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Hojbota, C I,Kim, Hyung Taek,Kim, Chul Min,Pathak, V B,Nam, Chang Hee IOP 2018 Plasma physics and controlled fusion Vol.60 No.6
<P>We investigate the effects of laser pulse shape on strong-field quantum electrodynamics (QED) processes during the collision between a relativistic electron beam and an intense laser pulse. The interplay between high-energy photon emission and two pair production processes, i.e. nonlinear Breit–Wheeler (BW) and Trident, was investigated using particle-in-cell simulations. We found that the temporal evolution of these two processes could be controlled by using laser pulses with different degrees of asymmetry. The temporal envelope of the laser pulse can significantly affect the number of pairs coming from the Trident process, while the nonlinear BW process is less sensitive to it. This study shows that the two QED processes can be examined with state-of-the-art petawatt lasers and the discrimination of the two pair creation processes is feasible by adjusting the temporal asymmetry of the colliding laser pulse.</P>
Laser wakefield electron acceleration with PW lasers and future applications
Kim Hyung Taek,Pathak Vishwa Bandhu,Hojbota Calin Ioan,Rao Bobbili Sanyasi 한국물리학회 2022 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.80 No.8
Laser wakefield acceleration (LWFA), owing to its large acceleration field, is a promising method for overcoming the limitations of radio-frequency linear accelerators. Recent demonstrations of petawatt (PW) lasers have afforded opportunities for further advancing research on LWFA. The research group at the ultrashort quantum beam facility (UQBF), Advanced Photonics Research Institute (APRI), Gwangju institute of science and Technology (GIST), developed PW lasers in 2010 and successfully applied these PW lasers to LWFA. LWFA research involving PW lasers was succeeded by the Center for Relativistic Laser Science (CoReLS), Institute for Basic Science (IBS). In this review, we summarize the research results from UQBF and CoReLS pertaining to LWFA.
Shin, Junghun,Kim, Hyung Taek,Pathak, V B,Hojbota, Calin,Lee, Seong Ku,Sung, Jae Hee,Lee, Hwang Woon,Yoon, Jin Woo,Jeon, Cheonha,Nakajima, Kazuhisa,Sylla, F,Lifschitz, A,Guillaume, E,Thaury, C,Malka, IOP 2018 Plasma physics and controlled fusion Vol.60 No.6
<P>Generation of high-quality electron beams from laser wakefield acceleration requires optimization of initial experimental parameters. We present here the dependence of accelerated electron beams on the temporal profile of a driving PW laser, the density, and length of an interacting medium. We have optimized the initial parameters to obtain 2.8 GeV quasi-monoenergetic electrons which can be applied further to the development of compact electron accelerators and radiations sources.</P>
Transverse X-ray radiation from petawatt-laser-driven electron acceleration in a gas cell
Pak Tae Gyu,Rhee Yong Joo,Mirzaie Mohammad,Hojbota Calin Ioan,Jeon Jong Ho,Jo Sung Ha,Nam Chang Hee,Rezaei-Pandari Mohammad,Sung Jae Hee,Lee Seong Ku,Kim Ki Yong 한국물리학회 2023 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.82 No.5
We measure X-rays emitted perpendicular to the laser propagation direction in petawatt-laser-driven wakefeld acceleration of electrons in a gas cell. Multi-mega-electronvolt electrons are ejected in the transverse direction by laser-driven plasma wakefelds, generating bremsstrahlung X-rays when they encounter a dense medium such as a gas-cell window. The X-rays, detected and characterized by two separate flter-stack spectrometers containing a series of imaging plates, exhibit peak energy fuences at~150–200 keV. The mechanism of electron acceleration in the transverse direction and subsequent bremsstrahlung X-ray generation is also examined and confrmed using particle-in-cell and Monte Carlo FLUKA simulations.