JPS6129454B2 - - Google Patents

Description

Detailed Description of the Invention The present invention relates to an electron spin resonance apparatus (ESR apparatus), and in particular to a wide range of quantitative measurements by changing the amount of a standard sample inserted into a cavity resonator in conjunction with the amplification degree of the apparatus. This article relates to an ESR device that can perform accurate operation over a wide range.

In an ESR device, for example, as shown in Figure 1, a standard sample R is inserted into a cavity resonator C along with a sample S to be measured, and the ESR signals of both are compared (specifically, the peak height or waveform Quantitative measurements are carried out by comparing the areas. The ESR signal actually obtained by the recorder during quantitative measurement includes signal A due to the standard sample and signal B due to the sample to be measured, as shown in FIGS. 2a and 2b. In comparison, it is preferable that both signals A and B have intensities close to the full scale of the recorder, since the signal intensities can be read more accurately and the comparison results will be more accurate.
However, since signal B varies by orders of magnitude depending on the type of sample, if the magnitudes of the two signals are extremely different as shown in Figure 2 a and b, even if one signal is adjusted to the full scale of the recorder, it will not work. The magnitude of the other signal could not be measured with sufficient precision, and therefore, in such cases, accurate quantitative measurements could not be performed.

The present invention solves the above-mentioned problems by changing the amount of a standard sample inserted into a cavity resonator in conjunction with the amplification degree of the apparatus.The present invention will be explained in detail below with reference to the drawings.

FIG. 3 is a configuration diagram showing an embodiment of the present invention, and in the figure, reference numerals 1 and 2 are magnetic poles arranged opposite to each other. A DC magnetic field is formed between the magnetic poles by a coil 4 to which excitation current is supplied from a power source 3. A cavity resonator 5 is arranged at the center of the magnetic field,
The resonator 5 includes a circulator, an attenuator,
Microwaves from a microwave oscillator 7 such as a Gunn oscillator are supplied by a waveguide via a microwave bridge circuit 6 comprising a phase shifter and the like.
Inside the cavity resonator 5, as shown in FIG. 4, a sample S to be measured is inserted, a standard sample 9 sealed in a thin quartz tube 8, and a dummy rod 1 made of quartz or the like.
0 is inserted, especially the standard sample 9 and the dummy rod 10.
are moved in conjunction with each other in opposite directions by a moving mechanism 11 provided outside the resonator.

When the matching of the resonator 5 breaks down due to microwave absorption due to electron spin resonance of the sample, the resonator 5
A reflected wave generated from the bridge circuit 6 and taken out via the bridge circuit 6 is detected by the microwave detector 12. The obtained detection signal is amplified by the preamplifier 13 and main amplifier 14 and sent to the recorder 15 for recording, but an attenuator 16 is inserted between the preamplifier 13 and the main amplifier 14 to adjust the gain. ing. The moving mechanism 11 operates in conjunction with the operation of the attenuator 16. Note that the recorder 15 is driven in synchronization with the magnetic field sweep by the power source 3.

In such a configuration, if the ESR signal waveform obtained when the attenuator 16 is set to an appropriate gain is that the signal B is extremely small as shown in FIG.
6 to increase the gain and make the signal B close to full scale. At this time, in the conventional device, signal A increases together with signal B, and the waveform becomes saturated, making it impossible to measure its intensity. However, in the present invention, when the attenuator 16 is operated in a direction to increase the gain, the standard sample 9 is pulled out from the resonator 5 by the moving mechanism 11 in conjunction with this, and the amount of the standard sample in the resonator is reduced. Therefore, even if the gain is increased, the signal A will not become saturated.
Therefore, a waveform as shown in Fig. 5 is obtained, and signal A is also similar to signal B.
Both can accurately measure strength. In addition, if the signal B is extremely large as shown in FIG. Since the amount of the standard sample increases and the signal A increases, it is possible to set the two signals A and B to approximately the same level, and then, if the gain of the main amplifier 14 is increased while leaving the attenuator unchanged, the result will be as shown in Figure 5. A waveform can be obtained, and the intensity of both signal A and signal B can be measured accurately. Therefore, accurate quantitative measurements can be performed.

Incidentally, if a scale indicating gain is attached to the attenuator and the attenuator is operated so that the intensities of signal A and signal B match, the gain at that time will indicate the signal intensity ratio. In this way, measurement becomes easy.

By the way, when a standard sample is inserted and removed in a resonator, the resonant frequency f ₀ and Q change, but in the present invention, a dummy rod is used that is inserted when the standard sample is pulled out, and pulled out when it is inserted. Since it is provided, such changes can be compensated for.

[Brief explanation of the drawing]

1 and 2 are diagrams for explaining the problems of the conventional technology, FIG. 3 is a configuration diagram showing an embodiment of the present invention, FIG. 4 is a sectional view of the cavity resonator, and FIG. FIG. 3 is a waveform chart for explaining the operation of the above embodiment. 5: Cavity resonator, 9: Standard sample, 10: Dummy rod, 11: Moving mechanism, 13: Preamplifier, 14:
Main amplifier, 16: Attenuator.

Claims (1)

[Claims] 1. In an electron spin resonance apparatus equipped with a cavity resonator into which a sample to be measured and a standard sample are inserted, the standard sample to be inserted into the cavity when the gain of the amplifier that amplifies the electron spin resonance signal is increased. The amount of
A standard inserted into the cavity resonator in conjunction with the gain of an amplifier that amplifies the electron spin resonance signal, such that when the gain decreases, the amount of standard sample inserted into the cavity increases. A standard sample moving mechanism is provided to vary the amount of the sample, and a standard sample is provided to prevent changes in the resonant frequency and Q of the cavity resonator due to changes in the amount of the standard sample inserted into the cavity resonator. An electron spin resonance device characterized in that a compensator is provided that can be moved into and out of a cavity resonator in a complementary manner.