A hot-spare injector for the APS linac

Lewellen, John W.; Thompson, K.; Jagger, John; Milton, S. V.; Nassiri, A.; Borland, M.; Mangra, D.

doi:10.1109/pac.1999.794334

Cited by 12 publications

(7 citation statements)

References 4 publications

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“…Our interest was to measure the charge of each micropulse within the macropulse structure from the chopper-gated [4], TC-rf gun [5][6][7]. The extraction of charge from the TC rf gun involves high-power rf applied to the cathode; thus, the extracted charge comes in a series of micropulses.…”

Section: Introductionmentioning

confidence: 99%

Microbunching of thermionic cathode rf gun beams in the Advanced Photon Source s-band linac

Dooling,

Brill,

Lobach

et al. 2024

J. Phys.: Conf. Ser.

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We report on measurements of beams from thermionic cathode (TC) rf guns in the Advanced Photon Source S-Band Linac. These measurements include the macropulse out of both new and existing TC guns as well as the observation of microbunching within the micropulses of these beams. A gun chopper limits the macropulse FWHM duration to the 10-ns range. Our objectives were to analyse the new TC gun and investigate microbunching within a TC-rf-gun-generated beam. Our diagnostics elucidated longitudinal beam structures from the ns to the fs time scales. Coherent transition radiation (CTR) interferometers responding to far-infrared wavelengths were employed after each compression stage to provide the autocorrelations of the sub-ps micropulse durations. The first compression stage is an alpha magnet and the second a chicane. A CCD camera was used to image the beam via optical transition radiation from an Al screen at the end of the linac and also employed to measure coherent optical transition radiation (COTR) in the visible range. The COTR diagnostic observations, implying microbunching on a fs time scale, are presented and compared with a longitudinal space-charge impedance model.

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Section: Introductionmentioning

confidence: 99%

Microbunching of thermionic cathode rf gun beams in the Advanced Photon Source s-band linac

Dooling,

Brill,

Lobach

et al. 2024

J. Phys.: Conf. Ser.

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“…The goal of the experiment is to demonstrate record high single pass energy extraction efficiency in the strongly tapered seeded regime at Ultra-Violet (UV) wavelengths. The program is the result of a collaborative effort of UCLA, RadiaBeam, Argonne National Laboratory and RadiaSoft and has been developed based on the possibility to use the high brightness beam from the Advanced Photon Source (APS) linac, an electron accelerator with energy up to 500 MeV, and nominally operated around 350 MeV [29]. Compared to previous tapered undulator experiments, the main novelties in the setup are the use of a strongly tapered helical undulator to provide continuous coupling with circularly polarized electromagnetic waves and a novel focusing scheme based on the implementation of a quadrupole doublet in the undulator break section to maintain very high beam density and maximize the radiation generation.…”

Section: Introductionmentioning

confidence: 99%

Tapered helical undulator system for high efficiency energy extraction from a high brightness electron beam

Park,

Agustsson,

Berg

et al. 2021

Preprint

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In this paper we discuss the design choices and construction strategy of the tapered undulator system designed for a high energy extraction efficiency experiment in the ultraviolet region of the electromagnetic spectrum planned for installation at the Argonne National Laboratory Linac Extension Area (LEA) beamline. The undulator is comprised of 4 sections pure permanent magnet Halbach array separated by short break sections, each one of them housing a focusing quadrupole doublet and a phase shifter. The quadrupoles use a novel hybrid design which allows one to vary the gradient and match the beam transversely. The undulator tapering profile is optimized to maximize the energy conversion efficiency from a 343 MeV 1 kA beam into coherent 257.5 nm radiation taking into account the longitudinal current profile generated by the linac.

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“…Prior to the arrival of these injectors, the APS was using one firstgeneration (1G) and one second-generation (2G) rf gun. Each alternated in the role of main injector and hot spare for reliable storage ring injection [1]. Both provided consistent and sufficient beam for our needs over the years they have been in service.…”

Section: Introductionmentioning

confidence: 99%

A rationalized approach to thermionic rf gun design

Beczek

Lewellen²,

Nassiri³

et al.

PACS2001. Proceedings of the 2001 Particle Accelerator Conference (Cat. No.01CH37268)

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The Advanced Photon Source (APS), in conjunction with Advanced Electronics Technologies Associates (AET), is developing newly designed thermionic-cathode rf guns to replace our aging (circa 1992) guns. Each of the three third-generation injectors will meet or exceed the present high-performance electron beam of its secondgeneration predecessor. Moreover, the new injector design addresses the historical difficulties of maintenance, reliability, and sparse documentation associated with the previous injectors. Engineering design improvements and required performance of the guns will be presented following a brief examination of the APS secondgeneration guns for comparison.

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A hot-spare injector for the APS linac

Cited by 12 publications

References 4 publications

Microbunching of thermionic cathode rf gun beams in the Advanced Photon Source s-band linac

Microbunching of thermionic cathode rf gun beams in the Advanced Photon Source s-band linac

Tapered helical undulator system for high efficiency energy extraction from a high brightness electron beam

A rationalized approach to thermionic rf gun design

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