RU27901U1 - DEVICE FOR ANALYSIS OF LUMINESCENCE CHARACTERISTICS - Google Patents

Abstract

1. A device for analyzing the characteristics of luminescence, containing a source of exciting radiation with a high-frequency generator, a holder for the object under study, a luminescence recording system including a photodetector based on a photoelectronic multiplier, the output of which is connected to a luminescence signal amplifier, an analog-to-digital converter and a processing device, a synchronizer, the first output of which is connected to the control input of the exciting radiation source, and the second to the control input of the device bots and an output data indication device, characterized in that additional low and high frequency filters are introduced, the inputs of which are connected to the amplifier output, the low-pass filter output is connected directly to the first signal input of an analog-to-digital converter made in the form of a multi-channel device, and the filter output the high frequency is connected to the second signal input of the analog-to-digital converter through a peak detector, the digital outputs of the analog-to-digital converter are connected by a data bus x with similar inputs processing apparatus configured as an arithmetic logic unit or a microprocessor, the output of which is connected to the gain control input of amplifier luminescence signals, wherein the third output connected to an input synchronizer start analog-digital preobrazovatelya.2. The device according to claim 1, characterized in that a second photodetector based on a photoelectron multiplier, a second luminescence signal amplifier, the output of which is connected �

Description

B07C 5/342, GOIN 21/64, GOIN 23/22

DEVICE FOR ANALYSIS OF CHARACTERISTICS OF LUMINESESIA

The proposed utility model relates to the field of analytical instrumentation, namely, devices for analyzing the luminescence characteristics of materials arising under the influence of exciting radiation, and, in particular, can be used to study the luminescence of a number of natural minerals under the influence of x-ray radiation, for example diamonds and related minerals.

A device for analyzing the afterglow of light-emitting material 1, containing a source of exciting radiation (IVI), a photoelectric converter (FPU), perceiving the afterglow of the sample, analog-to-digital converter (ADC), receiving the output signal of the FPU, the operating circuit, which calculates the peak separately from the output signals of the ADC. the intensity of the afterglow of the sample and the intensity of the afterglow at a certain point in time, as well as a unit for separate indication of the output values of the operating circuit.

The luminescence of materials and, in particular, minerals, in the general case is characterized by at least two components - components: short-lived 5th; fast or fast component (BC) with a rise and fall time of the order of units of microseconds 5T1d and a long-lived or slow component (MK) with time acceleration and the order of units of milliseconds. Therefore, the lack of measurement capabilities of BK is a significant drawback of the analyzer, since it narrows the possibilities of revealing the characteristic features of the analyzed luminescent material.

This device allows one to measure the amplitude and kinetics (the process of changing in time) of the slow component of luminescence, including separately determining its maximum amplitude. However, the lack of measurement capabilities of BK is a significant drawback of the device, as it narrows the possibilities of identifying the characteristic features of the analyzed luminescent material.

The closest analogue of the proposed utility model is a portable luminescent analyzer 2, containing a source of exciting radiation (IVI) with a high-frequency generator, a photoelectronic multiplier, a DC amplifier of luminescence signals, an analog-to-digital converter, a measurement system trigger (synchronizer), a data processing device, made in the form of a storage device, and an indication device.

The analyzer allows you to measure the amplitude and kinetics of only the slow component of luminescence. However, it lacks the ability to measure BK, which narrows the possibilities of identifying the characteristic features of the analyzed luminescent material. For example, to separate diamonds from related minerals, knowledge of not only the amplitude and kinetics of MK of the luminescence of a mineral, but also the amplitude of its BK, or the ratio of the amplitudes of BK and MK, is essential.

In addition, it is often important to determine the measure of transparency of materials with respect to intrinsic luminescence (amplitude and kinetics of MK and amplitude of BK), i.e. take luminescence measurements in absorption mode. The absence of such a measurement mode is also a disadvantage of the analyzer.

Another drawback of the analyzer is the inability to identify or select luminescent objects according to the specified boundary values of the luminescence characteristics.

The problem is solved by a device for analyzing the characteristics of luminescence, containing a source of exciting radiation with a high-frequency generator, a holder for the object under study, a luminescence recording system including a photodetector based on a photoelectron multiplier, the output of which is connected to a luminescence signal amplifier, an analog-to-digital converter and a processing device, a synchronizer whose first output is connected to the control input of the exciting radiation source, and the second to the input of the processing device and the device for indicating the output data, while additionally low and high frequency filters are inserted into the device, the inputs of which are connected to the amplifier output, the output of the low frequency filter is connected directly to the first signal input of the analog-to-digital converter made in the form of a multi-channel device and the output of the high-pass filter is connected to the second signal input of the analog-to-digital converter through a peak detector, the digital outputs of the analog-to-digital converter of Tell schinoy joined with similar data input processing apparatus configured as an arithmetic logic unit or a microprocessor, the output of which is connected to the gain control input of amplifier luminescence signals, wherein the third output connected to an input synchronizer start analog-to-digital converter.

In contrast to the known device, low and high frequency filters are added to the proposed device, the inputs of which are connected to the amplifier output, the low-pass filter output is connected directly to the first signal input of an analog-to-digital converter made in the form of a multi-channel device, and the high-pass filter output is connected to the second signal input of the analog-to-digital converter through a peak detector, the digital outputs of the analog-digital converter are connected by a data bus with the same name passages processing apparatus configured as arifmetikologicheskogo device or a microprocessor, whose output is connected to the input of gain control amplifier luminescence signals, wherein the third output connected to an input synchronizer start analog-converter.

In addition, to enable measurement of luminescence in the absorption mode, a second photodetector based on a photoelectron detector, a second luminescence signal amplifier, the output of a second low-pass filter, is connected directly to the third signal input of a multi-channel analog-to-digital converter, can be additionally introduced into the proposed device and the output of the second high-pass filter is connected to the fourth signal input of a multi-channel analog-digital of the transducer through the peak detector, the second output of the processing device is connected to the input 5 of the gain control of the second amplifier of the luminescence signals, while the optical input of the second photodetector is located on the other side of the plane perpendicular to the direction of the flow of exciting radiation and passing through the holder of the object under study.

To enable identification or selection of luminescent objects according to predetermined boundary values of the luminescence characteristics, a threshold value adjuster can be introduced into the proposed device, the output of which is connected to an additional input of the processing device, which is equipped with an additional output of the identification signal of the studied object.

To enable the analysis of X-ray luminescence of minerals, the source of exciting radiation can be made on the basis of an X-ray tube.

In FIG. 1 presents one of the variants of the structural diagram of the proposed device for analyzing the characteristics of x-ray luminescence of minerals.

Figure 2 shows the timing diagrams of the irradiation, synchronization and registration signals of the luminescence signals: a - exposure pulses;

b - luminescence signal at the output of photodetectors; c - MK signal of luminescence at the output of low-pass filters; g - the signal of the luminescence CD at the output of the peak detectors; d - trigger signals of the analog-to-digital Converter; e - signals for overwriting data from the ADC to the processing device.

Presented in FIG. 1, a device for analyzing the X-ray luminescence characteristics of minerals contains a transparent holder (not marked in FIG. 1) in the studied object 1, an exciting source (IVI) based on an X-ray tube with a high-frequency generator (not shown in FIG. 1) , synchronizer (SP) 3, photodetectors (FPUs) 4 and 5, made on the basis of photomultipliers (PMTs), first and second amplifiers (US) 6 and 7 luminescence signals, two pairs of filters 8, 9 and 10, 11 low (PLL ) and high (HPF) frequencies, respectively oh, peak detectors (PD) 12 and 13, a multi-channel analog-to-digital converter (ADC) 14, processing device 15 (UO), device 16 for indicating and presenting data (MI) and threshold value setter 17 (HST) for identifying objects by boundary values of the characteristics of dpominiscence. The outputs of the FPU 4 and 5 are connected, respectively, with the amplifiers 6 and 7 of the luminescence signal, the outputs of which through, respectively, the FPF 8 and 9 are directly connected to the first and third inputs of the ADC 14, and the outputs of the HPF 10 and 11 are connected, respectively, to the second and the fourth inputs of the ADC 14 through the peak detectors 12 and 13, the digital outputs of the ADC 14 are connected by a data bus with the inputs O O 15 of the same name, the first and second outputs of which are connected to the control inputs of the amplifiers 6 and 7, the third output is connected to the input of the AM 16 output HWP 17 is connected to an additional input UO 15, which is equipped with an additional output

ID of the identification signal of the investigated object. The first output of SI 3 is connected to the control input of IVI 2, the second to the engaging input of UO 15, and the third to the input of the ADC start 14.

A device for analyzing the characteristics of x-ray luminescence of minerals, shown in figure 1, operates as follows. The synchronizer 3 periodically starts and then interrupts the radiation of the IVI 2. At the same time, the test object 1 placed on the holder, located on the optical axis of the IVI 2, is periodically irradiated with a packet of x-ray pulses, the repetition rate and shape of which repeats the pulses of the high-frequency IVI 2 generator (Fig. 2a) . As a result, the test object 1 emits luminescent radiation in the optical wavelength range, which, when it reaches the optical input of the FPU 4 and FPU 5, is converted by them into an electrical signal (Fig.2b). The type of signals at the output of the FPU 4 and 5 is similar, but the specific ratio depends on the characteristics of the studied object 1. These signals are amplified by the amplifiers 6 and 7 of the luminescence signal and from their outputs are fed to the inputs of the filters HPF 8 and 9 and HPF 10 and 11. The output signal The FPF 8 and 9 (Fig.2c) has the form of an increasing and then decaying exponent. The signal at the output of the high-pass filter 10 and 11 repeats the shape of the pulses of the high-frequency generator RSI 2 (figa). After the radiation from the IVI 2 is interrupted by the synchronizer 3, the signal at the output of the high-pass filter 10 and 11 ceases and the peak detectors 12 and 13 emit the maximum value of the transmitted signal, i.e. determine the amplitude of the BC luminescence signal (Fig.2g). The synchronizer 3 with a signal from the third output starts the conversion of the signals supplied to the inputs of the ADC 14, at the time of interruption of the radiation of the IVI 2 and then periodically (Fig.2d) with a certain start period T3, for example, after 200 μs. According to the signal from the second output of the synchronizer 3 (Fig.2e), which enters the data processing device 15 with a delay relative to the pulses (Fig.2d) for the time AD conversion of the ADC 14, the conversion result from the digital data bus of the ADC 14 is transmitted to the data processing device 15. The first signal,

crawled at the moment of excitation interruption in the first and third channels of the ADC 14 is interpreted in UO 15 as the amplitude UMK of the slow component (MK) of the luminescence signals, respectively, in the direction of emission and absorption, and in the second and fourth channels of the ADC 14 as the amplitude of the UBK fast component (BK) luminescence signals in the direction of emission and absorption, respectively. The subsequent measurement results in the first and third channels of the ADC 14 reflect the kinetics of MK (the dependence of MK on time). The second and subsequent measurements in the second and fourth channels of the ADC 14 are not informative, since the BC attenuation by this time. The number of pulses (fig.2d, e) is determined by the period T3 of the launch of the ADC 14 and the maximum value of the duration 1d MK. For example, with T3 of 200 ISS and 1d of 20 ms, 100 pulses of the ADC start are necessary (Fig.2d, f). The measurement results are displayed from the UO 15 in the display device and data presentation UI 16.

Since the dynamic range of the possible values of the amplitudes UMK and UBK is very large (several orders of magnitude), gain control of the US 6 and 7 makes it possible to increase the gain in steps at small values of the luminescence signal. For example, if you select four steps “X 4 to change the gain, then if the ADC 14 output code is less than a quarter of the scale during the first“ marginal measurement, the gain is increased by one step, if the code value for “marginal measurement less than 1/16 of the scale, the gain increases by 2 years, if less than 1/64 of the scale - by 3 steps, if less than 1/256 of the scale - by 4 steps. After completing the entire series of measurements of this object, the amplification in DC 6 and 7 returns to the initial (minimum) value. The luminescence characteristics in emission and absorption (in FPU channels 4 and 5, respectively) are measured at the same time, but the gain of US 6 and 7 is controlled separately from UO 15. At NI 16, the numerical values of the amplitudes UMK and UBK and the attenuation curve of the MC in the form of a table in the coordinates “time - intensity. By representing the MK curve in the form of an exponent, you can calculate the exponent parameter - time constant tmk. To select objects 1 according to one or more luminescence characteristics, the proposed device has a limiter 17 of boundary values, the function of which is to enter in UO 15 numerical values of one or more luminescence characteristics as threshold . In UO 15, the values of the measured characteristics of the analyzed object 1 are compared with the threshold values from the HW 17. If the characteristics of object 1 fall within the specified limits of the threshold values, then UO 15 generates a logical signal ID 1, which can be used to separate objects 1 with the specified luminescence characteristics from the set of analyzed objects 1.

An amplifier with a controlled gain can be performed, for example, on two microchips of programmable amplifiers of the AD526JN type from Analog Devices (USA) 3, each with amplification from x1 to x16.

A multi-channel ADC can be performed, for example, on the basis of the AD7891AP-1 chip of Analog Devices (USA) 4.

The synchronizer can be performed, for example, on the basis of microcircuits of the pulse generator 1006VI1, counters K555IE7 (2 pcs.) And decoder K1533IDZ 5.

Thus, the proposed device for analyzing the luminescence characteristics provides enhanced opportunities for the analysis of the luminescence of materials by separately measuring the fast and slow components of the luminescence signal of the analyzed object, which allows you to more accurately determine its properties, including the measure of transparency in relation to the luminescence excited in it, to reliably identify and select an object with specified properties from the set of analyzed objects.

Sources of information:

1.Act. Japanese Application No. 6050286, G01N 21/64, 06/29/94

2. RF patent No. 2085911, G01N 21/64, 07.27.97.

3.http: //www.analog.com. Programmable Amplifier AD526JN.

4.http: //www.analog.com. ADC: 8 channels, 12 bits, 500 kHz AD7891AP-1.

5.G.I. Pukhalsky, T.A. Povoseltseva. Design of discrete devices on integrated circuits. M. Radio and Communications, 1990.

Claims (4)

1. A device for analyzing the characteristics of luminescence, containing a source of exciting radiation with a high-frequency generator, a holder for the object under study, a luminescence recording system including a photodetector based on a photoelectronic multiplier, the output of which is connected to a luminescence signal amplifier, an analog-to-digital converter and a processing device, a synchronizer, the first output of which is connected to the control input of the exciting radiation source, and the second to the control input of the device bots and an output data indication device, characterized in that additional low and high frequency filters are introduced, the inputs of which are connected to the amplifier output, the output of the low frequency filter is connected directly to the first signal input of an analog-to-digital converter made in the form of a multi-channel device, and the filter output the high frequency is connected to the second signal input of the analog-to-digital converter through a peak detector, the digital outputs of the analog-to-digital converter are connected by a data bus x with similar inputs processing apparatus configured as an arithmetic logic unit or a microprocessor, the output of which is connected to the gain control input of amplifier luminescence signals, wherein the third output connected to an input synchronizer start analog-to-digital converter.  2. The device according to claim 1, characterized in that a second photodetector based on a photoelectron multiplier is additionally introduced in series, a second luminescence signal amplifier, the output of which is connected to the inputs of the second low and high frequency filters, the output of the second low-pass filter is connected directly to the third the signal input of the multi-channel analog-to-digital converter, and the output of the second high-pass filter is connected to the fourth signal input of the multi-channel analog-to-digital converter through the peak detector, a second processing device output is connected to an input of the second gain control amplifier luminescence signals, wherein the optical input of the second photodetector is located on the other side of the plane perpendicular to the direction of the exciting radiation flux passing through the holder and the test object.  3. The device according to claim 1, characterized in that the source of exciting radiation is made on the basis of an x-ray tube. 4. The device according to claim 1, characterized in that the threshold value adjuster is additionally introduced, the output of which is connected to an additional input of the processing device, which is equipped with an additional output of the identification signal of the object under study.