Neutron Irradiation Calibration System PM9200 is designed for automated verification, calibration, graduation, and testing of the instruments that measure flux density, ambient dose equivalent rate, and personal dose equivalent rate of neutron radiation.
PM9200 provides the field of fast and thermal neutrons in a collimated beam as well as in an open geometry. The field is created by sealed neutron sources 238Pu-Be, 239Pu- BE, 241Am-Be, and 252Cf used in the system irradiator.
PM9200 is available in three models which differ in irradiators.
| at reproduction of neutrons flux density | 5% |
| at reproduction of ADER and PDER | 7% |
| for NI-204 (РМ9200) | up to 4 |
Operation Principle
The system provides a wide range of reference dosimetric values by using the neutron sources of different activity and changing the distance between the source and the instrument. The sources are stored in a fixed irradiator equipped with one or multiple compartments for them. The distance change is ensured by linear positioning system.
A special metrological software installed on the operator's workstation allows selecting the required source, setting the distance between the source and tested instrument, adjusting the instrument position in the collimated beam, and calculating the exposure duration either automatically or manually.
System components
- Neutron irradiator
- NI-201 (for РМ9201)
- NI-201Н (for РМ9201Н)
- NI-204 (for РМ9200) - Linear positioning system
- Video surveillance system
- Operator workstation
- Control system
- Radiation monitoring system PM520
Irradiator
The remote-control irradiator ensures storage and operation of sealed neutron radiation sources 238Pu-Be, 239Pu-BE, 241Am-Be and 252Cf (by the customer's request).
— NI-201 irradiator provides underground location and storage of one neutron source with maximum neutrons flux of up to 5х108 counts per second (cps).
— NI-201Н irradiator provides ground location and storage of one neutron radiation source with maximum neutrons flux of up to 1х107 cps.
— NI-200 irradiator provides underground location and storage of four neutron sources with total maximum neutrons flux of up to 1х109 cps.
The system remotely selects the required source and moves it to the expose position.
In the expose position, the source creates a wide non-collimated beam of fast neutrons by means of a shielding cone made of steal and borated polyethylene and a wide beam of neutrons by means of thermal sphere made of D2O according to ISO 8529-2.
Linear positioning system
The linear positioning system is designed to move the table with the tested instruments along three axes (X, Y, Z) and rotate it.
The table positioning in a specified coordinate is ensured by a special drive and logical programmable controller.
Remote control system
The control of all the system mechanisms is performed from the remote panel installed in the operator room. The panel is equipped with a touchscreen LCD display with 304 mm diagonal. The panel enables control in a semi-automatic mode or an adjustment mode and allows monitoring the mechanisms positions. The LCD indicates different text messages about the mechanisms operation and the results of temperature, humidity, and dose rate measurement.
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Radiation monitoring system
The system is designed to continuously monitor the radiation situation and consists of two smart gamma detectors and two neutron detectors. One pair of gamma and neutron detectors is installed on a wall in the irradiator room, another pair, in the operator room.
The control panel indicates current dose rate readings taken from each detector and warning messages about the excess of pre-set dose rate thresholds.
Video surveillance system
The system allows the operator to remotely monitor the readings of the tested instruments, position of the linear positioning system, and processes in the irradiator room.
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Alarm and interlock system
The system represents a complex of mechanisms and devices that, in combination with the control system, ensure the personnel protection from radiation.
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Optional system accessories are available on the customer request.
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Ambient dose equivalent rate (ADER) of neutron radiation, μSv/h
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3,5 – 3,4·104 | ||||||||
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Personal dose equivalent rate (PDER), μSv/h
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3,5 – 3,4·104 | ||||||||
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Density of fast neutrons flux, cps∙cm-2
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2,5 – 24,0·103 | ||||||||
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Density of thermal neutrons flux, cps∙cm-2
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1,0 – 5,6·103 | ||||||||
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Confidence limits of relative errors at 0.95 probability, no more
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Quantity of sources
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Maximum activity of sources during creation of wide non-collimated neutron beam
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1x109 | ||||||||
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Maximum activity of source, fast neutrons flux to solid angle of 4 π ср, cps
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Maximum dimensions of source, Øхh, mm
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35х45 | ||||||||
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Time of source transfer from storage/expose position to expose/storage position, no more, sec.
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15 | ||||||||
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Total flux of fast neutrons from sources placed in irradiator, no more, cps
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1x109 | ||||||||
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Radiation background level created by irradiator with maximum activity source in storage position at 1 m from irradiator surface, μSv/h, no more
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Irradiator dimensions and weight, no more
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Total weight of instruments installed on table, no more, kg
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70 | ||||||||
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Power consumption
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