The objective of the "TELEMAN 22" project was to develop a system to capture the image of a radioactive source in hazardous industrial environments. The system was intended to be of small size, compact and portable enough to be installed aboard a vehicle. The prototype was to be divided in two parts: the detection head and the processing electronics. The first was to contain the room temperature position sensitive detector, its front-end electronics, and a mask acting as a radiation lens. The second unit was to house the computer and high level processing units to form the image of the source. Communication channels to interchange information with the external world were to be provided.
A system is being developed to capture the image of a radioactive source in hazardous industrial environments.
Demonstration of the feasibility of such equipment has been successfully achieved. The system has been able to reconstruct accurately (within the expected resolution) the position of point emitters located inside its field of view. Single and composed sources have been imaged, demonstrating that the gamma camera can locate more than 1 source within its field of view. Angular resolution between near sources, as well as the total field of view and zoom capability have been experimentally determined, being in good agreement with the design specifications. Finally, the minimum exposure (in Rads) needed to form an image has been explored for several geometries and energies.
The basic output of TM22 has been a laboratory prototype of the gamma-camera. This can be used in practical applications, although further effort should be made to "industrialise" the prototype. Once a final device is obtained, its utility is potentially high in the Nuclear Sector. CIEMAT and HARWELL have the technical skills to manufacture the camera, while AMYS and ENSA have expertise to operate it in a real environment. Exploitation will also be assured through further development and integration into the TELEMAN TM45 - IMPACT and TM50 - MESSINA research machine projects.
Work to be done
The work was to be divided in three main parts: the development of the detection head with its electronics, the definition of the algorithms to form the image of sources located in the proximity of the system and the communication protocols with the external world. The first part of the work was to be the fabrication and verification of a micro-detector for position resolution and the analog electronics associated with it; the output was to be the intensity map across the array of pixels. The second part, the image sub-system, was to use this intensity information and perform a correlation process with the mask transfer function (the " optical" lens) to determine the image of the source. The final part of the work was to relate to the definition and implementation of standard protocols to interchange the radiation image information and to integrate this sensor data into a network with other sensor responses.
The whole system, especially the detection head that was going to be near the radiation source, had to be sufficiently tolerant to radiation doses. Thus, the test strategy was to be focused on two features: the image quality (resolution, intensity....) and the radiation damage tolerance. The first was to be tested in a calibration station by looking at the system response to a known source distribution. The second was to be tested by irradiating the system under controlled high doses.
Funding SchemeCSC - Cost-sharing contracts
OX11 0RA Didcot - Oxfordshire