Eur. Phys. J. D (2014) 68: 301
https://doi.org/10.1140/epjd/e2014-50346-5

Regular Article

Characterization of laser wakefield generated betatron X-ray radiation using grazing incidence mirror reflection^*

¹ Department of Electrical and Computer Engineering, University of Alberta, Edmonton, AB, T6G 2V4, Canada
² INRS-EMT, Université du Québec, 1650 Lionel Boulet, Varennes, Québec, J3X 1S2, Canada

^b e-mail: rfed@ece.ualberta.ca

Received: 4 May 2014
Received in final form: 25 July 2014
Published online: 16 October 2014

Abstract

We have developed a new approach to characterize betatron X-ray radiation that is excited by the wiggling of relativistic electrons inside laser wakefield driven cavities. This approach can measure the average critical energy, E_c, of the betatron radiation by using the reflection off a grazing incidence mirror (ROGIM). This technique relies on the reflectivity change of a high-Z-coated mirror with the grazing angle of incidence for the betatron X-rays. The average E_c measured with this approach is in agreement with the one measured with a photon-counting X-ray CCD. This approach suggests that grazing incidence mirrors coupled to X-ray detectors can be used as online monitors of E_c in betatron applications.