Latest in physics.acc-ph

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Uncertainty Quantification for Geometry Deformations of Superconducting Cavities using Eigenvalue TrackingFeb 08 2018The electromagnetic field distribution as well as the resonating frequency of various modes in superconducting cavities are sensitive to small geometry deformations. The occurring variations are motivated by measurements of an available set of resonators ... More
Full PIC simulation of a first ACHIP experiment @ SINBADFeb 08 2018In laser illuminated dielectric accelerators (DLA) high acceleration gradients can be achieved due to high damage thresholds of the materials at optical frequencies. This is a necessity for developing more compact particle accelerator technologies. The ... More
Analytic plasma wakefield limits for active plasma lensesFeb 08 2018Active plasma lensing is a promising technology for compact focusing of particle beams that has seen a recent surge of interest. While these lenses can provide strong focusing gradients of order kT/m and focusing in both transverse planes, there are limitations ... More
Waferscale Electrostatic Quadrupole Array for Multiple Ion Beam ManipulationFeb 07 2018We report on the first through-wafer silicon-based Electrostatic Quadrupole Array (ESQA) to focus high energy ion beams. This device is a key enabler for a wafer based accelerator architecture that lends itself to orders-of-magnitude reduction in cost, ... More
Comment on 'Simulation of ultra-relativistic electrons and positrons channeling in crystals with MBN Explorer'Feb 07 2018The snapshot model of crystal atoms has been implemented in the Monte Carlo code ChaS (Channeling Simulator) and is being successfully used for simulation of ultrarelativistic particle channeling. The model has been criticized by Sushko et al. (J. Comp. ... More
Simulation of deflecting structures for dielectric laser driven acceleratorsFeb 06 2018In laser illuminated dielectric accelerators (DLA) high acceleration gradients can be achieved, due to high damage thresholds of the materials at optical frequencies. This is a necessity in developing more compact particle accelerator technologies. The ... More
First Measurements of Beam Backgrounds at SuperKEKBFeb 05 2018The high design luminosity of the SuperKEKB electron-positron collider is expected to result in challenging levels of beam-induced backgrounds in the interaction region. Properly simulating and mitigating these backgrounds is critical to the success of ... More
Characterization of self-injected electron beams from LWFA experiments at SPARC_LABFeb 03 2018The plasma-based acceleration is an encouraging technique to overcome the limits of the accelerating gradient in the conventional RF acceleration. A plasma accelerator is able to provide accelerating fields up to hundreds of $GeV/m$, paving the way to ... More
Modelling of pulse train generation for resonant laser wakefield acceleration using a delay maskFeb 02 2018A new method for the generation of a train of pulses from a single high-energy, ultra short pulse is presented, suited for Resonant Multi-Pulse Ionization injection. The method is based on different transverse portion of the pulse being delayed by a "mask" ... More
Electron-Terahertz Interaction in Dielectric-Lined Waveguide Structures for Electron ManipulationFeb 02 2018Terahertz-driven dielectric-lined waveguides (DLWs) have uses in electron manipulation; in particular deflection, acceleration, and focussing. A rectangular DLW has been optimised for deflection of 100 keV electrons using a THz pulse with a centre frequency ... More
The FLAME laser at SPARC_LABFeb 01 2018FLAME is a high power laser system installed at the SPARC_LAB Test Facility in Frascati (Italy). The ultra-intense laser pulses are employed to study the interaction with matter for many purposes: electron acceleration through LWFA, ion and proton generation ... More
Overview of Plasma Lens Experiments and Recent Results at SPARC_LABFeb 01 2018Beam injection and extraction from a plasma module is still one of the crucial aspects to solve in order to produce high quality electron beams with a plasma accelerator. Proper matching conditions require to focus the incoming high brightness beam down ... More
Demonstration of a compact linear acceleratorFeb 01 2018Recently, we presented a new approach for a compact radio-frequency (RF) accelerator structure and demonstrated the functionality of the individual components: acceleration units and focusing elements. In this paper, we combine these units to form a working ... More
Optimization of the beam crossing angle at the ILC for e+e- and gamma-gamma collisionsJan 31 2018At this time, the design of the International Linear Collider (ILC) is optimized for e+e- collisions; the photon collider (gamma-gamma and gamma-electron) is considered as an option. Unexpected discoveries, such as the diphoton excess F(750 GeV) seen ... More
Using short drive laser pulses to achieve net focusing forces in tailored dual grating dielectric structuresJan 31 2018Laser-driven grating type DLA (Dielectric Laser Accelerator) structures have been shown to produce accelerating gradients on the order of GeV/m. In simple $\beta$-matched grating structures due to the nature of the laser induced steady-state in-channel ... More
First application studies at the laser-driven LIGHT beamline: Improving proton beam homogeneity and imaging of a solid targetJan 30 2018In the last two decades, the generation of intense ion beams based on laser-driven sources has become an extensively investigated field. The LIGHT collaboration combines a laserdriven intense ion source with conventional accelerator technology based on ... More
Measurement Techniques for Low Emittance Tuning and Beam Dynamics at CESRJan 30 2018After operating as a High Energy Physics electron-positron collider, the Cornell Electron-positron Storage Ring (CESR) has been converted to become a dedicated synchrotron light source for the Cornell High Energy Synchrotron Source (CHESS). Over the course ... More
EUPRAXIA@SPARC_LAB: Beam Dynamics studies for the X-band LinacJan 30 2018In the framework of the Eupraxia Design Study an advanced accelerator facility EUPRAXIA@SPARC_LAB has been proposed to be realized at Frascati (Italy) Laboratories of INFN. Two advanced acceleration schemes will be applied, namely an ultimate high gradient ... More
STEAM: A Hierarchical Co-Simulation Framework for Superconducting Accelerator Magnet CircuitsJan 26 2018Simulating the transient effects occurring in superconducting accelerator magnet circuits requires including the mutual electro-thermo-dynamic interaction among the circuit elements, such as power converters, magnets, and protection systems. Nevertheless, ... More
EuPRAXIA@SPARC_LAB Design study towards a compact FEL facility at LNFJan 26 2018On the wake of the results obtained so far at the SPARC\_LAB test-facility at the Laboratori Nazionali di Frascati (Italy), we are currently investigating the possibility to design and build a new multi-disciplinary user-facility, equipped with a soft ... More
LUX -- A Laser-Plasma Driven Undulator BeamlineJan 23 2018The LUX beamline is a novel type of laser-plasma accelerator. Building on the joint expertise of the University of Hamburg and DESY the beamline was carefully designed to combine state-of-the-art expertise in laser-plasma acceleration with the latest ... More
About the coherent fraction of synchrotron emissionJan 23 2018Coherent fraction is a concept widely used in the synchrotron radiation community. Here I discuss the meaning of coherent fraction, an accurate way to define it, and the different formulations found in literature to calculate it. After several comparisons ... More
Simulations and plans for possible DLA experiments at SINBADJan 23 2018In this work we present the outlines of possible experiments for dielectric laser acceleration (DLA) of ultra-short relativistic electron bunches produced by the ARES linac, currently under construction at the SINBAD facility (DESY Hamburg). The experiments ... More
Ultra-High Brightness Electron Beams from Very-High Field Cryogenic Radio-frequency Photocathode SourcesJan 21 2018Recent investigations of RF copper structures operated at cryogenic temperatures performed by a SLAC-UCLA collaboration have shown a dramatic increase in the maximum surface electric field, to 500 MV/m. We examine use of these fields to enable very high ... More
Muon intensity increase by wedge absorbers for low-e muon experimentsJan 19 2018Low energy muon experiments such as mu2e and g-2 have a limited energy spread acceptance. Following techniques developed in muon cooling studies and the MICE experiment, the number of muons within the desired energy spread can be increased by the matched ... More
A Laser-Plasma Positron Accelerator using Particle-Shower Plasma-Wave interactionsJan 19 2018An all-optical laser-plasma positron accelerator is introduced and modeled using the interaction of laser-driven particle-showers with laser-driven electron plasma-waves. The principle uncovered here shows the trapping and acceleration of positrons that ... More
Recent results at SPARC_LABJan 18 2018The current activity of the SPARC_LAB test-facility is focused on the realization of plasma-based acceleration experiments with the aim to provide accelerating field of the order of several GV/m while maintaining the overall quality (in terms of energy ... More
Helical Undulator Based on Partial Redistribution of Uniform Magnetic FieldJan 16 2018A new type of helical undulator based on redistribution of magnetic field of a solenoid by ferromagnetic helix has been proposed and studied both in theory and experiment. Such undulators are very simple and efficient for promising sources of coherent ... More
Transverse mode coupling instability of the bunch with oscillating wake field and space chargeJan 12 2018Jan 22 2018Transverse mode coupling instability of a single bunch caused by oscillating wake field is considered in the paper. The instability threshold is found at different frequencies of the wake with space charge tune shift taken into account. The wake phase ... More
Gas cell density characterization for laser wakefield accelerationJan 12 2018In the design of laser plasma electron injectors for multi-stage laser driven wakefield accelerators, the control of plasma density is a key element to stabilize the acceleration process. A cell with variable parameters is used to confine the gas and ... More
Wake fields effects in dielectric capillaryJan 12 2018Plasma wake-field acceleration experiments are performed at the SPARC LAB test facility by using a gas-filled capillary plasma source composed of a dielectric capillary. The electron can reach GeV energy in a few centimeters, with an accelerating gradient ... More
Activation assessment of the soil around the ESS accelerator tunnelJan 11 2018Activation of the soil surrounding the ESS accelerator tunnel calculated by the MARS15 code is presented. A detailed composition of the soil, that comprises about 30 different chemical elements, is considered. Spatial distributions of the produced activity ... More
Nano-machining, surface analysis and emittance measurements of a copper photocathode at SPARC_LABJan 11 2018R\&D activity on Cu photocathodes is under development at the SPARC\_LAB test facility to fully characterize each stage of the photocathode "life" and to have a complete overview of the photoemission properties in high brightness photo-injectors. The ... More
Phase Measurement for Driven Spin Oscillations in a Storage RingJan 10 2018Jan 23 2018This paper reports the first simultaneous measurement of the horizontal and vertical components of the polarization vector in a storage ring under the influence of a radio frequency (rf) solenoid. The experiments were performed at the Cooler Synchrotron ... More
Gamma Radiation Spectra of 1200 MeV Electrons in Thick Beryllium, Silicon, and Tungsten Single CrystalsJan 09 2018Gamma radiation spectra of 1200 MeV electrons in the single crystals of the beryllium 1.2 mm thick, silicon 1.5 mm and 15.0 mm thick and tungsten 1.18 mm thick along of the crystallographic axes were measured. Also spectral-angular distributions of gamma ... More
RF injector design studies for the trailing witness bunch for a plasma-based user facilityJan 09 2018Jan 16 2018The interest in plasma-based accelerators as drivers of user facilities is growing worldwide thanks to its compactness and reduced costs. In this context the EuPRAXIA collaboration is preparing a conceptual design report for a multi-GeV plasma-based accelerator ... More
Status and Objectives of the Dedicated Accelerator R&D Facility "SINBAD" at DESYJan 09 2018We present a status update on the dedicated R\&D facility SINBAD which is currently under construction at DESY. The facility will host multiple independent experiments on the acceleration of ultra-short electron bunches and novel, high gradient acceleration ... More
Middle Infrared and THz Sources at AREALJan 09 2018AREAL (Advanced Research Electron Accelerator Laboratory) is an electron linear accelerator with a laser driven RF gun constructed at CANDLE Synchrotron Research Institute. After the successful operation of the gun section at 5 MeV, a program of facility ... More
Warp-X: a new exascale computing platform for beam-plasma simulationsJan 08 2018Turning the current experimental plasma accelerator state-of-the-art from a promising technology into mainstream scientific tools depends critically on high-performance, high-fidelity modeling of complex processes that develop over a wide range of space ... More
Radiation of Channeled Positrons in Ultrasonic WaveJan 08 2018In the classical approximation, we examine the problem of radiation by channeled positrons in the field of a longitudinal ultrasonic wave when the condition of parametric resonance is satisfied. We show that in the case of planar channeling the intensity ... More
Initial Beam Dynamics Simulations of a High-Average-Current Field-Emission Electron Source in a Superconducting RadioFrequency GunJan 06 2018High-power electron beams are sought-after tools in support to a wide array of societal applications. This paper investigates the production of high-power electron beams by combining a high-current field-emission electron source to a superconducting radio-frequency ... More
Pressurized rf cavities in ionizing beamsJan 05 2018A muon collider or Higgs factory requires significant reduction of the six dimensional emittance of the beam prior to acceleration. One method to accomplish this involves building a cooling channel using high pressure gas filled radio frequency cavities. ... More
Influence of the vertical closed orbit distortions on accuracy of the energy calibration done by resonant depolarization techniqueJan 04 2018The series of the experiments on precise mass measurement of $J/\Psi$-, $\Psi'$- mesons have been performed in 2002-2004. Energy calibration has been done with the help of the resonant depolarization technique. The present paper discusses the influence ... More
Optical design for increased interaction length in a high gradient dielectric laser acceleratorJan 03 2018We present a methodology for designing and measuring pulse front tilt in an ultrafast laser for use in dielectric laser acceleration. Previous research into dielectric laser accelerating modules has focused on measuring high accelerating gradients in ... More
Overview of the CLEAR plasma lens experimentJan 03 2018Feb 08 2018Discharge capillary-based active plasma lenses are a promising new technology for strongly focusing charged particle beams, especially when combined with novel high gradient acceleration methods. Still, many questions remain concerning such lenses, including ... More
Preliminary RF design of an X-band linac for the EuPRAXIA@SPARC_LAB projectJan 02 2018In the framework of the upgrade of the SPARC_LAB facility at INFN-LNF, named EuPRAXIA@SPARC_LAB, a high gradient linac is foreseen. One of the most suitable options is to realize it in X-band. A preliminary design study of both accelerating structures ... More
Hydrodynamic, Optically-Field-Ionized (HOFI) Plasma ChannelsJan 02 2018Jan 04 2018We present experiments and numerical simulations which demonstrate that fully-ionized, low-density plasma channels can be formed by hydrodynamic expansion of plasma columns produced by optical field ionization (OFI). The laser energy required to generate ... More
Coupling of Magneto-Thermal and Mechanical Superconducting Magnet Models by Means of Mesh-Based InterpolationDec 29 2017In this paper we present an algorithm for the coupling of magneto-thermal and mechanical finite element models representing superconducting accelerator magnets. The mechanical models are used during the design of the mechanical structure as well as the ... More
Progress on the design of a perpendicularly biased 2nd harmonic cavity for the Fermilab BoosterDec 27 2017A perpendicularly biased 2nd harmonic cavity is being designed and built for the Fermilab Booster. Its purpose is to flatten the bucket at injection and thus change the longitudinal beam distribution to decrease space charge effects. It can also help ... More
Initial observations of micropulse elongation of electron beams in a SCRF acceleratorDec 27 2017Commissioning at the SCRF accelerator at the Fermilab Accelerator Science and Technology (FAST) Facility has included the implementation of a versatile bunch-length monitor located after the 4-dipole chicane bunch compressor for electron beam energies ... More
Laser Driving Highly Collimated $γ$-ray Pulses for the Generation of $μ^-μ^+$ and $e^-e^+$ Pairs in $γ-γ$ ColliderDec 24 2017A scheme to generate highly collimated $\gamma$-ray pulse is proposed for the production of muon and electron pairs in $\gamma-\gamma$ collider. The $\gamma$-ray pulse, with high conversion efficiency, can be produced as the result of electron phase-locked ... More
Multi-color, femtosecond $γ$-ray pulse trains driven by comb-like electron beamsDec 22 2017Photon engineering can be exploited to control the nonlinear evolution of the drive pulse in a laser-plasma accelerator (LPA), offering new avenues to tailor electron beam phase space on a femtosecond time scale. One promising option is to drive an LPA ... More
Frequency dependence of trapped flux sensitivity in SRF cavitiesNov 16 2017In this letter, we present the frequency dependence of the vortex surface resistance of bulk niobium accelerating cavities as a function of different state-of-the-art surface treatments. Higher flux surface resistance per amount of trapped magnetic field ... More
A 2-D Finite-Element Model for Electro-Thermal Transients in Accelerator MagnetsOct 03 2017Dec 05 2017Superconducting accelerator magnets require sophisticated monitoring and means of protection due to the large energy stored in the magnetic field. Numerical simulations play a crucial role in understanding transient phenomena occurring within the magnet, ... More
Simultaneous Detection of Longitudinal and Transverse Bunch Signals at the KARA Storage RingSep 26 2017Time-resolved measurements of the energy spread, the longitudinal bunch profile together with studies of the emitted coherent synchrotron radiation allow investigations of the beam dynamics of synchrotron light sources. The simultaneous turn-by-turn measurement ... More
Enhancing laser-driven proton acceleration by using micro-pillar arrays at high drive energySep 19 2017The interaction of micro- and nano-structured target surfaces with high-power laser pulses is being widely investigated for its unprecedented absorption efficiency. We have developed vertically aligned metallic micro-pillar arrays for laser-driven proton ... More
Excitation and Control of Plasma Wakefields by Multiple Laser PulsesAug 14 2017We demonstrate experimentally the resonant excitation of plasma waves by trains of laser pulses. We also take an important first step to achieving an energy recovery plasma accelerator by showing that unused wakefield energy can be removed by an out-of-resonance ... More
Intensity limits of the PSI Injector II cyclotronJul 25 2017We investigate limits on the current of the PSI Injector II high intensity separate-sector isochronous cyclotron, in its present configuration and after a proposed upgrade. Accelerator Driven Subcritical Reactors, neutron and neutrino experiments, and ... More
Coherent modes of X-ray beams emitted by undulators in new storage ringsJun 14 2017Synchrotron radiation emitted by electrons passing through an undulator placed in a storage ring is decomposed in coherent modes. The case of ultimate storage rings where the electron emittance is comparable to the emittance of the photon fan is analyzed ... More
High Flux Femtosecond X-ray Emission from the Electron-Hose Instability in Laser Wakefield AcceleratorsMay 02 2017Bright and ultrashort duration X-ray pulses can be produced by through betatron oscillations of electrons during Laser Wakefield Acceleration (LWFA). Our experimental measurements using the \textsc{Hercules} laser system demonstrate a dramatic increase ... More
A new concept multi-stage Zeeman deceleratorFeb 14 2017Mar 23 2017We present a new concept for a multi-stage Zeeman decelerator that is optimized particularly for applications in molecular beam scattering experiments. The decelerator consists of a series of alternating hexapoles and solenoids, that effectively decouple ... More
RF Measurements of the New TOTEM Roman PotDec 07 2016The TOTEM experiment has been designed to measure the total proton-proton cross section and to study the elastic and diffractive scattering at the LHC energy. The measurement requires detecting protons at distances as small as 1 mm from the beam center: ... More
Stimulated X-ray Raman scattering in Free Electron Lasers with incoherent spectrumDec 06 2016The single-pulse spectrum of self-amplified spontaneous emission (SASE) free electron lasers (FELs) is characterized by random fluctuations in frequency. The typical spectrum bandwidth for a hard x-ray FEL is in the range of 10-20 eV and is comparable ... More
Giant Terahertz Pulses Generated by Relativistic Beam in a Dielectric ChannelDec 06 2016We analyze the electromagnetic field of a short relativistic electron beam propagating in a round, hollow dielectric channel. We show that if the beam propagates with an offset relative to the axis of the channel, in a steady state, its electromagnetic ... More
Kinetics of relativistic electrons passing through quasi--periodic fieldsDec 05 2016We report a novel method for evaluating the energy spectrum of electrons emitting hard x-rays and gamma-rays in undulators and Compton sources. The method takes into account the quantum nature of recoils undergone by the electrons emitting high energy ... More
Development of a Watt-level Gamma-Ray Source based on High-Repetition-Rate Inverse Compton ScatteringDec 05 2016A high-brilliance ($\sim10^{24}$~photon.s$^{-1}$.mm$^{-2}$.mrd$^{-2}$/0.1\%) gamma-ray source experiment is currently being planned at Fermilab ($E_\gamma\simeq 1.1$~MeV)~[1]. The source implements a high-repetition-rate inverse Compton scattering by ... More
The BRAN luminosity detectors for the LHCDec 05 2016This paper describes the several phases which led, from the conceptual design, prototyping, construction and tests with beam, to the installation and operation of the BRAN (Beam RAte of Neutrals) relative luminosity monitors for the LHC. The detectors ... More
Quantum Theory of Amplification in RSDec 04 2016The equations for the amplitudes of transition probabilities are found. The resonance frequency of the system is calculated. It is shown the dependence of the resonance frequency on the initial transverse coordinate of an electron. This dependence is ... More
Geant4 simulations of the lead fluoride calorimeterNov 30 2016In this paper we simulate the emission by charged particles in complex structures with help of Geant4. We take into account Cherenkov radiation, transition radiation, bremsstrahlung, pair production and other accompanying processes. As an application ... More
Positron ChannelingNov 29 2016The possibility of channeling the low-energy relativistic positrons around separate crystallographic axes with coaxial symmetry of negative ions in some types of crystals is shown. The process of annihilation of positrons with electrons of medium was ... More
Wakefields of a Beam near a Single Plate in a Flat DechirperNov 29 2016We give formulas for the longitudinal, transverse, and quad point charge wakes for a short bunch of electrons passing by one plate of a flat dechirper.
The Nonlinear Theory of FELNov 28 2016The nonlinear theory of relyativistic strophotron is developed. Classical equations of motion are averaged over fast oscillations. The slow motion phase and saturation parameter are found different from usual undulator oscillation parameters. In the strong ... More
Some Aspects of FELWINov 28 2016A threshold condition for amplification without inversion in a free-electron laser without inversion (FELWI) is determined. This condition is found to be too severe for the effect to be observed in an earlier suggested scheme because a threshold intensity ... More
Multipacting studies of beta_g=0.61 and beta_g =0.9, 650 MHz Elliptical SRF CavitiesNov 27 2016Multipacting is seen as a performance limiting phenomenon for the superconducting radio frequency (SRF) cavities. Numerical simulations are essential to pre-empt the experimentally observed multipacting conditions. Readily available codes(e.g. FISHPACT, ... More
The Amplification in FEL with Inhomogeneous Magnetic FieldNov 27 2016The gain in a plane wiggler with inhomogeneous magnetic field is calculated.. It is shown, that the account of inhomogenity of the magnetic field leads to appearance of additional peaks in the amplification
Velocity Dispersion of Correlated Energy Spread Electron Beams in the Free Electron LaserNov 24 2016The effects of a correlated linear energy/velocity chirp in the electron beam in the FEL, and how to compensate for its effects by using an appropriate taper (or reverse-taper) of the undulator magnetic field, is well known. The theory, as described thus ... More
Relativistic Stern-Gerlach Deflection: Hamiltonian FormulationNov 22 2016A Hamiltonian formalism is employed to elucidate the effects of the Stern-Gerlach force on beams of relativistic spin-polarized particles, for passage through a localized region with a static magnetic or electric field gradient. The problem of the spin-orbit ... More
Collisionless electrostatic shock formation and ion acceleration in intense laser interactions with near critical density plasmasNov 21 2016Laser-driven collisonless electrostatic shock formation and the subsequent ion acceleration have been studied in near critical density plasmas. Particle-in-cell simulations show that both the speed of laser-driven collisionless electrostatic shock and ... More
The Spontaneous Radiation of Electrons in a Plane Wiggler with Inhomogeneous Magnetic FieldNov 20 2016The spectral distribution of spontaneous emission of electrons moving in a plane wiggler with inhomogeneous magnetic field is calculated. We show that electrons do complicated motion consisting of slow(strophotron) and fast(undulator) parts. The equations ... More
Using LSTM recurrent neural networks for detecting anomalous behavior of LHC superconducting magnetsNov 18 2016The superconducting LHC magnets are coupled with an electronic monitoring system which records and analyses voltage time series reflecting their performance. A currently used system is based on a range of preprogrammed triggers which launches protection ... More
Accurate modeling of plasma acceleration with arbitrary order pseudo-spectral particle-in-cell methodsNov 17 2016Particle in Cell (PIC) simulations are a widely used tool for the investigation of both laser- and beam-driven plasma acceleration. It is a known issue that the beam quality can be artificially degraded by numerical Cherenkov radiation (NCR) resulting ... More
Accurate modeling of plasma acceleration with arbitrary order pseudo-spectral particle-in-cell methodsNov 17 2016Mar 29 2017Particle in Cell (PIC) simulations are a widely used tool for the investigation of both laser- and beam-driven plasma acceleration. It is a known issue that the beam quality can be artificially degraded by numerical Cherenkov radiation (NCR) resulting ... More
Concentration of the velocity distribution of pulsed neutron beamsNov 17 2016The velocity of neutrons from a pulsed neutron source is well-defined as a function of their arrival time. Electromagnetic neutron accelerator/decelerator synchronized with the neutron time-of-flight is capable of selectively changing the neutron velocity ... More
A Novel Collimation Method for Large Hadron CollidersNov 16 2016This paper proposes a novel collimation method for large hadron colliders by arranging betatron and momentum collimation systems in the same insertion to improve the overall cleaning efficiency. The method has the potential of avoiding beam losses at ... More
A Parallelized Vlasov-Fokker-Planck-Solver for Desktop PCsNov 16 2016The numerical solution of the Vlasov-Fokker-Planck equation is a well established method to simulate the dynamics, including the self-interaction with its own wake field, of an electron bunch in a storage ring. In this paper we present Inovesa, a modularly ... More
A Parallelized Vlasov-Fokker-Planck-Solver for Desktop PCsNov 16 2016Nov 17 2016The numerical solution of the Vlasov-Fokker-Planck equation is a well established method to simulate the dynamics, including the self-interaction with its own wake field, of an electron bunch in a storage ring. In this paper we present Inovesa, a modularly ... More
Laser-Induced Linear Electron Acceleration in Free SpaceNov 16 2016Linear acceleration in free space is a topic that has been studied for over 20 years, and its ability to eventually produce high-quality, high energy multi-particle bunches has remained a subject of great interest. Arguments can certainly be made that ... More
An MDM Spin Transparent Quadrupole for Storage Ring based EDM SearchNov 15 2016A storage ring provides an attractive option for directly measuring the electric dipole moment~(EDM) of charged particles. To reach a sensitivity of 10^-29 e x cm, it is critical to mitigate the systematic errors from all sources. This daunting task is ... More
Phase Jump Method for Efficiency Enhancement in Free-Electron LasersNov 15 2016The efficiency of a free-electron laser can be enhanced by sustaining the growth of the radiation power beyond the initial saturation. One notable method is undulator tapering, which involves the variation of the gap height and/or the period along the ... More
Channeling and Radiation of 855 MeV Electrons and Positrons in Straight and Bent Tungsten (110) CrystalsNov 15 2016Planar channeling of 855 MeV electrons and positrons in straight and bent tungsten (110) crystal is simulated by means of the \MBNExplorer software package. The results of simulations for a broad range of bending radii are analyzed in terms of the channel ... More
The Fast Linear Accelerator Modeling Engine for FRIB Online Model ServiceNov 14 2016Commissioning of a large accelerator facility like FRIB needs support from an online beam dynamics model. Considering the new physics challenges of FRIB such as modeling of non-axisymmetric superconducting RF cavities and multi-charge state acceleration, ... More
Diffusion of Hydrogen in Proton Implanted Silicon: Dependence on the Hydrogen ConcentrationNov 14 2016The reported diffusion constants for hydrogen in silicon vary over six orders of magnitude. This spread in measured values is caused by the different concentrations of defects in the silicon that has been studied. Hydrogen diffusion is slowed down as ... More
Diffusion of Hydrogen in Proton Implanted Silicon: Dependence on the Hydrogen ConcentrationNov 14 2016Dec 05 2016The reported diffusion constants for hydrogen in silicon vary over six orders of magnitude. This spread in measured values is caused by the different concentrations of defects in the silicon that has been studied. Hydrogen diffusion is slowed down as ... More
Diffusion of Hydrogen in Proton Implanted Silicon: Dependence on the Hydrogen ConcentrationNov 14 2016Nov 28 2016The reported diffusion constants for hydrogen in silicon vary over six orders of magnitude. This spread in measured values is caused by the different concentrations of defects in the silicon that has been studied. Hydrogen diffusion is slowed down as ... More
Infrared Radiation from Rough SurfaceNov 13 2016We consider generation of diffusive radiation by a charged particle passing through a random stack of plates in the infrared region. Diffusive radiation originates due to multiple scattering of pseudophotons on the plates. To enhance the radiation intensity ... More
Effects of Laser Pulse Heating of Copper Photocathodes on High-brightness Electron Beam Production at Blowout RegimeNov 12 2016Producing high-brightness and high-charge (>100 pC) electron bunches at blowout regime requires ultrashort laser pulse with high fluence. The effects of laser pulse heating of the copper photocathode are analyzed in this paper. The electron and lattice ... More
Laser Pulsing in Linear Compton ScatteringNov 12 2016Previous work on calculating energy spectra from Compton scattering events has either neglected considering the pulsed structure of the incident laser beam, or has calculated these effects in an approximate way subject to criticism. In this paper, this ... More
Relativistic Stern-Gerlach DeflectionNov 11 2016Modern advances in polarized beam control should make it possible to accurately measure Stern-Gerlach (S-G) deflection of relativistic beams. Toward this end a relativistically covariant S-G formalism is developed that respects the opposite behavior under ... More
Extreme diffusion limited electropolishing of niobium radiofrequency cavitiesNov 10 2016Deeply modulated, continuous, diffusion-limited current waveforms for electropolishing niobium single-cell elliptical radiofrequency cavities are reliably and repeatedly achieved at Fermilab. Details of the technique and cavity test results are reported ... More
Extreme diffusion limited electropolishing of niobium radiofrequency cavitiesNov 10 2016Nov 17 2016A deeply modulated, regular, continuous, oscillating current waveform is reliably and repeatably achieved during electropolishing of niobium single-cell elliptical radiofrequency cavities. Details of the technique and cavity test results are reported ... More