SU494669A1 - X-ray Radiography Device - Google Patents

Description

one

The invention relates to an x-ray analysis apparatus.

A device for radiographing radioactive objects is known, comprising a radiation source, a goniometric device, a radiation detector, a drive for rotating the sample and detector, a modulator connected to the control generator, protective means from self-radiation of the sample, a measuring circuit.

The disadvantages of the known device are low accuracy inherent in analog devices, as well as the duration of the measurement and the complexity of the preparation of the obtained data for automatic processing.

The purpose of the invention is to accelerate the measurement and processing of the received data with the accuracy that digital devices provide.

According to the invention, the goal is achieved in that a device for converting an analog signal into a frequency is inserted into the device, and the sample and detector rotation drive is made in the form of a stepper motor, the input of which is connected to the output of the control generator.

FIG. 1 shows a diagram of the proposed device; in fig. 2 - timing diagram of the signal at the input or output of the elements of the device: a - waveform to the modulator; b-waveform background to the modulator; c is the total waveform and background to the modulator; r is the time distribution of the pulses from the output of the control generator; d-waveform after modulator; e - pulses at the output of the analog signal to frequency converter; W-reading of the pulse counter before digital printing or computers; 3 - the difference in the readings of the pulse counter at neighboring points in time.

The device is a goniometric device in the center of which sample 1 is located. But the goniometer is 120 ° apart from one another and there is an X-ray tube 2 with an entrance slit 3 and a radiation receiver 4. A modulator 5 is mounted in front of the radiation receiver 4 and magnet 6. The movement of the sample 1 and the radiation detector 4 is carried out by means of a stepper motor 7. The goniometric device is located in a protective box (not shown) behind the radiation source. Analog converter

signal to frequency 8, pulse counter 9 and control generator 10, made as a single unit, are placed outside the protective box and connected to radiation receiver 4 and recording device (for example, digital printing) device And, for example, type NL-150 and computer 12 using cable . The control generator 10 is connected to the stepper motor 7 and the pulse counter 9.

The device works as follows.

The radiation of the X-ray tube 2, the waveform of which is shown in FIG. 2, a, through the entrance slit 3 falls on the test sample 1. The diffracted radiation of sample 1 is modulated by the modulator 5 and enters the radiation receiver 4.

The shape of the modulation is chosen rectangular, which is more convenient in digital technology. The fronts of the rectangular pulses are determined by the control generator 10, the temporal distribution of the pulses of which is represented in FIG. 2, “the The thickness and material of the modulator 5 are selected so that only the diffracted radiation is modulated. The beta radiation of sample 1 is deflected by magnet 6 and does not enter the radiation receiver. Gamma radiation is hardly modulated due to differences in stiffness. Dispersed gamma radiation with energies close to the energy of the diffracted radiation does not enter the radiation receiver 4 if properly screened. From the output of the radiation receiver 4, the diffracted radiation, together with the gamma background of sample 1, enters the analog value converter at frequency 8. The pulses from the output of the converter 8 (Fig. 2, e) are fed to the counting input of the pulse counter 9, which reads them during the time between the intervals of the pulses (Fig. 2, g). The difference in neighboring readings (Fig. 2, h) gives a number proportional to the intensity of the diffracted radiation. If the pulse counter 9 is reversible, then this difference is obtained on the meter itself. If the pulse counter is not reversible, then the difference between the readings can be found during information processing.

on the computer 12. The stepper motor moves the sample 1 and the radiation detector 4. Movement using a scap motor allows changing the movement speed of the sample and the radiation receiver in a wide range by changing the frequency of the control generator 10. The control of the modulator 5 and the pulse counter 9 from common control generator 10

necessary to provide synchronous detection. The control from the same generator 10 by the stepping motor 7 makes it possible to unambiguously determine the location of the sample I and the radiation receiver 4 according to the reference number, knowing the position of the sample 1 and the receiver 4 at the first count. The use of a controlled IlM pulses divider between the generator 10, the modulator 5 and the pulse counter 9 allows you to change

the number of samples for the same sample transfer 1 and radiation receiver 4, keeping the conditions of synchronous detection.

Subject invention

A device for radiographing radioactive materials containing a source and a radiation detector, a goniometric device, a drive for rotating a sample and a radiation detector, protective equipment, a modulator connected to a control generator, in order to speed up the measurement and processing of the obtained data An analog signal-to-frequency conversion circuit, and the sample and detector rotation drive are made in the form of a stepper motor, the input of which is connected to the output of the control generator.

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