On June 21, 2017, Prof. Stefan Weber, the Group leader for research program 5 & 6 at ELI-Beamlines, Institute of Physics, Czech Academy of Sciences paid a visit to Shanghai Institute of Optics and Fine Mechanics(SIOM), and delivered a presentation entitled by “Pair production and gamma-rays in laser-electron collision” in Yizhi Meeting Room at SIOM. The presentation was chaired by Prof. Zhu Jianqiang, the director of Joint Laboratory of High Power Laser Physics. More than 50 researchers and graduate students of related research fields in SIOM attended this seminar.

In his talk, he firstly gave a brief introduction on the ELI-Beamlines which was being built in Czech Republic. And then he introduced the production of positrons using multi-PW laser pulses will be one of the flagship experiments that scientists will perform once these laser systems become available. In his talk simulation work was also presented which investigates several possibilities of how positrons can be created using the nonlinear Breit-Wheeler process.