title: A K-alpha x-ray source using high energy and high repetition rate laser system for phase contrast imaging.
abstract: K-alpha x-ray sources from laser produced plasmas provide completely new possibilities for x-ray phase-contrast imaging applications. By tightly focusing intense femtosecond laser pulses onto a solid target K-alpha x-ray pulses are generated through the interaction of energetic electrons created in the plasma with the bulk target. In this paper, we present a continuous and efficient Mo K-alpha x-ray source produced by a femtosecond laser system operating at 100 Hz repetition rate with maximum pulse energy of 110 mJ before compression. The source has an x-ray conversion efficiency of greater than 10(-5) into K-alpha line emission. In preparation for phase contrast imaging applications, the size of the resultant K-alpha x-ray emission spot has been also characterized. The source exhibits sufficient spatial coherence to observe phase contrast. We observe a relatively small broadening of the K-alpha source size compared to the size of the laser beam itself. Detailed characterization of the source including the x-ray spectrum and the x-ray average yield along with phase contrast images of test objects will be presented.
authors.affiliation: INRS-EMT, Université du Québec, Varennes, Québec, Canada, J3X 1S2.
authors.forename: Cristina
authors.initials: C
authors.lastname: Serbanescu
authors.forename: Sylvain
authors.initials: S
authors.lastname: Fourmaux
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Kieffer
authors.forename: Russell
authors.initials: R
authors.lastname: Kincaid
authors.forename: Andrzej
authors.initials: A
authors.lastname: Krol