Plasma density transition-based electron injection in laser wake field acceleration driven by a flying focus laser

Abstract

By using a high-intensity flying focus laser, the dephasingless [Phys. Rev. Lett. 124, 134802 (2020)] or phase-locked [Nat. Photonics 14, 475 (2020)] laser wakefield acceleration (LWFA) can be realized, which may overcome issues of laser diffraction, pump depletion and electron dephasing which are always suffered in usual LWFA. The scheme thus has the potentiality to accelerate electrons to TeV energy in a single acceleration stage. However, the controlled electron injection has not been self-consistently included in such schemes. Only external injection was suggested in previous theoretical studies, which requires other accelerators and is relatively difficulty to operate. Here, we numerically study the actively controlled density transition injection in phase-locked LWFA to get appropriate density profiles for amount of electron injection. The study shows that compared with LWFA driven by lasers with fixed focus, a larger plasma density gradient is necessary. Electrons experience both transverse and longitudinal loss during acceleration due to the superluminal group velocity of the driver and the variation of the wakefield structure. Furthermore, the periodic deformation and fracture of the flying focus laser in the high-density plasma plateau make the final injected charge also depend on the beginning position of the density downramp. Our studies show a possible way for amount of electron injection in LWFA driven by flying focus lasers.

Dephasingless laser wakefield acceleration in the bubble regime

“…The first simulations of a DLWFA driven by an ultrafast flying focus showed energy gains of over for externally injected beams 23 , 31 . Further investigations yielded insight into the field stability 32 and used a fivefold, 10- density downramp to inject and accelerate 10 pC of charge to 33 . A DLWFA operating in the nonlinear bubble regime 11 , 35 , 36 , where plasma electrons are completely expelled from the path of the laser pulse, could take advantage of even larger accelerating fields.…”

Self‐Supported Earth‐Abundant Carbon‐Based Substrates in Electrocatalysis Landscape: Unleashing the Potentials Toward Paving the Way for Water Splitting and Alcohol Oxidation

“…[ 7,8 ] Such a synthetic electrocatalyst has successfully mitigated the potential corrosion initiated by the transitional metal, elevated the specific surface area, and ameliorated the ion/mass migration efficiency of the integrated system; thereby enhancing the optimum electrocatalytic stability and reactivity. [ 38,211,212 ] For example, Chen et al. demonstrated a hard templating‐etching protocol in synthesizing porous CoSe 2 nanosheet arrays on carbon cloth by applying MOF–Co as the hard template.…”

“…With a such synergistically pyrolysis‐templating method, the NCNT shell generated has exhibited a remarkably high electrical conductivity and mass transport speed. [ 211 ] On the other hand, Zhang et al. elucidated the hierarchical transition metal selenide MoSe 2 /CoSe 2 nano‐flakes (NFs) anchored on carbon fiber paper (CFP) (MoSe 2 /CoSe 2 @CFP) that synthesized via a facile hydrothermal method.…”

Structure and material study of dielectric laser accelerators based on the inverse Cherenkov effect

“…However, traditional radio-frequency (RF) accelerators are often large, heavy, and expensive due to the low breakdown threshold of metallic structures and power limitations of microwave sources. [3][4][5][6] This has led researchers to explore more affordable and compact accelerating solutions. [7][8][9][10][11][12][13] One such solution is the dielectric laser accelerators (DLAs), which is based on laser-dielectric material interaction and has attracted increasing interest in recent years.…”