Impact of Sech-Gaussian laser pulse profiles on electron acceleration dynamics in ion channels

Abstract This study investigates electron acceleration and energy gain within a preformed ion channel by utilizing a radially polarized (RP) Sech-Gaussian (Sech-G) laser pulse. The unique spread-out characteristics of the Sech-G pulse result in early focusing and a shorter interaction time compared to a Gaussian pulse, rendering it suited for boosting electron energy to high levels over short distances. The ion channel’s electrostatic field formation confines the electrons, preventing transverse oscillations, while the sech-G laser pulse’s decentering parameter remains crucial in boosting electron energy gain. This combined effect results in electron energies reaching the GeV range with a laser intensity of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mo>∼</mml:mo> <mml:msup> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> <mml:mrow> <mml:mn>20</mml:mn> </mml:mrow> </mml:msup> <mml:mi mathvariant="normal">W</mml:mi> <mml:mspace width="0.25em"/> <mml:msup> <mml:mrow> <mml:mi mathvariant="normal">cm</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>2</mml:mn> </mml:mrow> </mml:msup> </mml:math> , spot size of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mo>∼</mml:mo> <mml:mn>6.85</mml:mn> <mml:mspace width="0.25em"/> <mml:mi mathvariant="normal">μ</mml:mi> <mml:mi mathvariant="normal">m</mml:mi> </mml:math> , pulse duration of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mo>∼</mml:mo> <mml:mn>30</mml:mn> <mml:mi mathvariant="normal">fs</mml:mi> </mml:math> in an ion channel of ∼ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msup> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> <mml:mrow> <mml:mn>22</mml:mn> </mml:mrow> </mml:msup> <mml:mspace width="0.25em"/> <mml:msup> <mml:mrow> <mml:mi mathvariant="normal">m</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>3</mml:mn> </mml:mrow> </mml:msup> </mml:math> density and a decentered parameter of 0.5 to 2.15 values.