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Author Martin-Luna, P.; Esperante, D.; Prieto, A.F.; Fuster-Martinez, N.; Rivas, I.G.; Gimeno, B.; Ginestar, D.; Gonzalez-Iglesias, D.; Hueso, J.L.; Llosa, G.; Martinez-Reviriego, P.; Meneses-Felipe, A.; Riera, J.; Regueiro, P.V.; Hueso-Gonzalez, F.
Title Simulation of electron transport and secondary emission in a photomultiplier tube and validation Type Journal Article
Year 2024 Publication Sensors and Actuators A-Physical Abbreviated Journal Sens. Actuator A-Phys.
Volume 365 Issue Pages 114859 - 10pp
Keywords Photomultiplier tube; Photodetector; Proton therapy; Monte Carlo simulation; Measurement
Abstract The electron amplification and transport within a photomultiplier tube (PMT) has been investigated by developing an in-house Monte Carlo simulation code. The secondary electron emission in the dynodes is implemented via an effective electron model and the Modified Vaughan's model, whereas the transport is computed with the Boris leapfrog algorithm. The PMT gain, rise time and transit time have been studied as a function of supply voltage and external magnetostatic field. A good agreement with experimental measurements using a Hamamatsu R13408-100 PMT was obtained. The simulations have been conducted following different treatments of the underlying geometry: three-dimensional, two-dimensional and intermediate (2.5D). The validity of these approaches is compared. The developed framework will help in understanding the behavior of PMTs under highly intense and irregular illumination or varying external magnetic fields, as in the case of prompt gamma-ray measurements during pencil-beam proton therapy; and aid in optimizing the design of voltage dividers with behavioral circuit models.
Address [Martin-Luna, Pablo; Esperante, Daniel; Fuster-Martinez, Nuria; Gimeno, Benito; Gonzalez-Iglesias, Daniel; Llosa, Gabriela; Martinez-Reviriego, Pablo; Meneses-Felipe, Alba; Hueso-Gonzalez, Fernando] CSIC UV, Inst Fis Corpuscular IFIC, C Catedrat Jose Beltran 2, Paterna 46980, Spain, Email: pablo.martin@uv.es
Corporate Author Thesis
Publisher (up) Elsevier Science Sa Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0924-4247 ISBN Medium
Area Expedition Conference
Notes WOS:001131902700001 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 5876
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Author Martinez-Reviriego, P.; Esperante, D.; Grudiev, A.; Gimeno, B.; Blanch, C.; Gonzalez-Iglesias, D.; Fuster-Martinez, N.; Martin-Luna, P.; Martinez, E.; Menendez, A.; Fuster, J.
Title Dielectric assist accelerating structures for compact linear accelerators of low energy particles in hadrontherapy treatments Type Journal Article
Year 2024 Publication Frontiers in Physics Abbreviated Journal Front. Physics
Volume 12 Issue Pages 1345237 - 12pp
Keywords dielectric assist accelerating (DAA) structures; radio frequency (RF); LINAC; hadrontherapy; standing wave
Abstract Dielectric Assist Accelerating (DAA) structures based on ultralow-loss ceramic are being studied as an alternative to conventional disk-loaded copper cavities. This accelerating structure consists of dielectric disks with irises arranged periodically in metallic structures working under the TM02-pi mode. In this paper, the numerical design of an S-band DAA structure for low beta particles, such as protons or carbon ions used for Hadrontherapy treatments, is shown. Four dielectric materials with different permittivity and loss tangent are studied as well as different particle velocities. Through optimization, a design that concentrates most of the RF power in the vacuum space near the beam axis is obtained, leading to a significant reduction of power loss on the metallic walls. This allows to fabricate cavities with an extremely high quality factor, over 100,000, and shunt impedance over 300 M omega/m at room temperature. During the numerical study, the design optimization has been improved by adjusting some of the cell parameters in order to both increase the shunt impedance and reduce the peak electric field in certain locations of the cavity, which can lead to instabilities in its normal functioning.
Address [Martinez-Reviriego, Pablo; Esperante, Daniel; Gimeno, Benito; Blanch, Cesar; Gonzalez-Iglesias, Daniel; Fuster-Martinez, Nuria; Martin-Luna, Pablo; Martinez, Eduardo; Menendez, Abraham; Fuster, Juan] CSIC Univ Valencia, Inst Fis Corpuscular IFIC, Paterna, Spain, Email: pablo.martinez.reviriego@ific.uv.es
Corporate Author Thesis
Publisher (up) Frontiers Media Sa Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2296-424x ISBN Medium
Area Expedition Conference
Notes WOS:001162373700001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5953
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Author Olivares Herrador, J.; Latina, A.; Aksoy, A.; Fuster Martinez, N.; Gimeno, B.; Esperante, D.
Title Implementation of the beam-loading effect in the tracking code RF-track based on a power-diffusive model Type Journal Article
Year 2024 Publication Frontiers in Physics Abbreviated Journal Front. Physics
Volume 12 Issue Pages 1348042 - 11pp
Keywords beam loading; LINAC; energy loss; tracking simulation; transient; high-intensity beam; CLEAR; gradient reduction
Abstract The need to achieve high energies in particle accelerators has led to the development of new accelerator technologies, resulting in higher beam intensities and more compact devices with stronger accelerating fields. In such scenarios, beam-loading effects occur, and intensity-dependent gradient reduction affects the accelerated beam as a consequence of its interaction with the surrounding cavity. In this study, a power-diffusive partial differential equation is derived to account for this effect. Its numerical resolution has been implemented in the tracking code RF-Track, allowing the simulation of apparatuses where transient beam loading plays an important role. Finally, measurements of this effect have been carried out in the CERN Linear Electron Accelerator for Research (CLEAR) facility at CERN, finding good agreement with the RF-Track simulations.
Address [Olivares Herrador, Javier; Latina, Andrea; Aksoy, Avni] CERN, Meyrin, Switzerland, Email: javier.olivares.herrador@cern.ch
Corporate Author Thesis
Publisher (up) Frontiers Media Sa Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2296-424x ISBN Medium
Area Expedition Conference
Notes WOS:001193122800001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 6019
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Author Vague, J.; Melgarejo, J.C.; Boria, V.E.; Guglielmi, M.; Moreno, R.; Reglero, M.; Mata, R.; Montero, I.; Gonzalez-Iglesias, D.; Gimeno, B.; Gomez, A.; Vegas, A.; Raboso, D.
Title Experimental Validation of Multipactor Effect for Ferrite Materials Used in L- and S-Band Nonreciprocal Microwave Components Type Journal Article
Year 2019 Publication IEEE Transactions on Microwave Theory and Techniques Abbreviated Journal IEEE Trans. Microw. Theory Tech.
Volume 67 Issue 6 Pages 2151-2161
Keywords Ferrites; ferromagnetic resonance; gadolinium-aluminum garnet; Holmium garnet; multipactor; space applications; wideband nonreciprocal devices
Abstract This paper reports on the experimental measurement of power threshold levels for the multipactor effect between samples of ferrite material typically used in the practical implementation of L-and S-band circulators and isolators. For this purposes, a new family of wideband, nonreciprocal rectangular waveguide structures loaded with ferrites has been designed with a full-wave electromagnetic simulation tool. The design also includes the required magnetostatic field biasing circuits. The multipactor breakdown power levels have also been predicted with an accurate electron tracking code using measured values for the secondary electron yield (SEY) coefficient. The measured results agree well with simulations, thereby fully validating the experimental campaign.
Address [Vague, Joaquin; Carlos Melgarejo, Juan; Boria, Vicente E.; Guglielmi, Marco; Reglero, Marta] Univ Politecn Valencia, iTEAM, Dept Comunicac, E-46022 Valencia, Spain, Email: jvague@dcom.upv.es;
Corporate Author Thesis
Publisher (up) Ieee-Inst Electrical Electronics Engineers Inc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0018-9480 ISBN Medium
Area Expedition Conference
Notes WOS:000470969100006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4056
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Author Berenguer, A.; Coves, A.; Gimeno, B.; Bronchalo, E.; Boria, V.E.
Title Experimental Study of the Multipactor Effect in a Partially Dielectric-Loaded Rectangular Waveguide Type Journal Article
Year 2019 Publication IEEE Microwave and Wireless Components Letters Abbreviated Journal IEEE Microw. Wirel. Compon. Lett.
Volume 29 Issue 9 Pages 595-597
Keywords Dielectric; multipactor effect; rectangular waveguide; RF breakdown; Secondary Electron Yield (SEY); waveguide transformer
Abstract This letter presents the experimental study of the multipactor threshold in a partially dielectric-loaded rectangular waveguide, whose results validate a multipactor model recently developed by the authors, which includes the charge distribution appearing on the dielectric surface during the multipactor discharge. First, the variation of the multipactor RF voltage threshold has been theoretically analyzed in different waveguide configurations: in an empty waveguide, and also in the cases of a one-sided and two-sided dielectric-loaded waveguides. To reach this aim, an in-house Monte Carlo simulation tool has been developed. The Secondary Electron Yield (SEY) of the metallic and dielectric materials used in the numerical simulations have been measured experimentally. Finally, an aluminum WR-75 symmetric E-plane rectangular waveguide transformer has been designed and fabricated, in which several multipaction tests have been carried out to validate the in-house software tool, demonstrating an excellent agreement between the simulation results and the experimental data.
Address [Berenguer, Andres; Coves, Angela; Bronchalo, Enrique] Univ Miguel Hernandez Elche, Dept Commun Engn, Elche 03202, Spain, Email: angela.coves@umh.es
Corporate Author Thesis
Publisher (up) Ieee-Inst Electrical Electronics Engineers Inc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1531-1309 ISBN Medium
Area Expedition Conference
Notes WOS:000489754400009 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 4170
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