Radiative characterisation of relativistic nonlinear Thomson scattering produced by electrons driven by chirped laser pulses with different pulse widths

Zi Wang^1*Junyuan Xu²Jiachen Li³Qianmin Zheng³Youwei Tian^2*

• ¹School of Communications and Information Engineering, Nanjing University of Posts and Telecommunications, Nanjing, China
• ²College of Science, Nanjing University of Posts and Telecommunications, Nanjing, Jiangsu Province, China
• ³Bell Honors School, Nanjing University of Posts and Telecommunications, Nanjing, China

In order to explore better electron radiation properties, we introduce laser pulses with different chirps and different pulse widths to drive electrons to produce relativistic nonlinear Thomson scattering. We found that under the influence of chirp, the laser pulse width produces a regular change in the radiation properties of excited electrons. The peak radiation pulse increases and then decreases with increasing pulse width, while the FWHM decreases with increasing pulse width, both parameters are better in chirped condition than in no-chirp condition, and the radiation characteristics of negative chirp are better than positive chirp for the same pulse width and the same absolute value of chirp parameter. In addition, we verify that the electronic response function still holds under chirp conditions, and we are surprised to find that the electronic response function can also be used to measure the gain of chirp on the radiated power, which provides a brand new perspective for the deep understanding of the role of chirp.