Conveners
WG4: Beam-Driven Acceleration: Session 1
- Spencer Gessner (SLAC)
- Jens Osterhoff (DESY)
WG4: Beam-Driven Acceleration: Session 3
- Jens Osterhoff (DESY)
- Spencer Gessner (SLAC)
WG4: Beam-Driven Acceleration: Session 7
- Jens Osterhoff (DESY)
- Spencer Gessner (SLAC)
WG4: Beam-Driven Acceleration: Session 8
- There are no conveners in this block
Beam-driven plasma-wakefield accelerators offer significant potential as compact, high-gradient, high-quality accelerators, either as the basis of a future plasma-based facility or as an ‘after-burner’ stage appended to conventional accelerators to boost their peak energy. To maximise applicability of such devices, plasma-based accelerators must be capable of operating at repetition-rates...
Positron acceleration in plasma is a topic of interest for future applications of plasma-based linear colliders. At FACET, we investigated the acceleration of positrons in plasma under a variety of regimes including linear, non-linear, and hollow channel configurations. Over the course of these experiments, we observed the acceleration of plasma electrons captured in a positron beam-driven...
In PWFA experiments, like at FACET, most of the beam energy can be transferred into the wake and trailing plasma oscillations. These oscillation in turn lead to intense plasma heating and expansion. As a practical matter, to reach high average current the heat must be removed between electron bunches. Interestingly, the rapid plasma expansion is unstable and can produce filamentary structures...
Relativistic charged-particle beams which generate intense longitudinal fields in accelerating structures also inherently couple to transverse modes. The effects of this coupling may lead to beam break-up instability, and thus must be countered to preserve beam quality in applications such as linear colliders. Beams with highly asymmetric transverse sizes (flat-beams) have been shown to...
Dielectric Wakefield Acceleration (DWA) as a practical means of realizing next-generation accelerators is predicated on the ability to sustain the beam-structure interaction over experimentally meaningful length scales. This goal is complicated by the fact that the beams in question inherently couple to transverse modes in addition to the desired longitudinal modes which, if left unaccounted...
When a high intensity electron beam is passed through a structured nano target, the solid-state density plasma created can support ultra-high accelerating gradients, on the order of 1-10 TeV/m. The similarly strong transverse focusing fields are expected to produce beams with small equilibrium emittance. Driving these extreme wakefields in the self-modulated regime requires high energy and...
The E300 experiment at FACET-II aims to demonstrate energy doubling of a witness bunch to 20 GeV through beam-driven plasma wakefield acceleration (PWFA) while preserving emittance and narrow energy spread. This talk will describe the status of the experimental setup including the current and expected accelerator parameters, the plasma source and associated differential pumping system, and...
FACET-II is a new 10 GeV electron beam facility hosted by the SLAC National Accelerator Laboratory and E300 is the flagship experiment aiming at demonstrating high-quality two-bunch PWFA [1, 2]. An important goal of E300 is to demonstrate efficient (40%) energy transfer from the drive to the trailing bunch [1]. This number in turn is the product of the drive beam to the wake (80%) and from the...
FACET-II, a new 10 GeV electron beam facility at SLAC National Accelerator Laboratory for R&D on beam physics and novel acceleration techniques [1, 2], has been commissioned this year. One major research effort is on further development of the Plasma Wakefield Acceleration scheme (E300). The experimental results from the first run of the E300 experiment at FACET-II has shown evidence of...
In this contribution we show, with experimental and numerical simulation results, that a long, relativistic proton bunch can be focused to an equilibrium transverse size, when traveling in underdense plasma.
In the presence of the space-charge field of the bunch, the plasma electrons move towards the axis of propagation of the beam, generating a focusing force for the protons.
We observe...
Beam-driven plasma-wakefield acceleration has the potential to reduce the size and construction cost of large-scale accelerator facilities, by providing accelerating fields orders of magnitude greater than that of conventional accelerating structures. To keep the running costs affordable, high energy-transfer efficiency from the wall-plug to the accelerated bunch has to be demonstrated. For...
High-brightness electron beams are crucial for tremendous scientific applications, such as linear colliders, free-electron lasers (FEL) and accelerator-based coherent terahertz (THz) radiation sources. For these applications, precise manipulation of the beam longitudinal phase space (LPS), namely shaping the beam temporal and energy profiles, is of great importance. Here we present a novel...
Preserving the emittance of an electron bunch as it is accelerated by a plasma wakefield accelerator is one of the major challenges that needs to be overcome for these accelerators to replace conventional techniques. Energy spread in the bunch primarily drives the emittance growth through the process of chromatic phase spreading. The chromatic effects are complicated by the acceleration...
The phase and growth rate of the self-modulation of a long proton bunch in over-dense plasma can be controlled by a preceding charged particle bunch. In order to selectively seed the growth of the proton bunch self-field, the dominance of seed over any undesired imperfections of the proton bunch is important. In this work, we investigate analytically and numerically the phase and growth rate...
The Trojan Horse experiment has recently demonstrated the plasma photocathode concept at SLAC FACET, with a two-gas mixture where on species is ionized for wakefield generation and the other for precision witness beam generation within the plasma bubble. In an experimentally similar approach called the 'Dielectric Trojan Horse', the plasma accelerator component is replaced with a solid-state...
A new paradigm of extreme plasmonics unearthed by our work opens the unprecedented possibility of PetaVolts per meter fields that make it possible to access 1,000,000 times the acceleration gradient in RF accelerators. Plasmonic accelerators and light-sources put forth in our work rely on these extreme plasmons over timescales where the ionic-lattice remains largely unperturbed. A specific...
Advanced accelerator techniques based on collinear wakefield accelerations have demonstrated the capability of achieving very high accelerating fields. These schemes are based on passing a high charge driver electron beam in a plasma or near field structure which results in high rate energy extraction. In this process a strong wakefield is left behind that can be used for high gradient...
The stability of the drive electron beam in plasma wakefield acceleration (PWFA) is critical for the realization of many applications. The growing instability of a drive electron beam can couple into the plasma wake and further impact the transverse dynamics of the witness beam, rendering the emittance and energy spread to grow. Applications like positron acceleration in an electron-driven...
Owing to the provision of GV/m accelerating fields, beam-driven plasma accelerators are a promising technology for the miniaturization of particle accelerators. Energy gains of GeV or even tens of GeV are already achievable so to extend this range to 0.1 - 1 TeV, a sequence of multiple plasma stages is being considered.
While plasma-accelerator stages itself are sufficiently small,...
Plasma based acceleration (PBA) is being considered as a building block for a future linear collider (LC). In PBA a short pulse laser or particle beam creates a wakefield and a witness particle beam is accelerated in the wakefield. As the witness beam is accelerated its energy spread must be small and its emittance must be preserved. In some designs the witness beam parameters required by a...
Particle beams with highly asymmetric emittance ratios are employed at accelerator facilities and are expected at the interaction point of high energy colliders. These asymmetric beams can be used to drive wakefields in dielectric structures and can be used to drive high gradient wakefields in plasmas. In plasma, the high aspect ratio of the drive beam can create a transversely elliptical...
Plasma wakefields produced by high-charge electron bunches are attractive for lepton colliders because they combine high-gradient acceleration and, in the regime of full electron blowout, emittance preserving linear focusing of the accelerated electrons by the remaining positively charged ions. Achieving the same for positrons is more challenging because it requires producing a uniform...
The AAC community proposed linear collider concepts with energies extending to 15 TeV center-of-mass and luminosities up to 50E34 cm^-2 s^-1 as part of the Snowmass process. The beam power required to reach these energies and luminosities is prohibitive. We discuss the results of initial investigations of strategies to increase luminosity per beam power, a key figure-of-merit for linear colliders.
