The PEGASO system (Plastic dEtector for GAmma SOurce identification) is designed to automatically monitor the load of vehicles passing through its structure, and to detect any radioactive contamination due to the presence of gamma emitting radionuclide.
If a threshold is exceeded, the system immediately gives a warning to the operator through acoustic and luminous indications.
The system has a portal configuration, with the holding structures for the detectors placed at the sides of the passageway; the number of detection units changes according to the required sensitivity and to the expected vehicle type; in particular, a detection unit can be installed horizontally on the top of the passageway.
Each detection unit is composed of a high-efficiency plastic scintillator faced towards the passageway, together with a photomultiplier and the electronics for HV and signal processing.
The power supply and acquisition module provides power supply to the detection units and the position detectors, acquires the counts coming from the detectors, and indicates the system status through relays.
The continuous background monitoring, and its subtraction from the measurements, are automatically carried out.
To be compliant with specific logistic and radioprotection requirements, PEGASO system has several different versions each with a different set of principal components.
- Detector housing for Detection unit and position detectors. It is specifically built for outdoor installations, with high IP protection grade hinges, junctions and clamps. The housing is available in a vertical or horizontal configuration. The height of the support column and the position detectors orientation can be adjusted according to the installation requirements.
- Detection units PVT large-surface scintillators for gamma radioactivity measurements, installed at the sides of the portal passageway. The unit number, the distance between them, the height from the ground and the orientation are adjustable according to the installation site, the performance specifications and the type of vehicles.
- Power supply and acquisition module wall mounted or in a rack configuration. The module contains the power supplies, the acquisition and counting electronics, the relays for status signaling and the control Console connection interface. The distance for the connection to the control console can be up to 1 km.
- Control console composed of a PC, rack or tower configuration, with processing and management software PEGASO. It allows the operators to control the system.
- Typical configurations*:
- 2 vertical units configuration PEGASO 2UV
- PEGASO 4UH (4 horizontal units)
- PEGASO 3UH (bridge configuration)
- PEGASO 5UH
*download full tech spec to view the representation of each configuration
The system measures, as a function of time, the quantity of radiations coming from the vehicle passing through the portal. At the end, when the measurement area returns free, the software establishes whether the load is contaminated. If so, it gives an optical and acoustic signal. The contamination can be just suspected (pre-alarm) or firmly verified (alarm). The pre-alarm and alarm thresholds are indicated in sigma units (number of standard deviations) over the background value.
The counts temporal trend, and the spike’s position which determined the alarm, allow to identify the position of the source in the vehicle.
In addition to standard supply, the following options are available upon request:
- CDRB12810 – Calibrated 137Cs source for quality controls
- PEGASO-HOLD – Source holder for test and quality controls procedures
- PEGASO-PLATE – Plate detection and memorization kit: infrared illuminated camera for plate digital reading and archive
- PEGASO-CAM – Vehicle identification kit: camera and software to associate alarm events with images of the vehicle passing through
- PEGASO-SERV – Remote service via internet delivered by CAEN personnel
- ALU – Additional alarm unit with siren for remote signaling