RU1304656C - Device for recording ionizing radiation - Google Patents

Abstract

The invention relates to the field of experimental nuclear physics and radiation instrument engineering. The purpose of the invention is to improve measurement accuracy. The essence of the technical solution is that a second integrator and a third key are introduced into the known device, connected by an information input to the output of the current generator, a hydraulic input - to the first, first output of the control unit and an output - to the output of the first key and to the input of the second integrator, the output of which is the output of the device, the information input of the second key is connected to the output of the scintillation detector. The use of the invention provides improved accuracy in detecting radiation by reducing the contribution of the random component of the spurious signal. 1 ill. § (L s 00 o 35 SP CX)

Description

The invention relates to the field of experimental nuclear physics and radiation instrumentation, in particular, to devices for measuring the field parameters of pulsed ionizing radiation sources for protection of complex geometric shapes and for non-destructive testing of materials, substances and products with a scintillation method of detecting radiation. The aim of the invention is to increase the accuracy of measurements under the conditions of fluctuations in the dose rate and the ambient temperature.

The drawing shows a functional diagram of a device for detecting ionizing radiation.

The device comprises a scintillation detector 1, keys 2,3, integrators Au 5, a current generator 6, a key 7 and a control unit 8.

The output of the scintillation detector 1 is connected to the information inputs of the keys 2 and 3, the control inputs of which are connected to the first and second outputs of the control unit 8, respectively. Key 2 output connected to input

integrator, the output of which is the output of the device. The output of the key 3 is connected through a series-connected integrator 5 and a generator 6

current to the information input of the key 7 connected to the control input and output, respectively, to the control input and output of the key 2.

A device for detecting ionizing radiation operates as follows.

In the initial state, at the end of the previous ionizing pulse, the keys 2 and 7 are closed, and the key 3 is open upon command from the outputs of the control unit 8. During the passage of a control (synchronization) pulse, signals are transmitted to the input of the control unit from its first and second outputs, by which keys 2 and 7 are opened and key 3 is locked. The detected pulse of ionizing radiation, when interacting with the scintillation detector I, is converted into a current pulse, which, through the public key 2, is fed to the input of integrator A. The signal from integrator 4 is fed to the output of the device for further processing. At the end of the radiation pulse after a fixed time from the moment of opening the keys 2 and 7

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(equal to or slightly longer than the duration of the Radiation pulse) by signals from the control unit, keys 2 and 7 are closed and key 3 is unlocked.

At this point, the registration of one radiation pulse ends. However, when registering radiation, in addition to the informative signal, the parasitic signal is also supplied to the integrator 4, due to the dynamic noise of the scintillator (slow and super slow components of the light scintillator pulser), the noise of the photomultiplier PMT, and induced activity as a result of nuclear reactions in the detector material and the object (protection).

The spurious signal upon registration of a pulse of ionizing radiation leads to measurement error. The largest contribution of the spurious signal to the measurement error is observed when monitoring products (protection) with an inhomogeneous structure or complex geometric shape, when the dose rate level at the input of the recording device changes by two or more orders of magnitude and the measurement signal becomes comparable with the level of the spurious signal.

The correction circuit, consisting of a series-connected key 3, an integrator 5, a current generator 6 and a key 7, reduces the contribution of the spurious signal to the error of radiation registration. Before the start of the measurement cycle (after the end of the previous radiation pulse), the keys 2,3,7 by the signal from the control unit 8, they are set to the initial state, the keys 2,7 are closed, the key 3 is open. In this case, the spurious signal through the open key 3 is fed to the input of the integrator 5, which averages and inverts the noise signal. When a synchronization pulse appears prior to the detected radiation pulse, the key 3 closes. , and the keys 2.7 are open-. Through the public key 2, ff information and spurious signals are received at the input of the integrator 4 from the output of the scintillation detector I.

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and from the output of the integrator 5 through the current generator 6 and the public key 7 to the input of the integrator 4 receives a compensation signal, equal in magnitude

and opposite in sign to the spurious signal. After a time equal to (or slightly longer) the duration of the radiation pulse by the signals from the control unit 8, the keys 2 and 7 are closed and the key 3 is opened. This ends the cycle of recording one radiation pulse.

The spurious signal from the output of the scintillation detector 1 and the compensation signal from the output of the key 7 arrive at the input of the integrator 4 only at the moment of the appearance (registration) of the radiation pulse, which ensures along with full compensation of the constant component of the larazite signal and a decrease in its contribution random component.

If the scintillation detector I includes a current to voltage converter, which is necessary, in particular, for the detector to work at a matched load when it is significantly removed from the recording device, the 2.7 switches must include series-connected voltage-to-current converters ( resistors). In this case, the operation algorithm of the entire device during registration of radiation is preserved.

The use of the invention provides a reduction in error when

Compiled by V. Kostyukhin Editor N. Kogan Tehred c. Kadar

Order 1099 Circulation

VNIIIPI of the State Committee of the USSR. On Inventions and Discoveries

  1J3035, Moscow, Zh-35, Rauska nab., D. 4/5

Production and printing company, Uzhgorod, ul.Proektna,

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registration of radiation due to a random component to 41% by reducing the contribution of the random component of the spurious signal, and also helps to increase the stability of the device.

Claims (1)

The claims A device for recording ionizing radiation, comprising a scintillation detector, two keys, a first integrator, a current generator and a control unit, the first and second outputs of which are connected respectively to the control inputs of the first and second keys, the information input of the first key is connected to the output of the scintillation detector, and the output of the second key is connected through the first integrator to the input of the current generator, characterized in that, in order to increase accuracy, a second integrator and a third key are connected to it, connected data input to the output of the current generator, a control input - to the first output of the control unit and output - to the output of the first switch and to the input of the second integrator whose output is the output devices, and data input of the second switch is connected to the output of scintillation detector. Proofreader E. Roshko