RF properties of a X-band hybrid photoinjector

Spataro, B.; Valloni, Alessandra; Alesini, D.; Biancacci, Nicolò; Faillace, L.; Ficcadenti, L.; Fukusawa, A.; Lancia, L.; Migliorati, M.; Morelli, Flavio; Mostacci, A.; O’Shea, Brendan; Palumbo, L.; Rosenzweig, James; Yakub, A.

doi:10.1016/j.nima.2011.04.057

Cited by 19 publications

(10 citation statements)

References 10 publications

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“…The beam line includes a 105 cm long X-band acceleration section (T105) which takes the electron beam up to 100 MeV and an electron beam measurement station. Other X-band photoinjectors such as the UCLA hybrid gun [37] will be characterized at this facility.…”

Section: F Slac Testingmentioning

confidence: 99%

Modeling and design of anX-band rf photoinjector

Marsh

Albert

Anderson

et al. 2012

Phys. Rev. ST Accel. Beams

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A design for an X-band rf photoinjector that was developed jointly by SLAC National Accelerator Laboratory (SLAC) and Lawrence Livermore National Laboratory (LLNL) is presented. The photoinjector is based around a 5.59 cell rf gun that has state-of-the-art features including: elliptical contoured irises; improved mode separation; an optimized initial half cell length; a racetrack input coupler; and coupling that balances pulsed heating with cavity fill time. Radio-frequency and beam dynamics modeling have been done using a combination of codes including PARMELA, HFSS, IMPACT-T, ASTRA, and the ACE3P suite of codes developed at SLAC. The impact of lower gradient operation, magnet misalignment, solenoid multipole errors, beam offset, mode beating, wakefields, and beam line symmetry have been analyzed and are described. Fabrication and testing plans at both LLNL and SLAC are discussed.

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Section: F Slac Testingmentioning

confidence: 99%

Modeling and design of anX-band rf photoinjector

Marsh

Albert

Anderson

et al. 2012

Phys. Rev. ST Accel. Beams

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“…Also, at high power, circulators used to protect the rf power sources are difficult to realize. One may avoid rf reflections by use of innovative gun designs, such as the hybrid standing-traveling wave [121,122] and traveling wave [123] photoinjectors. These solutions are attractive for other reasons, including experimentally demonstrated inherent velocity bunching for ultrashort beam creation at low energy in the hybrid [124]).…”

Section: Prospects For Higher Rf Frequency Higher Field Photoinjmentioning

confidence: 99%

Next generation high brightness electron beams from ultrahigh field cryogenic rf photocathode sources

Rosenzweig

Cahill

Dolgashev

et al. 2019

Phys. Rev. Accel. Beams

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Recent studies of the performance of radio-frequency (rf) copper cavities operated at cryogenic temperatures have shown a dramatic increase in the maximum achievable surface electric field. We propose to exploit this development to enable a new generation of photoinjectors operated at cryogenic temperatures that may attain, through enhancement of the launch field at the photocathode, a significant increase in fivedimensional electron beam brightness. We present detailed studies of the beam dynamics associated with such a system, by examining an S-band photoinjector operated at 250 MV=m peak electric field that reaches normalized emittances in the 40 nm-rad range at charges (100-200 pC) suitable for use in a hard x-ray free-electron laser (XFEL) scenario based on the LCLS. In this case, we show by start-to-end simulations that the properties of this source may give rise to high efficiency operation of an XFEL, and permit extension of the photon energy reach by an order of magnitude, to over 80 keV. The brightness needed for such XFELs is achieved through low source emittances in tandem with high current after compression. In the XFEL examples analyzed, the emittances during final compression are preserved using microbunching techniques. Extreme low emittance scenarios obtained at pC charge, appropriate for significantly extending temporal resolution limits of ultrafast electron diffraction and microscopy experiments, are also reviewed. While the increase in brightness in a cryogenic photoinjector is mainly due to the augmentation of the emission current density via field enhancement, further possible increases in performance arising from lowering the intrinsic cathode emittance in cryogenic operation are also analyzed. Issues in experimental implementation, including cavity optimization for lowering cryogenic thermal dissipation, external coupling, and cryocooler system, are discussed. We identify future directions in ultrahigh field cryogenic photoinjectors, including scaling to higher frequency, use of novel rf structures, and enabling of an extremely compact hard x-ray FEL.

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“…Symbol Value Normalized Emittance (split) Field Gradient of Skew Quads (1-cm thick) can generate a short beam as well as low emittance beam, as it has a combined structure of the RF gun and traveling wave velocity buncher [9] (Figure 8). We have performed the beam dynamics simulations, and the 3D RF design has been done by using ANSYS HFSS [10].…”

Section: Parametermentioning

confidence: 99%

An asymmetric emittance electron source for the GALAXIE dielectric-laser accelerator injector

Valloni¹,

Cahill²,

Fukusawa³

et al. 2013

AIP Conference Proceedings

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Abstract. The GALAXIE project is a program to develop an all-optical, very high field accelerator and undulator integrated SASE FEL system based on dielectric laser-excited structures that support >GV/m fields. These structures are very wide in one direction to allow adequate charge given beam loading considerations, but also having small (subwavelength) apertures in the narrow direction. Such small vertical dimensions yield strict restrictions on the emittance in this direction, while no such constraint exists in the wide transverse direction. However, the overall beam brightness is restricted by the performance requirements on the FEL. To meet these demands, we are studying a very high field gun with a magnetized cathode, yielding a beam with angular momentum content. This beam is then subject to a skew-quad triplet that splits the emittances; this process is reversed to give a round beam after acceleration. This symmetric emittance beam avoids gain-degrading multiple-transverse-mode operation of the FEL, which also demands that the effects of the angular momentum in the beam be mitigated. In this paper we discuss the RF design of an X-band gun to be operated at ~200 MV/m peak field giving a 1 pC magnetized beam with unprecedented brightness. We examine the design of the focusing and skew-quad systems, investigating the associated beam dynamics and efficacy of emittance splitting.

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RF properties of a X-band hybrid photoinjector

Cited by 19 publications

References 10 publications

Modeling and design of anX-band rf photoinjector

Modeling and design of anX-band rf photoinjector

Next generation high brightness electron beams from ultrahigh field cryogenic rf photocathode sources

An asymmetric emittance electron source for the GALAXIE dielectric-laser accelerator injector

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