Project NEMO (Naval Examination by Muon Observation)
We are witnessing an alarming increase of the number of terrorist attacks all around the globe. Almost every week the media reports attacks carried out using fire weapons and explosives. Taking into account the impressive level of planning needed to carry out some of these actions, we have to conclude that the terrorists are capable of managing the logistics needed to perform attacks using nuclear materials or weapons. Nuclear materials can easily be concealed in large ships. They have the capability of easily transporting the huge weight needed for shielding radioactive materials. Increasing the security measures in international harbours is absolutely necessary, and can be accomplished by using a new detection system.
The method proposed is based on the detection and analysis of the cosmic muon flux. Apart from radioactive ores, high density materials (uranium, lead – used for radiation shielding etc.) will also cause a decrease in the directional muon flux. The detection system will be submerged underneath the ship that will be scanned, being able to locate illegal radioactive materials without exposing any personnel to radiation or contamination. Correlated with simulations based on the known configuration of the ship scanned, the data provided by the detection system will provide the location and dimensions of the undeclared material transported.
The Research Team
Dr. Habil. Bogdan Mitrica – Project Leader
Dr. Romul-Mircea Margineanu – Senior Researcher
Dr. Denis Stanca – Senior Researcher
Toma Stefan Mosu – Ph.D Student
Dr. Dana-Elena Dumitriu – Senior Researcher
Dr. Iliana-Magdalena Brancus – Senior Researcher
Dr. Alexandra Saftoiu – Senior Researcher
Alexandru Gherghel-Lascu – Ph.D. Student
Alexandru Balaceanu – Ph.D. Student
Mihai Niculescu-Oglinzanu – Ph.D. Student
Andreea Munteanu – Tehnician
Gherghina Stan – Tehnician
The method of project implementation is comprised of two main stages, each with its related activities:
Stage 1. Simulation of the detector response and laboratory tests and development of the experimental configuration
Activity 1.1. Simulation of detector response and efficiency
Activity 1.2. Development and testing of the electronics and DAQ
Activity 1.3. Design of the detection system
Stage 2. Testing and validation of the device
Activity 2.1. Testing and validation of the device
Currently, we finished both Stage 1 and Stage 2 of the project.
Proiectul NEMO isi propune sa reduca riscurile generate de traficul de materiale radioactive prin imbunatatirea masurilor de securitate din porturile maritime si fluviale. In acest scop, un sistem de detectie a fost proiectat si dezvoltat.
Metoda propusa are la baza tomografia miuonica, mai exact scanarea obiectelor prin masurarea variatiei fluxului directional al miuonilor cosmici la intersectia cu acestea. Sistemul de detectie va fi plasat in mediul subacvatic, sub navele ce vor fi scanate.
Materialele radioactive, dar si containerele de plumb in care acestea sunt transportate, avand o densitate mare comparativ cu cea a materialelor uzuale, intalnite ca marfuri sau cu a materialelor din care sunt confectionate vapoarele, vor cauza o scadere a fluxului directional de miuoni inregistrat de detector pe directia obiectelor respective. Din datele colectate vor fi reconstruite dimensiunile materialelor nedeclarate si pozitia acestora.
Acest detector este o imbunatatire a tehnologiei deja disponibile si functionale in IFIN-HH, cum ar fi detectorul mobil pentru masurarea fluxului miuonilor, detectorul WILLI, sistemul de detectie WILLI-AIR, detectorul SiRO, etc.
Dispozitivul experimental este proiectat ca fiind alcatuit din doua suprafete active, fiecare fiind capabila sa detecteze pozitia interactiei cu particula incidenta, realizandu-se astfel masurarea directionala a fluxului miuonilor cosmici. Fiecare suprafata activa va fi alcatuita din doua straturi de bare scintilatoare, plasate in cruce, putandu-se astfel determina coordonatele X-Y ale punctului de interactie cu particula incidenta. Barele vor fi acoperite cu un material izolator pentru a elimina crosstalk-ul optic. Folosirea a doua astfel de suprafete active (4 straturi de bare scintilatoare), va face posibila reconstructia traiectoriei miuonilor. Fotonii rezultati in barele scintilatoare vor fi colectati prin intermediul unor fibre optice schimbatoare de ghid de unda si transmise la un micro-fotomultiplicator cu 64 de canale pozitionat la unul dintre capete.
In plus, pentru a putea functiona in mediul subacvatic, o linie de alimentare catre suprafata a fost dezvoltata, fiind de asemenea investigata posibilitatea folosirii bateriilor. Se va urmari reducerea consumului de electricitate cat mai mult cu putinta. De asemenea, pentru a putea fi implementat pe scara larga ca sistem de siguranta pentru scanarea navelor in porturi, pretul reprezinta un alt factor important de luat in calcul.
The NEMO project proposes to reduce the risks generated by the trafficking of radioactive materials, through improving of the security measures of the maritime and fluvial ports. In order to achieve this goal, a detection system was designed and developed. The proposed method is based on muon tomography, precisely the scanning of objects through cosmic muons directional flux variation measurement when it intersects with them. The detection system will be placed in underwater medium, under the ships that will be scanned.
The radioactive materials, but also the lead containers in which they are transported, having a great density compared with the usual cargo freight or the fairing/hull of the ships, will cause a drop of the directional muon flux recorded by the detector in the respective objects direction. From the collected data there will be a reconstruction of the undeclared materials and their position.
This detector is an improving of the current available technology in IFIN-HH, like the mobile detector for the muon flux measurement, the WILLI detector, the WILLI-AIR detection system, SiRO detector, etc.
The experimental device is developed to be made of two active surfaces, each being capable to detect the position of the incident particle interaction, in this way the directional cosmic muon flux measurement is realised. Each active surface will be made of two scintillator bars placed in a cross position, in this way being possible to determinate the X-Y coordinates of the interaction point with the incident particle. The bars will be covered with an insulator material in order to eliminate the optic cross-talk. Using two active surfaces like these (4 layers of scintillator bars) will make the muon trajectory reconstruction possible. The resulted photons in the scintillator bars will be collected through wave guide changing optical fibers and transmitted to a micro-photomultiplier with 64 channels, positioned at one of the ends.
Additionally, to work in an underwater medium, a power supply line to the surface has been developed, also being investigated the possibility of battery usage. Also, in order to be implemented on a large scale as a security system for ship scanning in harbors, with the price representing another important factor.