No Arabic abstract
Every radiotherapy center has to be equipped with real-time beam monitoring devices. In 2008, the medical application group from the Laboratory of Corpuscular Physics (LPC Caen) developed an Ionization Chamber in collaboration with the company IBA (Ion Beam Applications). This monitoring device called IC2/3 was developed to be used in IBAs universal irradiation head for Pencil Beam Scanning (PBS). The objectives presented in this article are to characterize the IC2/3 monitor in the energy and ux ranges used in protontherapy. The equipment has been tested with an IBAs cyclotronable to deliver proton beams from 70 to 230 MeV. This beam monitoring device has been validated and is now installed at the Westdeutsches Protonentherapiezentrum Essen protontherapy center (WPE, Germany). The results obtained in both terms of spatial resolution and dose measurements are at least equal to the initials speci cations needed for PBS purposes. The detector measures the dose with a relative precision better than 1% in the range 0.5 Gy/min to 8 Gy/min while the spatial resolution is higher than 250 m. The technology has been patented and ve IC2/3 chambers were delivered to IBA. Nowadays, IBA produces the IC2/3 beam monitoring device as part of its Proteus 235 product
Currently, radiobiology experiments using heavy ions at GANIL(Grand Accelerateur National d Ions Lourds) are conducted under the supervision of the CIMAP (Center for research on Ions, MAterials and Photonics). In this context, a new beam monitoring equipment named DOSION has been developed. It allows to perform measurements of accurate fluence and dose maps in near real time for each biological sample irradiated. In this paper, we present the detection system, its design, performances, calibration protocol and measurements performed during radiobiology experiments. This setup is currently available for any radiobiology experiments if one wishes to correlate one s own sample analysis to state of the art dosimetric references.
A novel technique has been developed to build vessels for liquid xenon ionization detectors entirely out of ultra-clean fluoropolymer. We describe the advantages in terms of low radioactivity contamination, provide some details of the construction techniques, and show the energy resolution achieved with a prototype all-fluoropolymer ionization detector.
A beam tagging hodoscope prototype made of squared 1 mm$^2$ fibers arranged in two perpendicular planes and coupled to multi-anode photomultipliers has been studied using 65 MeV proton as well as 95 MeV/u $^{12}$C beams at various intensities. This hodoscope successfully provided 2D images of proton beams with a detection efficiency larger than 98 % with logical OR condition between the two fiber planes. The detection efficiency with a coincidence between the two planes is close to 75 % for beam intensities up to $sim1$ MHz. Moreover, the timing resolution is around 1.8 ns FWHM. Overall, the performances show that such a technology is viable for beam monitoring during hadrontherapy.
This paper presents the results of neutron flux measurements at two irradiation facilities of the TRIGA Mark II reactor at ENEA Casaccia Research Center, Italy. The goal of these measurements is to provide a complete characterization of neutron irradiation facilities for accurate and precise dose evaluation in radiation damage tests and, more generally, for all applications that need a good knowledge of neutron flux in terms of intensity, energy spectrum and spatial distribution. The neutron activation technique is used to measure the activation rates of several reactions, chosen so to cover the whole energy range of neutron flux spectrum. A multi-group neutron flux measurement is obtained through an unfolding algorithm based on a Bayesian statistical model. The obtained results prove that this experimental method allows to measure the total neutron flux within 2% statistical uncertainty, and to get at the same time a good description of its energy spectrum and spatial distribution.
A single channel, high precision ionization chamber has been built for monitoring the relative intensity of X-rays in the energy range above 5 keV. It can be used in experiments, such as EXAFS, where simultaneous high precision monitoring of the relative intensity during the actual experiment is required. In this paper the construction of the chamber and its performance during test measurements with an X-ray tube are presented.