Search

Your search keyword '"Nichelatti E"' showing total 304 results
Start Over Author "Nichelatti E"
304 results on '"Nichelatti E"'

3. Approximate calculation of backpropagated energy spectrum for a proton beam.

Author

Nichelatti, E., Piccinini, M., Ampollini, A., Astorino, M. D., Bazzano, G., Nenzi, P., Surrenti, V., Trinca, E., and Ronsivalle, C.

Subjects
*CRYSTAL lattices, *LITHIUM fluoride, *PROTONS, *PHOTOLUMINESCENCE, *CRYSTALS, *PROTON beams, *LINEAR accelerators
Abstract

In certain experimental setups used for proton irradiations at the TOP-IMPLART linear accelerator at the ENEA Frascati Center, the energy spectrum of the proton beam is measured at the end of a propagation path, which includes transmission through different materials, such as air, windows, slabs, etc. In this paper, we develop and test an approximate mathematical method to calculate the energy spectrum at the accelerator exit from such a measured transmitted spectrum. In the first experimental test application, the spectrum measurement exploits the visible photoluminescence of F 2 and F 3 + color centers generated in lithium fluoride crystals by the interaction of the crystal lattice with protons. In the second test application, a simulated measurement of a propagated energy spectrum along a transport line is considered. In principle, the proposed method is applicable to the energy spectra of proton beams measured in any manner. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

12. VUV-Vis optical characterization of Tetraphenyl-butadiene films on glass and specular reflector substrates from room to liquid Argon temperature

Author

Francini, R., Montereali, R. M., Nichelatti, E., Vincenti, M. A., Canci, N., Segreto, E., Cavanna, F., Di Pompeo, F., Carbonara, F., Fiorillo, G., and Perfetto, F.

Subjects
Physics - Instrumentation and Detectors
Abstract

The use of efficient wavelength-shifters from the vacuum-ultraviolet to the photosensor's range of sensitivity is a key feature in detectors for Dark Matter search and neutrino physics based on liquid argon scintillation detection. Thin film of Tetraphenyl-butadiene (TPB) deposited onto the surface delimiting the active volume of the detector and/or onto the photosensor optical window is the most common solution in current and planned experiments. Detector design and response can be evaluated and correctly simulated only when the properties of the optical system in use (TPB film + substrate) are fully understood. Characterization of the optical system requires specific, sometimes sophisticated optical methodologies. In this paper the main features of TPB coatings on different, commonly used substrates is reported, as a result of two independent campaigns of measurements at the specialized optical metrology labs of ENEA and University of Tor Vergata. Measured features include TPB emission spectra with lineshape and relative intensity variation recorded as a function of the film thickness and for the first time down to LAr temperature, as well as optical reflectance and transmittance spectra of the TPB coated substrates in the wavelength range of the TPB emission.

Published
2013
Full Text
View/download PDF

16. Optical Characterization of Organic Light-Emitting Thin Films in the Ultraviolet and Visible Spectral Ranges

Author

Montereali, R. M., Vincenti, M. A., Nichelatti, E., Di Pompeo, F., Segreto, E., Canci, N., and Cavanna, F.

Subjects
Physics - Instrumentation and Detectors, Physics - Optics
Abstract

The spectrophotometric characterization of high efficiency, optically-active samples such as light-emitting organic bulks and thin films can be problematic because their broad-band luminescence is detected together with the monochromatic transmitted and reflected signals, hence perturbing measurements of optical transmittance and reflectance at wavelengths within the photoexcitation band. As a matter of fact, most commercial spectrophotometers apply spectral filtering before the light beam reaches the sample, not after it. In this Report, we introduce and discuss the method we have developed to correct photometric spectra that are perturbed by photoluminescence., Comment: 25 pages, 11 figures

Published
2012

17. Advanced spectroscopic investigation of colour centres in LiF crystals irradiated with monochromatic hard x-rays

Author

Vincenti, M A, primary, Montereali, R M, additional, Bonfigli, F, additional, Nichelatti, E, additional, Nigro, V, additional, Piccinini, M, additional, Koenig, M, additional, Mabey, P, additional, Rigon, G, additional, Dabrowski, H J, additional, Benkadoum, Y, additional, Mercere, P, additional, Da Silva, P, additional, Pikuz, T, additional, Ozaki, N, additional, Makarov, S, additional, Pikuz, S, additional, and Albertazzi, B, additional

Published
2024
Full Text
View/download PDF

20. Photoluminescent Bragg curves in lithium fluoride thin films on silicon substrates irradiated with a 35 MeV proton beam.

Author

Nichelatti, E., Nigro, V., Piccinini, M., Vincenti, M. A., Ampollini, A., Picardi, L., Ronsivalle, C., and Montereali, R. M.

Subjects
*SILICON films, *PROTON beams, *THIN films, *LITHIUM fluoride, *MONTE Carlo method, *MULTIPLE scattering (Physics)
Abstract

Proton irradiation of lithium fluoride (LiF) crystals and thin films causes the formation of electronic defects, known as color centers, in the crystal lattice, some of which show photoluminescence in the visible range under blue-light excitation. With a suitable irradiation geometry, the energy density that protons deposit in the material can be recorded as a spatial distribution of these light-emitting color centers, from which a luminous replica of the proton Bragg curve can be thereafter extracted and analyzed in a fluorescence microscope. In this paper, the cases of two LiF thin films deposited on silicon substrates and of a LiF crystal, all of them transversally irradiated with a nominal 35 MeV proton beam, are considered. A comparison of the measured photoluminescent Bragg curves with Monte Carlo simulations demonstrates (i) that the Bragg peaks in the films are located at the very same positions that would be expected in the underlying silicon substrates rather than in LiF and (ii) that an even small grazing angle of the impinging proton beam is able to significantly modify the shape of the Bragg curve in the films. Both of these findings are ascribed to the effects of multiple Coulomb scattering in both the film and the substrate. The coincidence of the Bragg peak positions with those expected in the silicon substrates and the possibility of visualizing such peaks in the Bragg curves stored as latent fluorescence images in the LiF films allow one to regard them as information transducers for proton beam diagnostics and dosimetry. [ABSTRACT FROM AUTHOR]

Published
2022
Full Text
View/download PDF

24. Optical characterization of lithium fluoride thin-film imaging detectors for monochromatic hard X-rays

Author

Vincenti, M.A., primary, Montereali, R.M., additional, Nichelatti, E., additional, Nigro, V., additional, Piccinini, M., additional, Koenig, M., additional, Mabey, P., additional, Rigon, G., additional, Dabrowski, H.J., additional, Benkadoum, Y., additional, Mercere, P., additional, Da Silva, P., additional, Pikuz, T., additional, Ozaki, N., additional, Makarov, S., additional, Pikuz, S., additional, and Albertazzi, B., additional

Published
2023
Full Text
View/download PDF

31. Optimization of the theoretical dose distribution in the 'Spread out Bragg Peak' (SOBP) region in proton therapy by means of semi-analytical techniques

Author

Nichelatti E., Ronsivalle C., Picardi L., Montereali R. M., Nichelatti, E., Ronsivalle, C., Picardi, L., and Montereali, R. M.

Abstract

Proton therapy uses proton beams to destroy cancer cells. Since the energy deposition of protons peaks at the end of the trajectory (Bragg peak), healthy tissues close to the target are partially spared. In clinical practice, beams of different energies are composed to obtain a broadened peak (SOBP, Spread Out Bragg Peak) to treat the entire lesion region in a uniform manner. In the framework of the TOP-IMPLART project (linear accelerator for proton therapy under construction at ENEA-Frascati), we present a semi-analytical method that allows to optimize SOBP uniformity for two different energy-modulation techniques, passive and active.

Published
2021

41. Beam characterization methods at the TOP-IMPLART proton linear accelerator: an application to space components qualification

Author

Bazzano, G., primary, Ampollini, A., additional, Cisbani, E., additional, De Angelis, C., additional, Della Monaca, S., additional, Nenzi, P., additional, Nichelatti, E., additional, Palmerini, G.B., additional, Picardi, L., additional, Piccinini, M., additional, Ronsivalle, C., additional, and Sabatini, M., additional

Published
2021
Full Text
View/download PDF

44. Imaging detectors based on photoluminescence of radiation-induced defects in lithium fluoride for XFEL beam monitoring

Author

Bonfigli F., Capotondi F., Cricenti A., Giannessi L., Kiskinova M., Luce M., Mahne N., Manfredda M., Montereali R. M., Nichelatti E., Pedersoli E., Raimondi L., Vincenti M. A., Zangrando M., Bonfigli, F., Capotondi, F., Cricenti, A., Giannessi, L., Kiskinova, M., Luce, M., Mahne, N., Manfredda, M., Montereali, R. M., Nichelatti, E., Pedersoli, E., Raimondi, L., Vincenti, M. A., and Zangrando, M.

Subjects
LiF, Physics::Optics, photoluminescence, defects
Abstract

Lithium fluoride (LiF) films and crystals are versatile X-ray imaging detectors based on the optical reading of visible photoluminescence from radiation-induced electronic defects. Distinctive features of these detectors are their high spatial resolution across a large field of view, wide dynamic range and insensitivity to ambient light. These peculiarities of LiF detectors appear to be promising for monitoring the spatial intensity distribution of ultra-short, ultra-high pulses of the EUV-X-ray Free Electron Laser (XFEL) and could be exploited for coherent diffraction imaging experiments.

Published
2019
Full Text
View/download PDF

46. Optical characterization of low-energy electron-beam-colored LiF crystals by spectral transmittance measurements

Author

Montecchi, M., Nichelatti, E., Mancini, A., and Montereali, R.M.

Subjects
Electron beams -- Research, Lithium alloys -- Research, Optical waveguides -- Research, Physics
Abstract

The stable formation of color centers in a LiF crystal surface layer irradiated by low-energy electrons influences its complex refractive index. To estimate the dispersion curves of colored LiF from a single optical transmittance measurement, a modified dipole-electromagnetic field interaction model was used. The benefits of the characterization method consists in the evaluation of the contribution of the active defects to the refractive index modifications.

Published
1999

50. Transverse modes in laser cavities terminating in reflective multipass interferometers

Author

Nichelatti, E. and Salvetti, G.

Subjects
Laser interferometers -- Evaluation, Laser beams -- Analysis, Lasers -- Resonators, Astronomy, Physics
Abstract

The effect of reflective multipass interferometers on the transverse modes of laser cavities equipped with these devices is investigated. We demonstrate, both theoretically and experimentally in a pulsed C[O.sub.2] laser, how information on the characteristics of these modes can be directly derived by simply describing these cavities in terms of suitable equivalent geometric parameters. We also discuss and explain the transverse-mode selective properties of these multimirror cavities.

Published
1995

Catalog

Books, media, physical & digital resources
See catalog results