GAMON-Diver

The GAMON-Diver is a highly efficient spectroscopic measurement system designed to perform for submerged radiometric measurement. The system can be deployed in multiple scenarios for gamma radionuclide identification in case of accident mitigation, first emergency response or can be installed as a long term monitoring device for sensitive underwater locations as access points.

The GAMON-Diver can be deployed in salt- and freshwater, dragged from a boat or stably mounted on a buoy for gamma spectroscopic measurements in real time. The hermetic case allows the instrument to operate at depths of 450 meters (45 ATM in water). The GAMON-Diver can identify gamma-emitting radionuclides and differentiate them based on the category they belong to, distinguishing between NORM, medical and industrial. The GAMON-Diver runs spectrum analysis algorithms that can perform simultaneous identification of multiple radiological sources and provides quantitative measurements in terms of dose and activity per radionuclide with its built in detector efficiency calibration. The user can select the isotopes to be identified from the library and adjust the thresholds of the isotope related alarms. The spectrum stabilization can be obtained with the identification of natural occurring radionuclides as the 40K.

The gamma spectrometer is composed by an inorganic scintillation crystal. The system integrates NaI(Tl) inorganic scintillator with configurable volume of 2”x2” or 3”x3”. Other high resolution scintillator detectors like CeBr3 or LaBr3(Ce) can be integrated on request. The options like NaI(Tl) or CeBr3 scintillators are best suited for low background measurements. Optional NaIL® can be installed, which gives the capability of detecting neutrons.

Signals from scintillation detector is pre-amplified and the pulse is digitized by a 12 bit 62.5 MHz fADC. Digital signal shaping and pulse height analysis is performed by a digital MCA with 2048 channels. The spectroscopy detector is configured to collect gamma interactions in the energy range from 30 keV to 3 MeV. It provides statistically accurate dose rate measurements starting from 1 nSv/h. The GAMON-Diver has RJ45 Ethernet and a WiFi wireless interface thanks to the surface junction box, where a GPS receiver is also installed.

The GAMON-Diver embedded ARM based CPU stores the data in an internal non-volatile memory of 8 GB. The spectrometer CPU runs a web interface to allow the user to easily configure the data acquisition and the isotopic analysis. The GUI of the software is a web interface reachable by a common browser. No apps or software installation is needed. Security level of the web interface can be configured by the user to avoid unauthorized setting changes.

The web interface shows the real time counting rate of the scintillator, the real time ambient dose equivalent rate, and the live spectrum by the scintillator is available on the dashboard. Counting and dosimetry trend of the last ten minutes are displayed in flow chart to help the user in the search of radiological dispersal device. Through the web interface the user can set the library of the radionuclides, set the alarm thresholds for each radionuclide and modify the measurement settings. The GAMON-Diver integrates a GPS sensor in the surface unit to provide georeferenced display of the measured quantities. Values are presented in a dynamic map both in real time acquisition and in the reports that are automatically generated. The GAMON-Diver can run an interface for attended operation modes suited for manned and unmanned surveys, for scuba divers or underwater ROV respectively. Also rugged IP65 tablets or laptop can be optionally provided, compliant with military standards for drop and vibration resistance (MIL-810G).

In alternative the system can acquire and display the data in a form suited for long term monitoring and provide alarms to a data monitoring centre. The web interface has a comprehensive dashboard with the status parameters of the monitoring station.