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Author (up) Andrews, H.L.; Taheri, F.B.; Barros, J.; Bartolini, R.; Bharadwaj, V.; Clarke, C.; Delerue, N.; Doucas, G.; Fuster-Martinez, N.; Vieille-Grosjean, M.; Konoplev, I.V.; Labat, M.; Le Corre, S.; Perry, C.; Reichold, A.; Stevenson, S.
Title Reconstruction of the time profile of 20.35 GeV, subpicosecond long electron bunches by means of coherent Smith-Purcell radiation Type Journal Article
Year 2014 Publication Physical Review Special Topics-Accelerators and Beams Abbreviated Journal Phys. Rev. Spec. Top.-Accel. Beams
Volume 17 Issue 5 Pages 052802 - 13pp
Keywords
Abstract We have used coherent Smith-Purcell radiation (cSPr) in order to determine the temporal profile of sub-ps long electron bunches at the Facility for Advanced Accelerator Experimental Tests, at SLAC. The measurements reported here were carried out in June 2012 and April 2013. The rms values for the bunch length varied between 356 to 604 fs, depending on the accelerator settings. The resolution of the system was limited by the range of detectable wavelengths which was, in turn, determined by the choice of the grating periods used in these experiments and the achievable beam-grating separation. The paper gives the details of the various steps in the reconstruction of the time profile and discusses possible improvements to the resolution. We also present initial measurements of the polarization properties of cSPr and of the background radiation.
Address [Andrews, H. L.] LANL, Los Alamos, NM 87545 USA, Email: g.doucas@physics.ox.ac.uk
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-4402 ISBN Medium
Area Expedition Conference
Notes WOS:000336654500006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1808
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Author (up) Fuster-Martinez, N.; Assmann, R.W.; Bruce, R.; Giovannozzi, M.; Hermes, P.; Mereghetti, A.; Mirarchi, D.; Redaelli, S.; Wenninger, J.
Title Beam-based aperture measurements with movable collimator jaws as performance booster of the CERN Large Hadron Collider Type Journal Article
Year 2022 Publication European Physical Journal Plus Abbreviated Journal Eur. Phys. J. Plus
Volume 137 Issue 3 Pages 305 - 20pp
Keywords
Abstract The beam aperture of a particle accelerator defines the clearance available for the circulating beams and is a parameter of paramount importance for the accelerator performance. At the CERN Large Hadron Collider (LHC), the knowledge and control of the available aperture is crucial because the nominal proton beams carry an energy of 362 MJ stored in a superconducting environment. Even a tiny fraction of beam losses could quench the superconducting magnets or cause severe material damage. Furthermore, in a circular collider, the performance in terms of peak luminosity depends to a large extent on the aperture of the inner triplet quadrupoles, which are used to focus the beams at the interaction points. In the LHC, this aperture represents the smallest aperture at top-energy with squeezed beams and determines the maximum potential reach of the peak luminosity. Beam-based aperture measurements in these conditions are difficult and challenging. In this paper, we present different methods that have been developed over the years for precise beam-based aperture measurements in the LHC, highlighting applications and results that contributed to boost the operational LHC performance in Run 1 (2010-2013) and Run 2 (2015-2018)
Address [Fuster-Martinez, N.] Inst Fis Corpuscular CSIC UV, Valencia, Spain, Email: nuria.fuster@ific.uv.es
Corporate Author Thesis
Publisher Springer Heidelberg Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2190-5444 ISBN Medium
Area Expedition Conference
Notes WOS:000764734000003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5160
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Author (up) Fuster-Martinez, N.; Bruce, R.; Hofer, M.; Persson, T.; Redaelli, S.; Tomas, R.
Title Aperture measurements with ac dipoles and movable collimators in the Large Hadron Collider Type Journal Article
Year 2022 Publication Physical Review Accelerators and Beams Abbreviated Journal Phys. Rev. Accel. Beams
Volume 25 Issue 10 Pages 101002 - 13pp
Keywords
Abstract This paper presents a first experimental demonstration of a new nondestructive method for aperture measurements based on ac dipoles. In high intensity particle colliders, such as the CERN Large Hadron Collider (LHC), aperture measurements are crucial for a safe operation while optimizing the optics in order to reduce the size of the colliding beams and hence increase the luminosity. In the LHC, this type of measurements became mandatory during beam commissioning and the current method used is based on the destructive blowup of bunches using a transverse damper. The new method presented in this paper uses the ac-dipole excitation to generate adiabatic forced oscillations of the beam in order to create losses to identify the smallest aperture in the machine without blowing up the beam emittance. A precise and tuneable control of the oscillation amplitude enables the beams to be reused for several aperture measurements, as well as for other subsequent commissioning activities. Measurements performed with the new method are presented and compared with the current LHC transverse damper method for two different beam energies and two different operational optics.
Address [Fuster-Martinez, N.] CSIC UV, Inst Fis Corpuscular, Valencia 46908, Spain, Email: nuria.fuster@ific.uv.es
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes WOS:000875736400001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5397
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Author (up) Gonzalez-Iglesias, D.; Aksoy, A.; Esperante, D.; Gimeno, B.; Latina, A.; Boronat, M.; Blanch, C.; Fuster-Martinez, N.; Martinez-Reviriego, P.; Martin-Luna, P.; Fuster, J.
Title X-band RF photoinjector design for the CompactLight project Type Journal Article
Year 2021 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume 1014 Issue Pages 165709 - 10pp
Keywords Photoinjector; X-band; Electron sources; Free electron laser; Beam generation
Abstract RF photoinjectors have been under development for several decades to provide the high-brightness electron beams required for X-ray Free Electron Lasers. This paper proposes a photoinjector design that meets the Horizon 2020 CompactLight design study requirements. It consists of a 5.6-cell, X-band (12 GHz) RF gun, an emittance-compensating solenoid and two X-band traveling-wave structures that accelerate the beam out of the space-charge-dominated regime. The RF gun is intended to operate with a cathode gradient of 200 MV/m, and the TW structures at a gradient of 65 MV/m. The shape of the gun cavity cells was optimized to reduce the peak electric surface field. An assessment of the gun RF breakdown likelihood is presented as is a multipacting analysis for the gun coaxial coupler. RF pulse heating on the gun inner surfaces is also evaluated and beam dynamics simulations of the 100 MeV photoinjector are summarized.
Address [Gonzalez-Iglesias, D.; Esperante, D.; Gimeno, B.; Boronat, M.; Blanch, C.; Fuster-Martinez, N.; Martinez-Reviriego, P.; Martin-Luna, P.; Fuster, J.] Univ Valencia Consejo Super Invest Cient, Inst Fis Corpuscular IFIC, Calle Catedrat Jose Beltran 2, Valencia 46980, Spain, Email: daniel.gonzalez-iglesias@uv.es
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0168-9002 ISBN Medium
Area Expedition Conference
Notes WOS:000704382900005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4983
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Author (up) Gonzalez-Iglesias, D.; Esperante, D.; Gimeno, B.; Blanch, C.; Fuster-Martinez, N.; Martinez-Reviriego, P.; Martin-Luna, P.; Fuster, J.; Alesini, D.
Title Analysis of the Multipactor Effect in an RF Electron Gun Photoinjector Type Journal Article
Year 2023 Publication IEEE Transactions on Electron Devices Abbreviated Journal IEEE Trans. Electron Devices
Volume 70 Issue 1 Pages 288-295
Keywords Magnetic tunneling; Multipactor effect; photoinjector; RF breakdown; RF gun
Abstract The objective of this work is the evaluation of the risk of suffering a multipactor discharge within an RF electron gun photoinjector. Photoinjectors are a type of source for intense electron beams, which are the main electron source for synchrotron light sources, such as free-electron lasers. The analyzed device consists of 1.6 cells and it has been designed to operate at the S-band. Besides, around the RF gun there is an emittance compensation solenoid, whose magnetic field prevents the growth of the electron beam emittance, and thus the degradation of the properties of the beam. The multipactor analysis is based on a set of numerical simulations by tracking the trajectories of the electron cloud in the cells of the device. To reach this aim, an in-house multipactor code was developed. Specifically, two different cases were explored: with the emittance compensation solenoid assumed to be off and with the emittance compensation solenoid in operation. For both the cases, multipactor simulations were carried out exploring different RF electric field amplitudes. Moreover, for a better understanding of the multipactor phenomenon, the resonant trajectories of the electrons and the growth rate of the electrons population are investigated.
Address [Gonzalez-Iglesias, D.; Esperante, D.; Gimeno, B.; Blanch, C.; Fuster-Martinez, N.; Martinez-Reviriego, P.; Martin-Luna, P.; Fuster, J.] Univ Valencia, Inst Fis Corpuscular IFIC, CSIC, Paterna 46980, Spain, Email: Daniel.Gonzalez-Iglesias@uv.es
Corporate Author Thesis
Publisher 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 0018-9383 ISBN Medium
Area Expedition Conference
Notes WOS:000890813600001 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 5427
Permanent link to this record