Coherent off-axis undulator radiation from short electron bunches

Neuman, C. P.; Graves, W.; O’Shea, P.G.

doi:10.1103/physrevstab.3.030701

Cited by 16 publications

(14 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…(17) has an extra exponent comparing to the formula given in [8]. It accounts for reduction of the CSR intensity in the case of a beam with a large transverse size [10]. Starting with (17) and using (9), we obtain a perturbation in x after the second emittance exchange…”

Section: Figure 3 Relative Emittance Increase As a Function Of The Hmentioning

confidence: 99%

A new type of bunch compressor and seeding of a short-wavelength coherent radiation.

Zholents¹,

Zolotorev²

2011

View full text Add to dashboard Cite

Transverse-to-longitudinal emittance exchange was proposed in [1] as a tool for an effective matching of the electron beam phase space to requirements of a possible application.Here we propose a new purpose, namely, use of two consecutive emittance exchanges equipped with the telescope between them for a bunch compression that can be done without the energy chirp in the electron bunch. In principle it allows to reduce the electron peak current in the linac by moving the bunch compressor to the end of the linac and, thus, to relax collective effects associated with high peak currents. It is also possible to have a split-action compression when the first part is done inside the low-energy part of the linac and the second and final part is done after the linac. We also demonstrate how proposed bunch compressor can be used for frequency upconversion of the energy modulation provided by the laser interacting with the electron beam and thus can prepare a significantly higher frequency seed for seeded free-electron lasers. The same approach can be used for a frequency down-conversion that can be useful for generation of THz radiation.PACS numbers 41.60.Cr, 42.55.Vc 2

show abstract

Section: Figure 3 Relative Emittance Increase As a Function Of The Hmentioning

confidence: 99%

A new type of bunch compressor and seeding of a short-wavelength coherent radiation.

Zholents¹,

Zolotorev²

2011

View full text Add to dashboard Cite

show abstract

“…Specifically, the angular and spectral distributions of the coherent IR radiation outcoupled through the prism can be used to characterize the bunch length and transverse size. Such diagnostics are conceptually similar to the one based on coherent off-axis undulator radiation from short electron bunches [17].…”

Section: Introductionmentioning

confidence: 99%

“…Such diagnostics are particularly desirable for ultrashort low-emittance bunches produced by laser-plasma accelerators. It is well established [17,26,27] that, regardless of the specific mechanism of radiation generation (e.g., synchrotron, transition, or undulator), the spectral intensity of far-field radiation emitted by a bunch of N e can be expressed as the sum of coherent and incoherent components:…”

Section: Accelerator and Beam Diagnostics Applications Of The Swabsicmentioning

confidence: 99%

Prism-coupled surface wave accelerator based on silicon carbide

Neuner

Korobkin

Ferro

et al. 2012

Phys. Rev. ST Accel. Beams

View full text Add to dashboard Cite

A compact, solid-state accelerating structure based on surface waves is proposed and experimentally characterized. The structure, consisting of two SiC layers epitaxially grown on Si slabs and separated from each other by a subwavelength acceleration channel, is shown to support both longitudinal (accelerating) and transverse (deflecting) surface modes. Both modes are experimentally excited and characterized by performing angle-resolved spectroscopy with a wavelength-tunable carbon dioxide laser. Phase velocities of superluminous and subluminous modes are experimentally demonstrated, paving the way for tabletop charged particle acceleration. The same structure can be used for optical characterization of ultrashort electron bunches that generate longitudinal and transverse Cherenkov radiation.

show abstract

“…where ( ) A numerical simulation using this method reveals interesting characteristics of off-axis undulator radiation [1]. In particular, the effect of changes in bunch length on the total radiated energy is calculated for both a Gaussianand a top-hat-shaped bunch.…”

Section: Review Of Theorymentioning

confidence: 99%

“…The theory of coherent off-axis undulator radiation (COUR) has been described [1]. Both a multi-mode approach and a Liénard-Wiechert approach are used to describe the electric field of the radiation produced by the accelerating electrons.…”

Section: Review Of Theorymentioning

confidence: 99%

Measurement of coherent off-axis undulator radiation as a beam diagnostic

Neuman

Graves

Carr

et al.

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

View full text Add to dashboard Cite

A diagnostic undulator is used to measure relative electron bunch lengths. The radiation produced by the short undulator is observed off-axis so that the beam is not interrupted. Wavelengths radiated which are longer than the bunch length are coherent and may be more intense than the shorter wavelengths by a factor of up to 10 9 . The total energy radiated thus changes as the bunch length changes, and a measurement of the radiated energy provides a robust beam diagnostic. This non-disturbing diagnostic would be useful in applications where the length of short electron bunches is critical, such as singlepass FELs and linear colliders. For example, real-time bunch length measurements could be used to optimize performance of a single-pass FEL. The experiment is performed at the Source Development Lab (SDL) at Brookhaven National Laboratory. The theory and description of the experiment are reviewed, and the first experimental results are presented. REVIEW OF THEORYThe theory of coherent off-axis undulator radiation (COUR) has been described [1]. Both a multi-mode approach and a Liénard-Wiechert approach are used to describe the electric field of the radiation produced by the accelerating electrons. It is concluded that the Liénard-Wiechert approach is the most appropriate and the most useful approach for the case described in this study [2]. A review of the Liénard-Wiechert approach follows.The electric field is derived from Liénard-Wiechert potentials: (1) R and n are the distance and direction, respectively, from the electron to the observation point. The first term, which depends on the electron's velocity, is neglected. The spectral energy is given by: are the transverse and longitudinal electron bunch densities, respectively. Eqs. 3 and 4 include the coherence effects of the radiation.A numerical simulation using this method reveals interesting characteristics of off-axis undulator radiation [1]. In particular, the effect of changes in bunch length on the total radiated energy is calculated for both a Gaussianand a top-hat-shaped bunch. The result of the calculation is shown in Fig. 1. EXPERIMENTAL APARATUSAn experiment has been conducted at the Source Development Lab at Brookhaven National Laboratory. The purpose of the experiment is to measure coherent offaxis undulator radiation and to determine its usefulness for measuring electron bunch lengths. The accelerator SystemThe SDL accelerator system consists of a photocathode electron gun, which produces electron bunches with up to 1 nC of charge, followed by four 2.856 GHz SLAC-type 0-7803

show abstract

Coherent off-axis undulator radiation from short electron bunches

Cited by 16 publications

References 27 publications

A new type of bunch compressor and seeding of a short-wavelength coherent radiation.

A new type of bunch compressor and seeding of a short-wavelength coherent radiation.

Prism-coupled surface wave accelerator based on silicon carbide

Measurement of coherent off-axis undulator radiation as a beam diagnostic

Contact Info

Product

Resources

About