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B. Naranjo

Publications and source records attributed to B. Naranjo.

15 recordsLinked to original sources
arXiv2026

Generalized Theory of Blowout-Regime Plasma Wakefields via a Lagrangian Formulation

The blowout regime of plasma wakefield acceleration is a strongly nonlinear plasma response in which an intense relativistic beam or laser pulse expels plasma electrons forming a nearly uniform ion column. Existing self-consistent theories describe this structure primarily in the axisymmetric limit, reducing the bubble dynamics to a single radial degree of freedom. This restriction is inadequate for flat beams with highly asymmetric transverse emittances, as required in future linear colliders to control luminosity and beamstrahlung. Using a reduced Lagrangian formulation, we generalize the existing theory beyond axisymmetry and derive a coupled system of equations governing the wake potential driven by an asymmetric beam. This theory self-consistently predicts the focusing fields and their variation along the co-moving coordinate, as well as the accelerating field and its transverse nonuniformity. The resulting theoretical predictions are benchmarked against particle-in-cell simulations, demonstrating the theory's ability to describe and interpret wakefields driven by nonaxisymmetric sources.

physics.acc-ph↗
arXiv2024

Reconstructing Gamma-ray Energy Distributions from PEDRO Pair Spectrometer Data

Photons emitted from high-energy electron beam interactions with high-field systems, such as the upcoming FACET-II experiments at SLAC National Accelerator Laboratory, may provide deep insight into the electron beam's underlying dynamics at the interaction point. With high-energy photons being utilized to generate electron-positron pairs in a novel spectrometer, there remains a key problem of interpreting the spectrometer's raw data to determine the energy distribution of the incoming photons. This paper uses data from simulations of the primary radiation emitted from electron interactions with a high-field, short-pulse laser to determine optimally reliable methods of reconstructing the measured photon energy distributions. For these measurements, recovering the emitted 10 MeV to 10 GeV photon energy spectra from the pair spectrometer currently being commissioned requires testing multiple methods to finalize a pipeline from the spectrometer data to incident photon and, by extension, electron beam information. In this study, we compare the performance QR decomposition, a matrix deconstruction technique and neural network with and without maximum likelihood estimation (MLE). Although QR decomposition proved to be the most effective theoretically, combining machine learning and MLE proved to be superior in the presence of noise, indicating its promise for analysis pipelines involving high-energy photons.

physics.acc-ph↗
arXiv2024

Analysis of the blowout plasma wakefields produced by drive beams with elliptical symmetry

In the underdense (blowout) regime of plasma wakefield acceleration (PWFA), the particle beam is denser than the plasma. Under these conditions, the plasma electrons are nearly completely rarefacted from the beam channel, resulting in a nominally uniform ion column. Extensive investigations of this interaction assuming axisymmetry have been undertaken. However, the plasma blowout produced by a transversely asymmetric driver possesses quite different characteristics. They create an asymmetric plasma rarefaction region (bubble) which leads to asymmetric focusing in the two transverse planes. This is also accompanied by an undesired non-uniform accelerating gradient. The asymmetric blowout cross-section is found through simulation to be elliptical, and treating it as such permits a simple extension of the symmetric theory. In particular, focusing fields linear in both transverse directions exist in the bubble. The form of the wake potential and the concomitant matching conditions in this elliptical cavity are discussed in this paper. We also discuss bubble boundary estimation in the long driver limit and applications of the asymmetric features of the wakefield.

physics.acc-ph↗
arXiv2023

Modeling betatron radiation using particle-in-cell codes for plasma wakefield accelerator diagnostics

The characterization of plasma wakefield acceleration experiments using emitted photons from betatron radiation requires numerical models in support of instrumentation of single-shot, double-differential angular-energy spectra. Precision characterization for relevant experiments necessitates covering a wide energy range extending from tens of keV through 10~GeV, with an angular resolution on the order of $100 \;\mu\text{rad}$. In this paper, we present a numerical model for betatron radiation from plasma accelerated beams, that are based on integration of Lienard Wiechert (LW) potentials for computed particle trajectories. The particle trajectories are generated in three different ways: first, by particle tracking through idealized fields in the blowout regime of PWFA; second, by obtaining trajectories from the Quasi-static Particle-in-Cell (PIC) code QuickPIC; and third, by obtaining trajectories from the full PIC code OSIRIS. We performed various benchmarks with analytical expressions and the PIC code EPOCH, which uses a Monte-Carlo QED radiation model. Finally, we present simulations of the expected betatron radiation for parameters from the Facility for Advanced Accelerator Experimental Tests II (FACET-II) PWFA and plasma photocathode experiments.

physics.acc-ph↗
arXiv2022

Machine learning-based analysis of experimental electron beams and gamma energy distributions

The photon flux resulting from high-energy electron beam interactions with high field systems, such as in the upcoming FACET-II experiments at SLAC National Accelerator Laboratory, may give deep insight into the electron beam's underlying dynamics at the interaction point. Extraction of this information is an intricate process, however. To demonstrate how to approach this challenge with modern methods, this paper utilizes data from simulated plasma wakefield acceleration-derived betatron radiation experiments and high-field laser-electron-based radiation production to determine reliable methods of reconstructing key beam and interaction properties. For these measurements, recovering the emitted 200 keV to 10 GeV photon energy spectra from two advanced spectrometers now being commissioned requires testing multiple methods to finalize a pipeline from their responses to incident electron beam information. In each case, we compare the performance of: neural networks, which detect patterns between data sets through repeated training; maximum likelihood estimation (MLE), a statistical technique used to determine unknown parameters from the distribution of observed data; and a hybrid approach combining the two. Further, in the case of photons with energies above 30 MeV, we also examine the efficacy of QR decomposition, a matrix decomposition method. The betatron radiation and the high-energy photon cases demonstrate the effectiveness of a hybrid ML-MLE approach, while the high-field electrodynamics interaction and the low-energy photon cases showcased the machine learning (ML) model's efficiency in the presence of noise. As such, while there is utility in all the methods, the ML-MLE hybrid approach proves to be the most generalizable.

physics.acc-ph↗
arXiv2022

A Call to Arms Control: Synergies between Nonproliferation Applications of Neutrino Detectors and Large-Scale Fundamental Neutrino Physics Experiments

The High Energy Physics community can benefit from a natural synergy in research activities into next-generation large-scale water and scintillator neutrino detectors, now being studied for remote reactor monitoring, discovery and exclusion applications in cooperative nonproliferation contexts. Since approximately 2010, US nonproliferation researchers, supported by the National Nuclear Security Administration (NNSA), have been studying a range of possible applications of relatively large (100 ton) to very large (hundreds of kiloton) water and scintillator neutrino detectors. In parallel, the fundamental physics community has been developing detectors at similar scales and with similar design features for a range of high-priority physics topics, primarily in fundamental neutrino physics. These topics include neutrino oscillation studies at beams and reactors, solar, and geological neutrino measurements, supernova studies, and others. Examples of ongoing synergistic work at U.S. national laboratories and universities include prototype gadolinium-doped water and water-based and opaque scintillator test-beds and demonstrators, extensive testing and industry partnerships related to large area fast position-sensitive photomultiplier tubes, and the development of concepts for a possible underground kiloton-scale water-based detector for reactor monitoring and technology demonstrations. Some opportunities for engagement between the two communities include bi-annual Applied Antineutrino Physics conferences, collaboration with U.S. National Laboratories engaging in this research, and occasional NNSA funding opportunities supporting a blend of nonproliferation and basic science R&D, directed at the U.S. academic community.

physics.ins-det↗
arXiv2021

Modeling Betatron Radiation Diagnostics for E-310 -- Trojan Horse

The E-310 experiment at the Facility for Advanced Accelerator Experimental Tests II (FACET-II) at SLAC National Accelerator Laboratory aims to demonstrate the creation of high brightness beams from a plasma photocathode. Betatron radiation will be measured by a Compton spectrometer, currently under development at UCLA, to provide single-shot, nondestructive beam diagnostics. We give a brief overview of this spectrometer as well as double differential spectrum reconstruction from the spectrometer image and beam parameter reconstruction from this double differential spectrum. We discuss three models for betatron radiation: an idealized particle tracking code which computes radiation from Liénard-Wiechert potentials, a quasi-static particle-in-cell (PIC) code which computes radiation from Liénard-Wiechert potentials, and a full PIC code which computes radiation using a Monte Carlo QED method. Spectra computed by the three models for a simple case are compared.

physics.acc-ph↗
arXiv2021

Theia: An advanced optical neutrino detector

New developments in liquid scintillators, high-efficiency, fast photon detectors, and chromatic photon sorting have opened up the possibility for building a large-scale detector that can discriminate between Cherenkov and scintillation signals. Such a detector could exploit these two distinct signals to observe particle direction and species using Cherenkov light while also having the excellent energy resolution and low threshold of a scintillator detector. Situated in a deep underground laboratory, and utilizing new techniques in computing and reconstruction techniques, such a detector could achieve unprecedented levels of background rejection, thus enabling a rich physics program that would span topics in nuclear, high-energy, and astrophysics, and across a dynamic range from hundreds of keV to many GeV. The scientific program would include observations of low- and high-energy solar neutrinos, determination of neutrino mass ordering and measurement of the neutrino CP violating phase, observations of diffuse supernova neutrinos and neutrinos from a supernova burst, sensitive searches for nucleon decay and, ultimately, a search for NeutrinoLess Double Beta Decay (NLDBD) with sensitivity reaching the normal ordering regime of neutrino mass phase space. This paper describes Theia, a detector design that incorporates these new technologies in a practical and affordable way to accomplish the science goals described above. We consider two scenarios, one in which Theia would reside in a cavern the size and shape of the caverns intended to be excavated for the Deep Underground Neutrino Experiment (DUNE) which we call Theia 25, and a larger 100 ktonne version (Theia 100) that could achieve an even broader and more sensitive scientific program.

physics.ins-det↗
arXiv2020

An Ultra-Compact X-Ray Free-Electron Laser

In the field of beam physics, two frontier topics have taken center stage due to their potential to enable new approaches to discovery in a wide swath of science. These areas are: advanced, high gradient acceleration techniques, and x-ray free electron lasers (XFELs). Further, there is intense interest in the marriage of these two fields, with the goal of producing a very compact XFEL. In this context, recent advances in high gradient radio-frequency cryogenic copper structure research have opened the door to the use of surface electric fields between 250 and 500 MV/m. Such an approach is foreseen to enable a new generation of photoinjectors with six-dimensional beam brightness beyond the current state-of-the-art by well over an order of magnitude. This advance is an essential ingredient enabling an ultra-compact XFEL (UC-XFEL). In addition, one may accelerate these bright beams to GeV scale in less than 10 meters. Such an injector, when combined with inverse free electron laser-based bunching techniques can produce multi-kA beams with unprecedented beam quality, quantified by ~50 nm-rad normalized emittances. These beams, when injected into innovative, short-period (1-10 mm) undulators uniquely enable UC-XFELs having footprints consistent with university-scale laboratories. We describe the architecture and predicted performance of this novel light source, which promises photon production per pulse of a few percent of existing XFEL sources. We review implementation issues including collective beam effects, compact x-ray optics systems, and other relevant technical challenges. To illustrate the potential of such a light source to fundamentally change the current paradigm of XFELs with their limited access, we examine possible applications in biology, chemistry, materials, atomic physics, industry, and medicine which may profit from this new model of performing XFEL science.

physics.acc-ph↗
arXiv2018

Light Yield of Perovskite Nanocrystal-Doped Liquid Scintillator

Liquid scintillators doped with metals are needed for a variety of measurements in nuclear and particle physics. Nanoparticles provide a mechanism to dope the scintillator and their unique optical properties could be used to enhance detection capabilities. We present here the first study of lead-based perovskite nanoparticles for this application. Perovskites are an attractive choice due to the versatility of their crystal structure and their ease of synthesis.

physics.ins-det↗
arXiv2017

Experimental characterization of electron beam driven wakefield modes in a dielectric woodpile Cartesian symmetric structure

The use of photonic structures in the terahertz (THz) spectral region may enable the essential characteristics of confinement, modal control, and electric field shielding for very high gradient accelerators based on wakefields in dielectrics. We report here an experimental investigation of THz wakefield modes in a 3D photonic woodpile structure. Selective control in exciting or suppressing of wakefield modes with non-zero transverse wave vector is demonstrated by using drive beams of varying transverse ellipticity. Additionally, we show that the wakefield spectrum is insensitive to the offset position of the strongly elliptical beam. These results are consistent with analytic theory and 3D simulations, and illustrate a key advantage of wakefield systems with Cartesian symmetry, the suppression of transverse wakes by elliptical beams.

physics.acc-ph↗
arXiv2007

Comment on "Taleyarkhan et al. Reply:"

In their Reply to my previous Comment, Taleyarkhan and coauthors measure their detectors' responses to a Cf-252 source, concluding that the resulting spectra differ substantially from the cavitation-fusion spectra published earlier in their Letter. On the contrary, I conclude that the two data sets are qualitatively consistent.

physics.gen-ph↗
arXiv2006

Comment on "Nuclear Emissions During Self-Nucleated Acoustic Cavitation"

In a recent Letter to PRL, Taleyarkhan and coauthors claim to observe DD fusion produced by acoustic cavitation. Among other evidence, they provide a proton recoil spectrum that they interpret as arising from 2.45 MeV DD fusion neutrons. My analysis concludes the spectrum is inconsistent with 2.45 MeV neutrons, cosmic background, or a PuBe source, but it is consistent with a Cf-252 source.

physics.gen-ph↗
arXiv2006

Supplementary Methods for "Comment on 'Nuclear Emissions During Self-Nucleated Acoustic Cavitation'"

Neutron simulation methods and statistical fitting methods for "Comment on 'Nuclear Emissions During Self-Nucleated Acoustic Cavitation'" are presented. The fit that underlies the Comment's background-subtracted "Cf-252" curve is shown. Also included are numerically sampled distributions of the goodness-of-fit variable for the four candidate neutron sources and a sketch of the assumed geometry.

physics.gen-ph↗