Latest in physics.acc-ph

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Collimated gamma-ray beams from structured laser-irradiated targets -- how to increase the efficiency without increasing the laser intensityAug 18 2019Using three-dimensional kinetic simulations, we examine the emission of collimated gamma-ray beams from structured laser-irradiated targets with a pre-filled cylindrical channel. The channel guides the incident laser pulse, enabling generation of a slowly ... More
Further searches of the Higgs scalar sector at the ESSAug 14 2019Recent decades have witnessed remarkable confirmations of the Standard Model (SM) describing the Electro-Weak and Strong Interactions. The Higgs boson was observed at CERN-LHC at 5 TeV and 13 TeV. The HL-LHC, a major luminosity upgrade has been recently ... More
Quantum Emergence of Linear Particle Accelerator and Anomalous Photon-induced Near-field Electron Microscopy in a Strong Coupling RegimeAug 14 2019Photon-induced near-field electron microscopy (PINEM) is a currently developing spectral approach that characterizes quantum electron-light interactions in electron energy gain/loss spectrum, with symmetrically discretized gains or losses of light quanta ... More
Acceleration of relativistic beams using laser-generated terahertz pulsesAug 12 2019Dielectric structures driven by laser-generated terahertz (THz) pulses may hold the key to overcoming the technological limitations of conventional particle accelerators and with recent experimental demonstrations of acceleration, compression and streaking ... More
Estimation of Spectral Clustering Hyper ParametersAug 10 2019Robust automation of analysis procedures capable of handling diverse data sets is critical for high data throughput experiments at the Linac Coherent Light Source (LCLS). One challenge encountered in this process is determining the number of clusters ... More
Target Considerations for a Very Cold Neutron SourceAug 09 2019A proposed Very Cold Neutron Source (VCNS) would operate with 4 ms long pulses at 5 Hz and 1 GeV. The energy per pulse would be 300 kJ, much higher than the Spallation Neutron Source (33 kJ/pulse) or the present IPNS (0.3 kJ/pulse), and the peak power ... More
Hamiltonian preserving nonlinear opticsAug 09 2019An accelerator lattice could be considered as a map that transforms the phase space coordinates of a beam. Formally, such a transformation leads to a time-dependent effective Hamiltonian of the system, and this does not guarantee optimal dynamic properties. ... More
Fast longitudinal beam dynamics optimization in x-ray FEL linear acceleratorsAug 09 2019A high peak current, flat longitudinal phase space electron beam is desirable for efficient x-ray free electron laser (FEL) radiation in next generation light sources. To attain such a beam requires the extensive design of the linear accelerator (linac) ... More
Transverse Microwave Convective Instability at Transition CrossingAug 08 2019An analytical model of transverse convective instability of a bunch at transition crossing is presented for the microwave case, when the wake is sufficiently short compared with the bunch length. The space charge is assumed to be strong, as it typically ... More
Beam-beam effects on the luminosity measurement at LEP and the number of light neutrino speciesAug 05 2019Aug 06 2019In $e^+e^-$ collisions, electromagnetic effects caused by large charge density bunches modify the effective acceptance of the luminometer system of the experiments. These effects consequently bias the luminosity measurement from the rate of low-angle ... More
Beam-beam effects on the luminosity measurement at FCC-eeAug 05 2019The first part of the physics programme of the integrated FCC (Future Circular Colliders) proposal includes measurements of Standard Model processes in $e^+e^-$ collisions (FCC-ee) with an unprecedented precision. In particular, the potential precision ... More
Beam-beam effects on the luminosity measurement at FCC-eeAug 05 2019Aug 06 2019The first part of the physics programme of the integrated FCC (Future Circular Colliders) proposal includes measurements of Standard Model processes in $e^+e^-$ collisions (FCC-ee) with an unprecedented precision. In particular, the potential precision ... More
Coupling Effects in Multi-Stage Laser Wake-field Acceleration of ElectronsAug 05 2019Staging laser wake-field acceleration is considered as a necessary technique for developing full-optical jitter-free electron accelerators. Splitting of the acceleration length into several technical parts with their lengths smaller than the dephasing ... More
Spin dynamics investigations for the EDM experiment at COSYAug 01 2019Precision experiments, such as the search for a deuteron electric dipole moments using a storage rings like COSY, demand for an understanding of the spin dynamics with unprecedented accuracy. In such an enterprise, numerical predictions play a crucial ... More
Complex Representation of Potentials and Fields for the Nonlinear Magnetic Insert of the Integrable Optics Test AcceleratorJul 31 2019An alternative representation for the vector potential of the nonlinear magnetic insert for the Integrable Optics Test Accelerator (IOTA), first described in Sec. V.A. of the paper of Danilov and Nagaitsev, is determined from first principles using standard ... More
A Numerical Approach to Designing a Versatile Pepper-pot Mask for Emittance MeasurementJul 31 2019Aug 01 2019The pepper-pot method is a popular emittance measurement technique for high intensity beams at low energy such as those generated by photo-injectors. In this paper, the beam dynamics in the space charge dominated regime and analytical design criteria ... More
A Numerical Approach to Designing a Versatile Pepper-pot Mask for Emittance MeasurementJul 31 2019The pepper-pot method is a popular emittance measurement technique for high intensity beams at low energy such as those generated by photo-injectors. In this paper, the beam dynamics in the space charge dominated regime and analytical design criteria ... More
Multiple Energy Storage RingsJul 31 2019Energy recovery linacs have been studied and developed over a number of decades. In the standard arrangement there is a separate particle source and particle beam dump. In this paper, a new arrangement is explored where the energy recovery linac is used ... More
Probing Ultrafast Magnetic-Field Generation by Current Filamentation Instability in Femtosecond Relativistic Laser-Matter InteractionsJul 28 2019We present experimental measurements of the femtosecond time-scale generation of strong magnetic-field fluctuations during the interaction of ultrashort, moderately relativistic laser pulses with solid targets. These fields were probed using low-emittance, ... More
Beam Optics Primer using Octave or MATLABJul 25 2019This primer provides a basic introduction to beam optics concepts that are commonly used to describe charged particle accelerators.
Analysis of the non-linear beam dynamics at top energy for the CERN Large Hadron Collider by means of a diffusion modelJul 25 2019In this paper the experimental results of the recent dynamic aperture at top energy for the CERN Large Hadron Collider are analysed by means of a diffusion model whose novelty consists of deriving the functional form of the diffusion coefficient from ... More
Fast high-power thyristors triggered in impact-ionization wave modeJul 24 2019GTO-like thyristors 5STH-2045H0002 (4.5 kV, 18 kA/us) developed by ABB semiconductors are currently used at CERN in LHC Beam Dumping System (LBDS): high-power switches with high dI/dt capability and low turn-on delay time are required. Implementation ... More
Simulation of a radiobiology facility for the Centre for the Clinical Application of ParticlesJul 23 2019The Centre for the Clinical Application of Particles' Laser-hybrid Accelerator for Radiobiological Applications (LhARA) facility is being studied and requires simulation of novel accelerator components (such as the Gabor lens capture system), detector ... More
Material development towards a solid 100 kW electron-gamma converter for TRIUMF-ARIELJul 22 2019A series of irradiation tests have been performed at TRIUMF to investigate different material pairings to act as high-power electron-to-gamma converter for the ARIEL Electron Target East (AETE). The bulk of the converter body will be made out of an aluminum ... More
Systematic benchmarking of planar nitrogen-incorporated ultrananocrystalline diamond field emission electron source: rf conditioning and beam spatio-temporal characteristicsJul 19 2019Planar nitrogen-incorporated ultrananocrystalline diamond, (N)UNCD, has emerged as a unique field emission source attractive for accelerator applications because of its capability to generate high charge beam and handle moderate vacuum conditions. Most ... More
Systematic benchmarking of planar nitrogen-incorporated ultrananocrystalline diamond field emission electron source: rf conditioning and beam spatio-temporal characteristicsJul 19 2019Jul 28 2019Planar nitrogen-incorporated ultrananocrystalline diamond, (N)UNCD, has emerged as a unique field emission source attractive for accelerator applications because of its capability to generate high charge beam and handle moderate vacuum conditions. Most ... More
First demonstration of ionization cooling by the Muon Ionization Cooling ExperimentJul 19 2019High-brightness muon beams of energy comparable to those produced by state-of-the-art electron, proton and ion accelerators have yet to be realised. Such beams have the potential to carry the search for new phenomena in lepton-antilepton collisions to ... More
Interferometric optical signature of electron microbunching in laser-driven plasma acceleratorsJul 11 2019We report observations of coherent optical transition radiation interferometry (COTRI) patterns generated by microbunched ~200-MeV electrons as they emerge from a laser-plasma accelerator. The divergence of the microbunched portion of electrons, deduced ... More
Multi-beam-energy operation for the continuous-wave x-ray free electron laserJul 09 2019The parallel operation of multiple undulator lines with a wide spectral range is an important way to increase the efficiency of x-ray free electron laser (XFEL) facilities, especially for machines with high-repetition-rate. In this paper, a delay system ... More
Multi-beam-energy operation for the continuous-wave x-ray free electron laserJul 09 2019Jul 22 2019The parallel operation of multiple undulator lines with a wide spectral range is an important way to increase the efficiency of x-ray free electron laser (XFEL) facilities, especially for machines with high-repetition-rate. In this paper, a delay system ... More
Coherence properties of the high-energy fourth-generation X-ray synchrotron sourcesJul 08 2019We performed an analysis of coherence properties of the 4-th generation high-energy storage rings with emittance values of 10 pmrad. It is presently expected that a storage ring with these low emittance values will reach diffraction limit at hard X-rays. ... More
Evaluation of the superconducting characteristics of multi-layer thin-film structures of NbN and SiO$_2$ on pure Nb substrateJul 08 2019In recent years, it has been pointed out that the maximum accelerating gradient of a superconducting RF cavity can be increased by coating the inner surface of the cavity with a multilayer thin-film structure consisting of alternating insulating and superconducting ... More
Lower critical field measurement of NbN multilayer thin film superconductor at KEKJul 08 2019The multilayer thin film structure of the superconductor has been proposed by A. Gurevich to enhance the maximum gradient of SRF cavities. The lower critical field Hc1 at which the vortex starts penetrating the superconducting material will be improved ... More
Probability of radiation of twisted photons in an inhomogeneous isotropic dispersive mediumJul 04 2019The general formula for probability to record a twisted photon produced by a charged particle moving in an inhomogeneous isotropic dispersive medium is derived. The explicit formulas for probability to record a twisted photon are obtained for the radiation ... More
Probability of radiation of twisted photons in an inhomogeneous isotropic dispersive mediumJul 04 2019Jul 11 2019The general formula for probability to record a twisted photon produced by a charged particle moving in an inhomogeneous isotropic dispersive medium is derived. The explicit formulas for probability to record a twisted photon are obtained for the radiation ... More
A facility for direct measurements for nuclear astrophysics at IFIN-HH -- a 3 MV tandem accelerator and an ultra-low background laboratoryJul 04 2019We present a facility for direct measurements at low and very low energies typical for nuclear astrophysics (NA). The facility consists of a small and robust tandem accelerator where irradiations are made, and an ultra-low background laboratory located ... More
Accurate single-shot measurement technique for the spectral distribution of GeV electron beams from a laser wakefield acceleratorJul 04 2019We present a technique, based on a dipole magnet spectrometer containing multiple scintillation screens, to accurately characterize the spectral distribution of a GeV electron beam generated by laser wakefield acceleration (LWFA). An optimization algorithm ... More
Compact buncher cavity for muons accelerated by a radio-frequency quadrupoleJul 04 2019A buncher cavity has been developed for the muons accelerated by a radio-frequency quadrupole linac (RFQ). The buncher cavity is designed for $\beta=v/c=0.04$ at an operational frequency of 324 MHz. It employs a double-gap structure operated in the TEM ... More
Tailoring of an Electron-Bunch Current Distribution via Space-to-Time Mapping of a Transversely-Shaped Photoemission-Laser PulseJul 03 2019Temporally-shaped electron bunches at ultrafast time scales are foreseen to support an array of applications including the development of small-footprint accelerator-based coherent light sources or as probes for, e.g., ultrafast electron-diffraction. ... More
Future High Energy Frontier CollidersJul 02 2019Colliders have been at the forefront of scientic discoveries in high-energy particle physics since the inception of the colliding beams method in the middle of the 20th century. The field of accelerators is very dynamic and many innovative concepts are ... More
Phase modulation in storage-ring RF systemsJul 02 2019This paper presents a conceptual approach to phase modulation of the cavity field in storage ring RF systems. An implementation of the concept on Dimtel low-level RF controllers is also presented. The method is illustrated with the test results from a ... More
Obliquely Incident Laser and Electron Beam Interaction in an UndulatorJul 02 2019The angular drift of a laser beam is of particular concern in applications such as seeded free-electron lasers. A systematical study of the obliquely incident laser and electron beam interaction in an undulator is presented in this paper. Theoretical ... More
Analytic models of magnetically enclosed spherical and solenoidal coilsJul 02 2019We provide analytic solutions of the net magnetic field generated by spherical and solenoidal coils enclosed in highly-permeable, coaxial magnetic shields. We consider both spherical and cylindrical shields in the case of the spherical coil and only cylindrical ... More
A compact electron injector for the EIC based on plasma wakefields driven by the RHIC-EIC proton beamJul 02 2019Initial simulations investigating using the RHIC-EIC proton beam as the drive beam in a plasma wakefield acceleration experiment are presented. The proton beam enters the plasma and undergoes self-modulation, forming a series of microbunches. These microbunches ... More
Development and high-power testing of an X-band dielectric-loaded power extractorJul 01 2019Dielectric loaded structures are promising candidates for use in the structure wakefield acceleration (SWFA) technique, for both the collinear wakefield and the two-beam acceleration (CWA and TBA respectively) approaches, due to their low fabrication ... More
Electron bunch generation from a plasma photocathodeJul 01 2019Plasma waves generated in the wake of intense, relativistic laser or particle beams can accelerate electron bunches to giga-electronvolt (GeV) energies in centimetre-scale distances. This allows the realization of compact accelerators having emerging ... More
Mapping electromagnetic fields structure in plasma using a spin polarized electron beamJul 01 2019We propose a scheme to mapping electromagnetic fields structure in plasma by using a spin polarized relativistic electron beam. Especially by using Particle-in-Cell (PIC) and electron spin tracing simulations, we have successfully reconstructed a plasma ... More
Ultra-Low Surface Resistance via Vacuum Heat Treatment of Superconducting Radiofrequency CavitiesJun 29 2019We report on an effort to improve the performance of superconducting radiofrequency cavities by the use of heat treatment in a temperature range sufficient to dissociate the natural surface oxide. We find that the residual resistance is significantly ... More
Non-stochastic electron acceleration in multipicosecond laser-solid interaction at relativistic intensityJun 27 2019We study energetic electron generation in the characteristic long underdense ion shelf and opaque plasma wall preplasma profile created by multipicosecond, relativistic intensity laser pulses incident on solid density targets. In 1D particle-in-cell simulations, ... More
On the quest of low temperature nitrogen infusion relevant for superconducting Nb based radio-frequency cavitiesJun 27 2019A detailed study of the near-surface structure and composition of Nb, the material of choice for Superconducting Radio Frequency accelerator (SRF) cavities, is of great importance in order to understand the effects of different treatments applied during ... More
Interferometry for full temporal reconstruction of laser-plasma accelerator-based seeded free electron lasersJun 26 2019The spectacular development of Laser-Plasma Accelerators (LPA) appears very promising for a free electron laser application. The handling of the inherent properties of those LPA beams already allowed controlled production of LPA-based spontaneous undulator ... More
Interferometry for full temporal reconstruction of laser-plasma accelerator-based seeded free electron lasersJun 26 2019Jun 28 2019The spectacular development of Laser-Plasma Accelerators (LPA) appears very promising for a free electron laser application. The handling of the inherent properties of those LPA beams already allowed controlled production of LPA-based spontaneous undulator ... More
Tunable Isolated Attosecond X-ray Pulses with Gigawatt Peak Power from a Free-Electron LaserJun 25 2019The quantum mechanical motion of electrons in molecules and solids occurs on the sub-femtosecond timescale. Consequently, the study of ultrafast electronic phenomena requires the generation of laser pulses shorter than 1 fs and of sufficient intensity ... More
High Resolution and High Precision Beam Profile Monitor for Particle AcceleratorJun 25 2019A compact beam profile monitor was developed using a plastic scintillator attached with a contact image sensor and tested by a 230 MeV proton beam. The results indicate that the beam distribution could be obtained in real-time and the precision of the ... More
Weak focusing low emittance storage ring with large 6d dynamic aperture based on canted cosine theta magnet technologyJun 24 2019We developed a low emittance electron storage ring with large 6D dynamic aperture. Contrary to the traditional approach using strong focusing magnetic cells with optimized (and large) horizontal phase advance, which yields huge natural chromaticity, we ... More
Output coupling from x-ray free-electron laser cavities with intracavity beam splittersJun 22 2019Permeable mirrors are typically used for coupling photons out of laser cavities. A similar approach was proposed for output coupling photons from the cavities of x-ray free-electron laser (XFEL) oscillators. One of the Bragg-reflecting crystal mirrors ... More
Uncertainty Modeling and Analysis of the European XFEL Cavities Manufacturing ProcessJun 21 2019This paper reports on comprehensive efforts on uncertainty quantification and global sensitivity analysis for accelerator cavity design. As a case study object the TESLA shaped superconducting cavities, as produced for the European X-ray Free Electron ... More
Layouts for fixed-target experiments and dipole moment measurements of short-living baryons using bent crystals at the LHCJun 20 2019Several studies are on-going at CERN in the framework of the Physics Beyond Collider study group, with main aim of broadening the physics research spectrum using the available accelerator complex and infrastructure. The possibility to design a layout ... More
Lower Critical Field Measurement System based on Third-Harmonic Method for Superconducting RF MaterialsJun 20 2019We develop a lower critical field (Hc1) measurement system using the third-harmonic response of an applied AC magnetic field from a solenoid coil positioned above a superconducting sample. Parameter Hc1 is measured via detection of the third-harmonic ... More
Transverse forces in planar symmetric dielectric laser-driven acceleratorsJun 19 2019The use of dielectric microstructures driven by solid state lasers to accelerate charged particles or to transversely deflect them is a growing area of scientific interest with an international collaboration of researchers working to develop this concept. ... More
Thermal emittance mapping of a cesium telluride photocathode using microlens-arrays based laser pattern beamJun 19 2019The thermal emittance map of the cesium telluride photocathode is measured using a laser pattern beam produced by microlens arrays. A pair of MLAs are employed to produce a periodic transverse pattern beam, consisting of a two-dimensional array of laser ... More
Compact Rare-Earth Superconducting CyclotronJun 18 2019The use of superconductivity is well-known as a method to increase the average field of a cyclotron and thereby to allow a substantial reduction of its size and mass. We present a compact high-field design for the first superconducting cyclotron with ... More
First Attempts in Automated Defect Recognition in Superconducting Radio-Frequency CavitiesJun 18 2019The inner surface of superconducting cavities plays a crucial role to achieve highest accelerating fields. The industrial fabrication of cavities for the European X-Ray Free Electron Laser (EXFEL) and the International Linear Collider (ILC) HiGrade Research ... More
Future Accelerator-Based Neutrino BeamsJun 18 2019High energy and high beam power accelerators are extensively used for the neutrino physics research. At present, the leading operational facilities are the Fermilab Main Injector complex that delivers over 0.75 MW of 120 GeV protons on the neutrino target, ... More
Femtosecond relativistic electron beam with reduced timing jitter from THz-driven beam compressionJun 17 2019We propose and demonstrate a novel method to reduce the pulse width and timing jitter of a relativistic electron beam through THz-driven beam compression. In this method the longitudinal phase space of a relativistic electron beam is manipulated by a ... More
Plasma Waves in a Different Frame: a Tutorial for Plasma-based Electron AcceleratorsJun 14 2019We present an analysis of a nonlinear, relativistic longitudinal wave with sub-luminal phase velocity $v_p$ in a cold plasma. By a Lorentz transformation to a frame co-moving at velocity $v_p$ we reduce the problem to a simple second-order ordinary differential ... More
Plasma Waves in a Different Frame: a Tutorial for Plasma-based Electron AcceleratorsJun 14 2019Jul 02 2019Nonlinear, relativistic longitudinal waves with sub-luminal phase velocity $v_p$ are the basis of plasma-based electron accelerators. For such application, key properties of the wave are the maximum or ``wave breaking'' amplitude and the corresponding ... More
Terahertz Acceleration Technology Towards Compact Light SourcesJun 13 2019The concepts in this thesis comprise three groups focusing on: (1) fast electron sources, (2) THz injectors, and (3) THz linacs. First, the feasibility of ultrafast, high-yield electron emitters based on nanostructured cathodes is demonstrated. Benefitting ... More
Measuring the Gain of a Micro-Channel Plate/Phosphor Assembly Using a Convolutional Neural NetworkJun 13 2019This paper presents a technique to measure the gain of a single-plate micro-channel plate (MCP)/phosphor assembly by using a convolutional neural network to analyse images of the phosphor screen, recorded by a charge coupled device. The neural network ... More
Multiple-colliding laser pulses as a basis for studying high-field high-energy physicsJun 12 2019Apart from maximizing the strength of optical electromagnetic fields achievable at high-intensity laser facilities, the collision of several phase-matched laser pulses has been theoretically identified as a trigger of and way to study various phenomena. ... More
Nanosecond pulsed proton beam: upgrade of the accelerator-based neutron facility HiSPANOS at CNA (Spain)Jun 12 2019The 3 MV Tandem Pelletron accelerator at the Spanish Accelerator Laboratory (CNA) has been recently upgraded to produce pulsed ion beams for neutron Time-Of-Flight (TOF) measurements. The upgrade has consisted of two actions: a pulsing system installed ... More
Ray interpretation of the transition radiation process in a waveguideJun 11 2019The paper demonstrates the geometric optic properties of the transition radiation (TR) of an ultrarelativistic point-like charged particle crossing the transverse wall of a circular semi-infinite waveguide with ideally conducting walls. It is shown that ... More
Femtosecond compression dynamics and timing jitter suppression in a terahertz-driven electron bunch compressorJun 07 2019We present the first demonstration of THz-driven bunch compression and timing stabilization of a few-fC relativistic electron beam with kinetic energy of 2.5 MeV using quasi-single-cycle strong field THz radiation in a shorted parallel-plate structure. ... More
Flux expulsion in niobium superconducting radio-frequency cavities of different purity and essential contributions to the flux sensitivityJun 06 2019Magnetic flux trapped during the cooldown of superconducting radio-frequency cavities through the transition temperature due to incomplete Meissner state is known to be a significant source of radio-frequency losses. The sensitivity of flux trapping depends ... More
FCC-ee: Your Questions AnsweredJun 06 2019This document answers in simple terms many FAQs about FCC-ee, including comparisons with other colliders. It complements the FCC-ee CDR and the FCC Physics CDR by addressing many questions from non-experts and clarifying issues raised during the European ... More
Nanopatterned electron beams for temporal coherence and deterministic phase control of x-ray free-electron lasersJun 04 2019We demonstrate the ability to create electron beams with high-contrast, nanometer-scale density modulations as a first step toward developing full control of the phase fronts of an x-ray free-electron laser. The nanopatterned electron beams are produced ... More
Comparison Between, and Validation Against an Experiment of, a Slowly-Varying Envelope Approximation Code and a Particle-in-Cell Simulation Code for Free-Electron LasersJun 04 2019Free-electron lasers (FELs) operate at wavelengths down to hard x-rays, and are either seeded or start from noise. There is increasing interest in x-ray FELs that rely on Self-Amplified Spontaneous Emission (SASE), and this involves increasing simulation ... More
Comparison Between, and Validation Against an Experiment of, a Slowly-Varying Envelope Approximation Code and a Particle-in-Cell Simulation Code for Free-Electron LasersJun 04 2019Jun 17 2019Free-electron lasers (FELs) operate at wavelengths down to hard x-rays, and are either seeded or start from noise. There is increasing interest in x-ray FELs that rely on Self-Amplified Spontaneous Emission (SASE), and this involves increasing simulation ... More
Constrained multi-objective shape optimization of superconducting RF cavities considering robustness against geometric perturbationsMay 31 2019High current storage rings, such as the Z-pole operating mode of the FCC-ee, require accelerating cavities that are optimized with respect to both the fundamental mode and the higher order modes. Furthermore, the cavity shape needs to be robust against ... More
RMATE: A device to test radiation-induced effects under controlled magnetic field and temperatureMay 28 2019This study shows the development and performance assessment of a novel set-up that enables the research of structural materials for fusion reactors, by making possible simultaneous application of temperature (up to 450$^{\circ}$C) and magnetic field (close ... More
RF design of APEX2 two-cell continuous-wave normal conducting photoelectron gun cavity based on multi-objective genetic algorithmMay 25 2019High brightness, high repetition rate electron beams are key components for optimizing the performance of next generation scientific instruments, such as MHz-class X-ray Free Electron Laser (XFEL) and Ultra-fast Electron Diffraction/Microscopy (UED/UEM). ... More
RF design of APEX2 two-cell continuous-wave normal conducting photoelectron gun cavity based on multi-objective genetic algorithmMay 25 2019May 28 2019High brightness, high repetition rate electron beams are key components for optimizing the performance of next generation scientific instruments, such as MHz-class X-ray Free Electron Laser (XFEL) and Ultra-fast Electron Diffraction/Microscopy (UED/UEM). ... More
A high-gain Quantum free-electron laser: emergence & exponential gainMay 24 2019We derive an effective Dicke model in momentum space to describe collective effects in the quantum regime of a free-electron laser (FEL). The resulting exponential gain from a single passage of electrons allows the operation of a Quantum FEL in the high-gain ... More
Interaction between high intensity beam and structure resonancesMay 24 2019With the help of the linearized perturbation theory, the collective beam instability due to the space charge, modelled by the Vlasov-Poisson equation, is well studied in the former research theoretically in a general sense [Chao Li and R. A. Jameson PRAB, ... More
High repetition rate thermionic electron injector concept using higher harmonic cavitiesMay 22 2019May 23 2019Electron injectors are at the basis of Free-Electron Lasers and Inverse Compton Light Sources. Developing the next-generation injector will allow these accelerator-based light sources to meet the growing science demand for an increase in average brightness. ... More
High repetition rate thermionic electron injector concept using higher harmonic cavitiesMay 22 2019Electron injectors are at the basis of Free-Electron Lasers and Inverse Compton Light Sources. Developing the next-generation injector will allow these accelerator-based light sources to meet the growing science demand for an increase in average brightness. ... More
A fast-switching magnet serving a spallation-driven ultracold neutron sourceMay 21 2019A fast-switching, high-repetition-rate magnet and power supply have been developed for and operated at TRIUMF, to deliver a proton beam to the new ultracold neutron (UCN) facility. The facility possesses unique operational requirements: a time-averaged ... More
A fast-switching magnet serving a spallation-driven ultracold neutron sourceMay 21 2019Aug 11 2019A fast-switching, high-repetition-rate magnet and power supply have been developed for and operated at TRIUMF, to deliver a proton beam to the new ultracold neutron (UCN) facility. The facility possesses unique operational requirements: a time-averaged ... More
Bunch Length and Energy Measurements in the Bunch-Compressor of a Free-Electron-LaserMay 20 2019At SwissFEL, a fully non-invasive characterization of the beam energy distribution can be performed by means of a Synchrotron-Radiation-Monitor (SRM) imaging in the visible the transverse profile of the electron beam in a magnetic chicane. Under conditions ... More
Probability of radiation of twisted photons by cold relativistic particle bunchesMay 19 2019The probability to record a twisted photon produced by a cold relativistic particle bunch of charged particles is derived. The radiation of twisted photons by such particle bunches in stationary electromagnetic fields and in propagating electromagnetic ... More
A primary electron beam facility at CERNMay 18 2019This paper describes the concept of a primary electron beam facility at CERN, to be used for dark gauge force and light dark matter searches. The electron beam is produced in three stages: A Linac accelerates electrons from a photo-cathode up to 3.5 GeV. ... More
Theoretical and experimental electron diffraction intensity maps for single crystal silicon from an ultrafast sourceMay 17 2019Electron diffraction through a thin patterned silicon membrane can be used to create complex spatial modulations in electron distributions by varying the intensity of different reflections using parameters such as crystallographic orientation and wafer ... More
Theoretical and experimental electron diffraction intensity maps for single crystal silicon from an ultrafast sourceMay 17 2019May 29 2019Electron diffraction through a thin patterned silicon membrane can be used to create complex spatial modulations in electron distributions by varying the intensity of different reflections using parameters such as crystallographic orientation and wafer ... More
Theoretical and experimental electron diffraction intensity maps for single crystal silicon from an ultrafast sourceMay 17 2019May 21 2019Electron diffraction through a thin patterned silicon membrane can be used to create complex spatial modulations in electron distributions by varying the intensity of different reflections using parameters such as crystallographic orientation and wafer ... More
First fully kinetic three-dimensional simulation of the AWAKE baseline scenarioMay 17 2019The "Advanced Proton Driven Plasma Wakefield Acceleration Experiment" (AWAKE) aims to accelerate leptons via proton-beam-driven wakefield acceleration. It comprises extensive numerical studies as well as experiments at the CERN laboratory. The baseline ... More
Tunable X-ray source by Thomson scattering during laser-wakefield accelerationMay 16 2019We report results on all-optical Thomson scattering intercepting the acceleration process in a laser wakefield accelerator. We show that the pulse collision position can be detected using transverse shadowgraphy which also facilitates alignment. As the ... More
OPAL a Versatile Tool for Charged Particle Accelerator SimulationsMay 16 2019Many sophisticated computer models have been developed to understand the behaviour of particle accelerators. Even these complex models often do not describe the measured data. Interactions of the beam with external fields, other particles in the same ... More
An X-Ray Regenerative Amplifier Free-Electron Laser Using Diamond Pinhole MIrrorsMay 15 2019Free-electron lasers (FELs) have been built ranging in wavelength from long-wavelength oscillators using partial wave guiding through ultraviolet through hard x-ray FELs that are either seeded or start from noise (SASE). Operation in the x-ray spectrum ... More
Positron driven muon source for a muon colliderMay 14 2019The design of a future multi-TeV muon collider needs new ideas to overcome the technological challenges related to muon production, cooling, accumulation and acceleration. In this paper a layout of a positron driven muon source known as the Low EMittance ... More
Positron driven muon source for a muon colliderMay 14 2019May 19 2019The design of a future multi-TeV muon collider needs new ideas to overcome the technological challenges related to muon production, cooling, accumulation and acceleration. In this paper a layout of a positron driven muon source known as the Low EMittance ... More