IZEST Deputy Director: Toshiki Tajima
Professor Tajima is a theoretician whose research investigates accelerator physics, plasma physics, fusion, laser physics, astrophysics and medical applications of physics, authoring over 500 papers and 8 books in total. He is the inventor (with Prof. John Dawson) of laser wakefield acceleration (LWFA) and has been involved in a number of theoretical and collaborative experimental projects around the world.
Professor Toshiki Tajima currently holds the Rostoker Chair in the Department of Physics and Astronomy at UC Irvine. Prior to his stints at UC Irvine, he was The Jane and Roland Blumberg Professor in Physics at the University of Texas at Austin, where, he started the first DoE-sponsored laser wakefield acceleration project (with Prof. Downer) in 1993. He subsequently served as Director-General of the Kansai Photon Science Institute of the Japan Atomic Energy Agency as well as Chair Professor at Ludwig Maximilian University.
He has been serving as Chair of the International Committee for Ultrahigh Intensity Lasers (ICUIL), Chairman of Extreme Light Infrastructure-Nuclear Physics (ELI-NP) International Science Advisory Board, Deputy Director of the International Center for Zetta- and Exawatt Science and Technology (IZEST) based at École polytechnique, and a Member of Visiting Committee of CEA of France. Prof. Tajima also serves as Chief Science Officer of Tri Alpha Energy, a private company that aims to develop and commercialize fusion energy technology.
He has been awarded the Enrico Fermi Prize (Italian Physical Society), the Nishina Memorial Prize (Nishina Memorial Foundation), the Blaise Pascal Chair award (Île-de-France region), and the Einstein Professorship (Chinese Academy of Sciences), among other honors.
We introduce a class of new ways to accelerate (and manipulate) particles in fields ever higher than any in the past. In the first version the intense laser converted X-ray laser propagates in a crystal in which X-rays induce intense wakefields in the medium of crystal electrons. In the second version we inject this intense X-rays into vacuum in which X-rays navigates the vacuum as a medium, creating an accelerating structure akin to the plasma fiber accelerators. With the new laser compression technology  we are capable of producing laser pulses of the class of 100PW with a (single oscillation) fs duration using the available compact intense laser technology. With a fs intense laser we can produce a coherent X-ray pulse that is compressed. This can be well into hard X-ray regimes (say 10keV) with the power of up to as much as 10EW. We suggest to utilize such coherent X-rays to drive acceleration of particles. Such X-rays may be focusable far beyond the diffractive limit of the laser wavelength. When we inject such X-rays into a crystal (a metallic electron plasma), laser wakefield acceleration in a metallic density plasma with the zeptoseecond (or attosecond) X-ray pulse with up to EW power. (If the X-ray field is limited by the Schwinger field, the achievable energy is 1-10PeV over 1m. Not only the LWFA electron acceleration is possible, once we preaccelerate ions to beyond GeV, such ions are capable of accelerated in the above LWFA  to similar energies over likewise distance. Such high energy proton (and ion) beams can induce copious neutrons, which can also give rise to intense compact muon beams and neutrino beams. These beams may be portable. Very efficient and high-energy gamma rays can be also emitted by this accelerating process, both by the betatron radiation as well as by the radiative-damping dominant dynamics with the brilliance many orders of magnitude over the brightest X-rays sources over a very compact size. With this exceptional new physical parameters enabled by this technology we envision a whole scope of new physical phenomena, which includes the possibility of laser pulse self-focus in the vacuum, neutron manipulation by the beat of such lasers, zeptosecond spectroscopy of nuclei, etc. Further, we introduce the second concept now vacuum as the nonlinear medium, the Schwinger Fiber Accelerator, which is a self-organized vacuum fiber acceleration concept, in which the self-focusing and defocusing and repeated processes of these in vacuum form a modulated fiber that guides this intense X-rays within it.
 G. Mourou, S. Mirnov, E. Khazanov, and A. Sergeev, Eur. Phys. J. 223, 1181 (2014).
 T. Tajima, Eur. Phys. J. 223, 1037 (2014).