26 research outputs found
A compact gamma ray imager for oncology
No full textA variety of new techniques based on radiopharmaceuticals are showing a valid support for cancer detection and interventional procedures. Axillary lymph nodes status is the most important prognostic factor for determining breast cancer prognosis. The use of dedicated gamma cameras characterized by low costs and weight, could be easily transferred to detection for bioptical procedures. To this aim this paper presents a new detection system having two heads with 4 and 25 cm(2) Field of View (FOV) and 0.8 and 3.6 kg weight, respectively. This novel scintillation camera is based upon a compact Position Sensitive Photo Multiplier Tube (PSPMT) Hamamatsu R5900-C8 as individual or array assembled. The Hamamatsu R5900-C8 is a metal channel dynode PMT with a crossed wire anode. The overall dimensions are 28 x 28 mm(2) and 20 mm height. It was coupled to a CsI(T1) array of individual 3 x 3 x 3 mm 3 crystals. The measured intrinsic spatial resolution proved much better than the pixel size. A clinical image obtained from a breast phantom showed a 6 mm sized tumor. (C) 2002 Elsevier Science B.V. All rights reserved
A compact gamma ray imager for oncology
No full textA variety of new techniques based on radiopharmaceuticals are showing a valid support for cancer detection and interventional procedures. Axillary lymph nodes status is the most important prognostic factor for determining breast cancer prognosis. The use of dedicated gamma cameras characterized by low costs and weight, could be easily transferred to detection for bioptical procedures. To this aim this paper presents a new detection system having two heads with 4 and 25 cm(2) Field of View (FOV) and 0.8 and 3.6 kg weight, respectively. This novel scintillation camera is based upon a compact Position Sensitive Photo Multiplier Tube (PSPMT) Hamamatsu R5900-C8 as individual or array assembled. The Hamamatsu R5900-C8 is a metal channel dynode PMT with a crossed wire anode. The overall dimensions are 28 x 28 mm(2) and 20 mm height. It was coupled to a CsI(T1) array of individual 3 x 3 x 3 mm 3 crystals. The measured intrinsic spatial resolution proved much better than the pixel size. A clinical image obtained from a breast phantom showed a 6 mm sized tumor. (C) 2002 Elsevier Science B.V. All rights reserved
TAPIRO and TRIGA ENEA's Reactors as Neutron Source for Boron Neutron Capture Therapy
No full textReactors are currently seen as the most suitable type of neutron source for BNCT implementation, due to the high intensity of the flux they can provide. Neutron sources with epithermal spectrum are being considered for clinical use, because thermal neutrons have limited penetration depth and cannot be used for the treatment of deep pathologies.The preferred characteristics of the neutron beam are:- high epithermal flux intensity for reducing the irradiation time;- low/high energy neutrons component for sparing the healthy tissues;- low thermal neutron component which causes undue dose on surface tissues;- low gamma ray flux;- high forward component (current to flux ratio).In this work, beside a brief description of TRIGA characteristics for a BNCT activity, the design of a modification for the low-power fast-flux TAPIRO reactor to have an optimized epithermal flux is presented
A neutron tomographic system developed at the Rome research reactor
No full textA third-generation neutron tomographic system, mainly used for nondestructive evaluation on small hydrogenated samples, has been recently set up at the ENEA TRIGA RC II research reactor in Rome, Italy. This reactor operates at a nominal power of 1 MW and produces a thermal beam of about 2 × 105 cm-2 s-1 with a collimation ratio L/D of about 30. The object to be examined is viewed by a Thomson CSF neutron image intensifier coupled to a cooled CCD (Charge Coupled Device) camera equipped with a sensitive array of 192 × 165 pixels, each acting as an equivalent elementary neutron detector. The entire set of projections (usually 120) needed for the examination is acquired in about 90 min, as the system operates in a rotate-only configuration with parallel beam. The reconstruction software used is a development of the Donner Package for Reconstruction Tomography, specifically modified in order to deal with third-generation algorithms using the projection images produced by the CCD camera. At present, the total reconstruction time to obtain the full set of 165 slices of 192 × 192 pixels each is about 60 min on a standard Solbourne SPARC 4 multi-user workstation. © 1994
Design of Neutron Beams for Boron Neutron Capture Therapy in a Fast Reactor
No full textThe BNCT (Boron Neutron Capture Therapy) technique makes use of thermal or epithermal neutrons to irradiate tumors previously loaded with 10B.A thermal neutron beam can be very effective for the treatment of surface tumors such as skin melanoma, but it cannot be used for the treatment of deep pathologies, due to its limited penetration depth. Neutron sources providing an epithermal spectrum of energy ranging from 0.4 eV to 10 keV are being considered for clinical use for the treatment of deep-seated tumors.Reactors are currently seen as a suitable neutron source for BNCT implementation, due to the high intensity of the flux they can provide.The Tapiro reactor, that is located at the ENEA Casaccia Center near Rome, is a low-power fast-flux research reactor that can be useful employed for this application. It is a highly enriched uranium-235 fast neutron facility with a nominal power of 5 kW.In this work computer simulations and experimental arrangements were carried out for this reactor to obtain epithermal and thermal neutron beams for the application of BNCT in Italy in the framework of a specific research program.Using the MCNP-4B code, Monte Carlo calculations were carried out to determine the materials suitable for the design of the thermal and epithermal columns. Various arrangements of reflector and moderator materials have been investigated to achieve the desired experimental conditions
Thermal neutron radiation damage on light yield and attenuation length of scintillating fibres
No full textEvaluation of Hydrogen content in Metallic Samples by Neutron Computed Tomography
No full textNeutron radiography is currently a well-known technique, which is employed for non-destructive testing in a number of industrial and environmental applications [1, 2]. Originally developed for reactor fuel examinations, it is now effective in detecting small amounts of corrosion and infiltrations of hydrogen or light materials within thick metallic structures due to the particular behaviour of total neutron cross sections [3]. Nevertheless, improvements related to the development of tomographic systems, which allow far better imaging performances, have been achieved only in the last few years, as a consequence, primarily, of the production of large, charge coupled device (CCD) arrays [4]. Nowadays, neutron computed tomography is the technique most suited for the study of the distribution of hydrogen within metallic matrices. In this field, a series of experimental tests were carried out employing a set of nickel samples containing a H20-D20 solution in known percentages. It was possible, therefore, to obtain a calibration curve for the total neutron cross section vs. gray level in the reconstructed image. © 1995 IEEE
Thermal neutron radiation damage on light yield and attenuation length of scintillating fibres
No full textOrdinary and extraordinary complex refractive index of the lead tungstate (PbWO4) crystal
No full textNeutronic analyses of the trade demonstration facility
No full textThe TRiga Accelerator-Driven Experiment (TRADE), to be performed in the TRIGA reactor of the ENEA-Casaccia Centre in Italy, consists of the coupling of an external proton accelerator to a target to be installed in the central channel of the reactor scrammed to subcriticality. This pilot experiment, aimed at a global demonstration of the accelerator-driven system concept, is based on an original idea of C. Rubbia. The present paper reports the results of some neutronic analyses focused on the feasibility of TRADE. Results show that all relevant experiments (at different power levels in a wide range of subcriticalities) can be carried out with relatively limited modifications to the present TRIGA reactor
