irradiation power value to be used from the measurement conditions, and the set irradiation power value. An irradiation power management device for an NMR apparatus, comprising: digital signal converting means for converting a digital signal into a corresponding digital signal; and DA converting means for converting the digital signal into an analog signal and sending it to a pin diode attenuator. (2) The irradiation power management device for an NMR apparatus according to claim 1, characterized in that a variable impedance for setting irradiation power is connected between the oscillator and the pin diode attenuator. (3) The digital signal conversion means has a plurality of conversion curves for converting the set irradiation power value into a digital signal, and the conversion curves are configured to be selectable by a selection switch. Irradiation power management device in NMR equipment. (4) The irradiation power management device for an NMR apparatus according to claim 1, wherein the irradiation power setting means is capable of updating a file in the storage means.