Improving inverse Compton sources by avoiding non-linearities

¹ Department of Physics, Center for Accelerator Science, Old Dominion University - Norfolk, VA 23529, USA
² Thomas Jefferson National Accelerator Facility - Newport News, VA 23606, USA
³ INFN-Milan - via Celoria 16, 20133 Milano, Italy
⁴ Università degli Studi di Milano - via Celoria 16, 20133 Milano, Italy
⁵ Università di Roma La Sapienza - P. le A. Moro 5, 00185 Roma, Italy

Received: 22 January 2020
Accepted: 8 April 2020

Abstract

We present a new, more nuanced understanding of non-linear effects in inverse Compton sources. Deleterious non-linear effects can arise even at low laser intensities, a regime previously viewed as linear. After laying out a survey of non-linear phenomena which degrade the effectiveness of inverse Compton sources, we discuss two powerful techniques designed to avoid these non-linearities. Starting with the known technique of non-linear longitudinal chirping of the laser pulse in the high laser field regime, we show that the simple stretching of the laser pulse, while keeping the energy constant, can significantly increase the spectral density of the scattered radiation in many operating regimes. Our numerical simulations show that combining these two techniques avoids detrimental non-linearities and improves the performance of inverse Compton sources over an order of magnitude.