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Author |
Borja-Lloret, M.; Barrientos, L.; Bernabeu, J.; Lacasta, C.; Muñoz, E.; Ros, A.; Roser, J.; Viegas, R.; Llosa, G. |
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Title |
Influence of the background in Compton camera images for proton therapy treatment monitoring |
Type |
Journal Article |
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Year |
2023 |
Publication |
Physics in Medicine and Biology |
Abbreviated Journal |
Phys. Med. Biol. |
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Volume |
68 |
Issue |
14 |
Pages |
144001 - 16pp |
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Keywords |
Compton imaging; Compton camera; proton therapy; treatment monitoring; Monte Carlo simulation; image reconstruction; background |
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Abstract |
Objective. Background events are one of the most relevant contributions to image degradation in Compton camera imaging for hadron therapy treatment monitoring. A study of the background and its contribution to image degradation is important to define future strategies to reduce the background in the system. Approach. In this simulation study, the percentage of different kinds of events and their contribution to the reconstructed image in a two-layer Compton camera have been evaluated. To this end, GATE v8.2 simulations of a proton beam impinging on a PMMA phantom have been carried out, for different proton beam energies and at different beam intensities. Main results. For a simulated Compton camera made of Lanthanum (III) Bromide monolithic crystals, coincidences caused by neutrons arriving from the phantom are the most common type of background produced by secondary radiations in the Compton camera, causing between 13% and 33% of the detected coincidences, depending on the beam energy. Results also show that random coincidences are a significant cause of image degradation at high beam intensities, and their influence in the reconstructed images is studied for values of the time coincidence windows from 500 ps to 100 ns. Significance. Results indicate the timing capabilities required to retrieve the fall-off position with good precision. Still, the noise observed in the image when no randoms are considered make us consider further background rejection methods. |
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Address |
[Borja-Lloret, M.; Barrientos, L.; Bernabeu, J.; Lacasta, C.; Munoz, E.; Ros, A.; Roser, J.; Viegas, R.; Llosa, G.] Inst Fis Corpuscular IFIC, CSIC UV, Valencia, Spain, Email: Marina.Borja@csic.es |
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Publisher |
IOP Publishing Ltd |
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Language |
English |
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ISSN |
0031-9155 |
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Notes |
WOS:001022671300001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration  |
no |
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Call Number |
IFIC @ pastor @ |
Serial |
5571 |
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Author |
Real, D.; Calvo, D. |
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Title |
Silicon Photomultipliers for Neutrino Telescopes |
Type |
Journal Article |
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Year |
2023 |
Publication |
Universe |
Abbreviated Journal |
Universe |
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Volume |
9 |
Issue |
7 |
Pages |
326 - 14pp |
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Keywords |
silicon photomultipliers; neutrino telescopes; time to digital converters; electronics acquisition |
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Abstract |
Neutrino astronomy has opened a new window to the extreme Universe, entering into a fruitful era built upon the success of neutrino telescopes, which have already given a new step forward in this novel and growing field by the first observation of steady point-like sources already achieved by IceCube. Neutrino telescopes equipped with Silicon PhotoMultipliers (SiPMs) will significantly increase in number, because of their excellent time resolution and the angular resolution, and will be in better condition to detect more steady sources as well as the unexpected. The use of SiPMs represents a challenge to the acquisition electronics because of the fast signals as well as the high levels of dark noise produced by SiPMs. The acquisition electronics need to include a noise rejection scheme by implementing a coincidence filter between channels. This work discusses the advantages and disadvantages of using SiPMs for the next generation of neutrino telescopes, focusing on the possible developments that could help for their adoption in the near future. |
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Address |
[Real, Diego; Calvo, David] Univ Valencia, Inst Fis Corpuscular, CSIC, IFIC, C Catedrat Jose Beltran 2, Valencia 46980, Spain, Email: real@ific.uv.es |
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Mdpi |
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English |
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Notes |
WOS:001038900800001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ pastor @ |
Serial |
5593 |
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Author |
Garcia-Barcelo, J.M.; Melcon, A.A.; Diaz-Morcillo, A.; Gimeno, B.; Lozano-Guerrero, A.J.; Monzi-Cabrera, J.; Navarro-Madrid, J.R.; Navarro, P. |
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Title |
Methods and restrictions to increase the volume of resonant rectangular-section haloscopes for detecting dark matter axions |
Type |
Journal Article |
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Year |
2023 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
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Volume |
08 |
Issue |
8 |
Pages |
098 - 37pp |
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Keywords |
Axions and ALPs; Particle Nature of Dark Matter |
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Abstract |
Haloscopes are resonant cavities that serve as detectors of dark matter axions when they are immersed in a strong static magnetic field. In order to increase the volume and improve space compatibility with dipole or solenoid magnets for axion searches, various haloscope design techniques for rectangular geometries are discussed in this study. The volume limits of two types of haloscopes are explored: those based on single cavities and those based on multicavities. In both cases, possibilities for increasing the volume of long and/or tall structures are presented. For multicavities, 1D geometries are explored to optimise the space in the magnets. Also, 2D and 3D geometries are introduced as a first step in laying the foundations for the development of these kinds of topologies. The results prove the usefulness of the developed methods, evidencing the ample room for improvement in rectangular haloscope designs nowadays. A factor of three orders of magnitude improvement in volume compared with a single cavity based on the WR-90 standard waveguide is obtained with the design of a long and tall single cavity. Similar procedures have been applied for long and tall multicavities. Experimental measurements are shown for prototypes based on tall multicavities and 2D structures, demonstrating the feasibility of using these types of geometries to increase the volume of real haloscopes. |
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Address |
[Garcia-Barcelo, J. M.; Melcon, A. Alvarez; Diaz-Morcillo, A.; Lozano-Guerrero, A. J.; Monzo-Cabrera, J.; Navarro-Madrid, J. R.; Navarro, P.] Univ Politecn Cartagena, Dept Tecnol Informac & Comun, Pl Hosp 1, Cartagena 30302, Spain, Email: josemaria.garcia@upct.es; |
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Corporate Author |
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Publisher |
Springer |
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English |
Summary Language |
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ISSN |
1029-8479 |
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Notes |
WOS:001050076700002 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ pastor @ |
Serial |
5611 |
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Author |
Real, D.; Calvo, D.; Zornoza, J.D.; Manzaneda, M. |
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Title |
White Rabbit Expansion Board: Design, Architecture, and Signal Integrity Simulations |
Type |
Journal Article |
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Year |
2023 |
Publication |
Electronics |
Abbreviated Journal |
Electronics |
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Volume |
12 |
Issue |
16 |
Pages |
3394 - 16pp |
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Keywords |
subnanosecond synchronization; White Rabbit; IEEE Std 1588-2019; virtual prototyping |
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Abstract |
The White Rabbit protocol allows synchronization and communication via an optical link in an integrated, modular, and scalable manner. It provides a solution to those applications that have very demanding requirements in terms of synchronization. Field-programmable gate arrays are used to implement the protocol; additionally, special hardware is needed to provide the necessary clock signals used by the dual-mixer time difference for precise phase measurement. In the present work, an expansion board that allows for White Rabbit functionality is presented. The expansion board contains the oscillators required by the White Rabbit protocol, one running at 125 MHz and another at 124.922 MHZ. The architecture of this board includes two oscillator systems for tests and comparison. One is based on VCOs and another on crystal oscillators running at the desired frequencies. In addition, it incorporates a temperature sensor, from where the medium access control address is extracted, an electrically erasable programmable read-only memory, a pulse-per-second output, and a USB UART to access the White Rabbit IP core at the field-programmable gate array. Finally, to ensure the quality of the layout design and guarantee the level of synchronization desired, the results of the power and signal integrity simulations are also presented. |
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Address |
[Real, Diego; Calvo, David; de Dios Zornoza, Juan; Manzaneda, Mario] Univ Valencia, IFIC Inst Fis Corpuscular, CSIC, C Catedrat Jose Beltran 2, Paterna 46980, Spain, Email: real@ific.uv.es; |
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Publisher |
Mdpi |
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English |
Summary Language |
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Notes |
WOS:001056236300001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ pastor @ |
Serial |
5628 |
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Author |
Cosme, C.; Figueroa, D.G.; Loayza, N. |
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Title |
Gravitational wave production from preheating with trilinear interactions |
Type |
Journal Article |
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Year |
2023 |
Publication |
Journal of Cosmology and Astroparticle Physics |
Abbreviated Journal |
J. Cosmol. Astropart. Phys. |
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Volume |
05 |
Issue |
5 |
Pages |
023 - 30pp |
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Keywords |
physics of the early universe; primordial gravitational waves (theory); gravita-tional waves; sources; particle physics-cosmology connection |
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Abstract |
We investigate the production of gravitational waves (GWs) during preheating with monomial/polynomial inflationary potentials, considering a trilinear coupling & phi;x2 between a singlet inflaton & phi; and a daughter scalar field x. For sufficiently large couplings, the trilinear interaction leads to an exponential production of x particles and, as a result, a large stochastic GW background (SGWB) is generated throughout the process. We study the linear and non-linear dynamics of preheating with lattice simulations, following the production of GWs through all relevant stages. We find that large couplings lead to SGWBs with amplitudes today that can reach up to h2 �(0) GW <^> 5 & BULL; 10-9. These backgrounds are however peaked at high frequencies fp > 5 & BULL; 106 Hz, which makes them undetectable by current/planned GW observatories. As the amount of GWs produced is in any case remarkable, we discuss the prospects for probing the SGWB indirectly by using constraints on the effective number of relativistic species in the universe Neff. |
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Address |
[Cosme, Catarina; Figueroa, Daniel G.; Loayza, Nicolas] Univ Valencia CSIC, Inst Fis Corpuscular IFIC, Parc Cientif UV,C-Catedrat Jose Beltran 2, E-46980 Paterna, Spain, Email: catarina.cosme@ific.uv.es; |
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Corporate Author |
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Thesis |
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Publisher |
IOP Publishing Ltd |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1475-7516 |
ISBN |
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Conference |
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Notes |
WOS:001038638500007 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ pastor @ |
Serial |
5660 |
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| Permanent link to this record |
