Beam-based sub-THz source at the CERN linac electron accelerator for research facility

Curcio, A.; Bergamaschi, M.; Corsini, R.; Gamba, Davide; Farabolini, Wilfrid; Lefèvre, T.; Mazzoni, Stefano; Dolci, Valerio; Petrarca, M.; Lupi, S.

doi:10.1103/physrevaccelbeams.22.020402

Cited by 12 publications

(5 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Notice that, in the case at issue, the assumptions that were used to derive general formulas (55), (56) for the asymptotic expansion of the interference factor at large x are not satisfied. Therefore, (63) does not coincide with (55), (56).…”

Section: Explicit Expressionsmentioning

confidence: 99%

Probability of radiation of twisted photons by cold relativistic particle bunches

2020

View full text Add to dashboard Cite

The probability to record a twisted photon produced by a cold relativistic particle bunch of charged particles is derived. The radiation of twisted photons by such particle bunches in stationary electromagnetic fields and in propagating electromagnetic waves is investigated. Several general properties of both incoherent and coherent contributions to the radiation probability of twisted photons are established. It is shown that the incoherent radiation by bunches of particles traversing normally an isotropic dispersive medium (the edge, transition, and Vavilov-Cherenkov radiations) and by bunches moving in a helical undulator does not depend on the azimuthal distribution of particles in the bunch and is the same as for round bunches. As for planar undulators, the incoherent radiation by particle bunches is the same as for the bunches symmetric under reflection with respect to the axis of a twisted photon detector. At high energies of recorded twisted photons, this property is universal and holds for the forward incoherent radiation by any cold relativistic particle bunch. The coherent radiation of twisted photons by such particle bunches obeys the property that we call the addition rule. This rule provides a simple means to describe the properties of coherent radiation of twisted photons. Furthermore, the strong addition rule is established for the coherent radiation by sufficiently long helical bunches. The use of this rule allows one to elaborate superradiant pure sources of twisted photons. The coherent radiation by helical bunches is considered for the edge, transition, and Vavilov-Cherenkov processes and for particles moving in undulators and plane laser waves with circular polarization. In these cases, the sum rules are deduced for the total probability to record a twisted photon and for the projection of the total angular momentum per photon. The explicit expressions for both incoherent and coherent interference factors are derived for several simple bunch profiles. *

show abstract

Section: Explicit Expressionsmentioning

confidence: 99%

Probability of radiation of twisted photons by cold relativistic particle bunches

2020

View full text Add to dashboard Cite

show abstract

“…where s is the helicity of the mode function (71). The coefficients (75) obey the unitarity relation…”

Section: Dielectric Platementioning

confidence: 99%

“…In particular, we show that the helically microbunched beams [56][57][58][59][60][61][62][63][64][65] with a certain helix pitch and transverse size produce coherent twisted transition and VCh radiations with large projection of the total angular momentum. Notice that coherent transition and VCh radiations of plane-wave photons were discussed in many papers and books (see, e.g., [45,[66][67][68][69][70][71]). As for helically microbunched beams, they were already used to generate twisted photons by undulators [57,58,[60][61][62] and by hitting metal foils [56,59].…”

Section: Introductionmentioning

confidence: 99%

Probability of radiation of twisted photons in an inhomogeneous isotropic dispersive medium

2019

View full text Add to dashboard Cite

The general formula for probability to record a twisted photon produced by a charged particle moving in an inhomogeneous isotropic dispersive medium is derived. The explicit formulas for probability to record a twisted photon are obtained for the radiation of a charged particle traversing a dielectric plate or an ideally conducting foil. It is shown that, in the case when the charged particle moves along the detector axis, all the radiated twisted photons possess a zero projection of the total angular momentum and the probability of their radiation is independent of the photon helicity. The radiation produced by helically microbunched beams of charged particles is also considered. The fulfillment of the strong addition rule for the projection of the total angular momentum of radiated twisted photons is demonstrated. Thus the helical beams allow one to generate coherent transition and Vavilov-Cherenkov radiations with large projections of the total angular momentum. The radiation produced by charged particles in a helical medium is studied. Typical examples of such a medium are metallic spirals and cholesteric liquid crystals. It is shown that the radiation of a charged particle moving along the helical axis of such a medium is a pure source of twisted photons. *

show abstract

“…The CERN Linear Electron Accelerator for Research (CLEAR) [32] exploits ≲1 ps, ∼200 MeV electron bunches for several applications including the development of novel concepts for THz generation and beam diagnostics [33]. A layout of the accelerator facility and the experimental setup is presented in Fig.…”

Section: Experiments At Clearmentioning

confidence: 99%

Noninvasive bunch length measurements exploiting Cherenkov diffraction radiation

Curcio

Bergamaschi

Corsini

et al. 2020

Phys. Rev. Accel. Beams

Self Cite

View full text Add to dashboard Cite

We present the observation and the detailed investigation of coherent Cherenkov diffraction radiation (CChDR) in terms of spectral-angular characteristics. Electromagnetic simulations have been performed to optimize the design of a prismatic dielectric radiator and the performance of a detection system with the aim of providing longitudinal beam diagnostics. Successful experimental validations have been organized on the CLEAR and the CLARA facilities based at CERN and Daresbury laboratory respectively. With ps to sub-ps long electron bunches, the emitted radiation spectra extend up to the THz frequency range. Bunch length measurements based on CChDR have been compared to longitudinal bunch profiles obtained using a radio frequency deflecting cavity or coherent transition radiation (CTR). The retrieval of the temporal profile of both Gaussian and non-Gaussian bunches has also been demonstrated. The proposed detection scheme paves the way to a new kind of beam instrumentation, simple and compact for monitoring short bunches of charged particles, particularly well-adapted to novel Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

show abstract

Beam-based sub-THz source at the CERN linac electron accelerator for research facility

Cited by 12 publications

References 26 publications

Probability of radiation of twisted photons by cold relativistic particle bunches

Probability of radiation of twisted photons by cold relativistic particle bunches

Probability of radiation of twisted photons in an inhomogeneous isotropic dispersive medium

Noninvasive bunch length measurements exploiting Cherenkov diffraction radiation

Contact Info

Product

Resources

About