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Guided post-acceleration of laser-driven ions by a miniature modular structure.

Kar S, Ahmed H, Prasad R, Cerchez M, Brauckmann S, Aurand B, Cantono G, Hadjisolomou P, Lewis CL, Macchi A, Nersisyan G, Robinson AP, Schroer AM, Swantusch M, Zepf M, Willi O, Borghesi M - Nat Commun (2016)

Bottom Line: All-optical approaches to particle acceleration are currently attracting a significant research effort internationally.Here we introduce the concept of a versatile, miniature linear accelerating module, which, by employing laser-excited electromagnetic pulses directed along a helical path surrounding the laser-accelerated ion beams, addresses these shortcomings simultaneously.These results open up new opportunities for the development of extremely compact and cost-effective ion accelerators for both established and innovative applications.

View Article: PubMed Central - PubMed

Affiliation: School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, UK.

ABSTRACT
All-optical approaches to particle acceleration are currently attracting a significant research effort internationally. Although characterized by exceptional transverse and longitudinal emittance, laser-driven ion beams currently have limitations in terms of peak ion energy, bandwidth of the energy spectrum and beam divergence. Here we introduce the concept of a versatile, miniature linear accelerating module, which, by employing laser-excited electromagnetic pulses directed along a helical path surrounding the laser-accelerated ion beams, addresses these shortcomings simultaneously. In a proof-of-principle experiment on a university-scale system, we demonstrate post-acceleration of laser-driven protons from a flat foil at a rate of 0.5 GeV m(-1), already beyond what can be sustained by conventional accelerator technologies, with dynamic beam collimation and energy selection. These results open up new opportunities for the development of extremely compact and cost-effective ion accelerators for both established and innovative applications.

No MeSH data available.


Related in: MedlinePlus

Proton probing of EM pulse.(a) Schematic representation of the setup for diagnosing the EM pulse propagation along a folded wire. A small bent was made in one of the wire segments to act as a fiducial. The corresponding proton radiographs obtained at three different times (as labelled on each image) are shown in b–d. In these images, the film darkness is proportional to the proton flux. The red arrows in the images indicate the direction of charge flow in the folded wire pattern. The red dotted lines are eye guides for the width of the proton deflected region. The scale bar (solid red line) shown in b refers to 1 mm in the plane of the folded wire pattern. (e) Temporal profile of the positive charge pulse travelling along the folded wire. The x axis of the graph corresponds to the relative probing time, t=tcharge−tproton, where tproton is the probing time of a given point on the folded wire by the protons reaching the Bragg peak in the given RCF layer, and tcharge is the time of arrival of the peak of the charge pulse at that point. The experimental uncertainty in time is determined by the transit time of protons through the electric field region and the energy resolution of the active layers of RCF (ref. 25). The uncertainty in the charge density is estimated from the uncertainty in measuring the width of the proton deflection from the RCF data. The red arrow in the graph indicates the direction of propagation of the pulse.
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f1: Proton probing of EM pulse.(a) Schematic representation of the setup for diagnosing the EM pulse propagation along a folded wire. A small bent was made in one of the wire segments to act as a fiducial. The corresponding proton radiographs obtained at three different times (as labelled on each image) are shown in b–d. In these images, the film darkness is proportional to the proton flux. The red arrows in the images indicate the direction of charge flow in the folded wire pattern. The red dotted lines are eye guides for the width of the proton deflected region. The scale bar (solid red line) shown in b refers to 1 mm in the plane of the folded wire pattern. (e) Temporal profile of the positive charge pulse travelling along the folded wire. The x axis of the graph corresponds to the relative probing time, t=tcharge−tproton, where tproton is the probing time of a given point on the folded wire by the protons reaching the Bragg peak in the given RCF layer, and tcharge is the time of arrival of the peak of the charge pulse at that point. The experimental uncertainty in time is determined by the transit time of protons through the electric field region and the energy resolution of the active layers of RCF (ref. 25). The uncertainty in the charge density is estimated from the uncertainty in measuring the width of the proton deflection from the RCF data. The red arrow in the graph indicates the direction of propagation of the pulse.

Mentions: Data presented in this paper were collected by using two different target geometries. The propagation of the ultra-short, high-amplitude EM pulse along a thin wire connected to the laser-irradiated target was initially characterized by using the target geometry shown by the schematic representation in Fig. 1a. In this case, the TNSA proton beam generated at the rear of the laser-irradiated target was used as a particle probe in a point-projection arrangement to obtain time resolved snapshots (see Methods section for additional information) of the pulse propagation along the wire (0.1 mm diameter Al wire), which was folded to a square wave pattern in front of and parallel to the interaction foil. The folded wire design was chosen to enable us to follow, in the diagnostic field of view, the pulse propagation along the wire over an extended distance (up to ∼35 mm). The second part of the experiment, which demonstrates the technique of using the EM pulse for control and optimization of the proton-beam parameters, was carried out by using a target that comprises a helical coil of suitable dimensions connected to the rear side of the laser irradiated foil, as shown in the Fig. 2a. The details of the target geometries and dimensions are discussed in the respective sections and figure captions.


Guided post-acceleration of laser-driven ions by a miniature modular structure.

Kar S, Ahmed H, Prasad R, Cerchez M, Brauckmann S, Aurand B, Cantono G, Hadjisolomou P, Lewis CL, Macchi A, Nersisyan G, Robinson AP, Schroer AM, Swantusch M, Zepf M, Willi O, Borghesi M - Nat Commun (2016)

Proton probing of EM pulse.(a) Schematic representation of the setup for diagnosing the EM pulse propagation along a folded wire. A small bent was made in one of the wire segments to act as a fiducial. The corresponding proton radiographs obtained at three different times (as labelled on each image) are shown in b–d. In these images, the film darkness is proportional to the proton flux. The red arrows in the images indicate the direction of charge flow in the folded wire pattern. The red dotted lines are eye guides for the width of the proton deflected region. The scale bar (solid red line) shown in b refers to 1 mm in the plane of the folded wire pattern. (e) Temporal profile of the positive charge pulse travelling along the folded wire. The x axis of the graph corresponds to the relative probing time, t=tcharge−tproton, where tproton is the probing time of a given point on the folded wire by the protons reaching the Bragg peak in the given RCF layer, and tcharge is the time of arrival of the peak of the charge pulse at that point. The experimental uncertainty in time is determined by the transit time of protons through the electric field region and the energy resolution of the active layers of RCF (ref. 25). The uncertainty in the charge density is estimated from the uncertainty in measuring the width of the proton deflection from the RCF data. The red arrow in the graph indicates the direction of propagation of the pulse.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4837447&req=5

f1: Proton probing of EM pulse.(a) Schematic representation of the setup for diagnosing the EM pulse propagation along a folded wire. A small bent was made in one of the wire segments to act as a fiducial. The corresponding proton radiographs obtained at three different times (as labelled on each image) are shown in b–d. In these images, the film darkness is proportional to the proton flux. The red arrows in the images indicate the direction of charge flow in the folded wire pattern. The red dotted lines are eye guides for the width of the proton deflected region. The scale bar (solid red line) shown in b refers to 1 mm in the plane of the folded wire pattern. (e) Temporal profile of the positive charge pulse travelling along the folded wire. The x axis of the graph corresponds to the relative probing time, t=tcharge−tproton, where tproton is the probing time of a given point on the folded wire by the protons reaching the Bragg peak in the given RCF layer, and tcharge is the time of arrival of the peak of the charge pulse at that point. The experimental uncertainty in time is determined by the transit time of protons through the electric field region and the energy resolution of the active layers of RCF (ref. 25). The uncertainty in the charge density is estimated from the uncertainty in measuring the width of the proton deflection from the RCF data. The red arrow in the graph indicates the direction of propagation of the pulse.
Mentions: Data presented in this paper were collected by using two different target geometries. The propagation of the ultra-short, high-amplitude EM pulse along a thin wire connected to the laser-irradiated target was initially characterized by using the target geometry shown by the schematic representation in Fig. 1a. In this case, the TNSA proton beam generated at the rear of the laser-irradiated target was used as a particle probe in a point-projection arrangement to obtain time resolved snapshots (see Methods section for additional information) of the pulse propagation along the wire (0.1 mm diameter Al wire), which was folded to a square wave pattern in front of and parallel to the interaction foil. The folded wire design was chosen to enable us to follow, in the diagnostic field of view, the pulse propagation along the wire over an extended distance (up to ∼35 mm). The second part of the experiment, which demonstrates the technique of using the EM pulse for control and optimization of the proton-beam parameters, was carried out by using a target that comprises a helical coil of suitable dimensions connected to the rear side of the laser irradiated foil, as shown in the Fig. 2a. The details of the target geometries and dimensions are discussed in the respective sections and figure captions.

Bottom Line: All-optical approaches to particle acceleration are currently attracting a significant research effort internationally.Here we introduce the concept of a versatile, miniature linear accelerating module, which, by employing laser-excited electromagnetic pulses directed along a helical path surrounding the laser-accelerated ion beams, addresses these shortcomings simultaneously.These results open up new opportunities for the development of extremely compact and cost-effective ion accelerators for both established and innovative applications.

View Article: PubMed Central - PubMed

Affiliation: School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, UK.

ABSTRACT
All-optical approaches to particle acceleration are currently attracting a significant research effort internationally. Although characterized by exceptional transverse and longitudinal emittance, laser-driven ion beams currently have limitations in terms of peak ion energy, bandwidth of the energy spectrum and beam divergence. Here we introduce the concept of a versatile, miniature linear accelerating module, which, by employing laser-excited electromagnetic pulses directed along a helical path surrounding the laser-accelerated ion beams, addresses these shortcomings simultaneously. In a proof-of-principle experiment on a university-scale system, we demonstrate post-acceleration of laser-driven protons from a flat foil at a rate of 0.5 GeV m(-1), already beyond what can be sustained by conventional accelerator technologies, with dynamic beam collimation and energy selection. These results open up new opportunities for the development of extremely compact and cost-effective ion accelerators for both established and innovative applications.

No MeSH data available.


Related in: MedlinePlus