X-ray phase contrast imaging of biological specimens with femtosecond pulses of betatron radiation from a compact laser plasma wakefield accelerator

Abstract

We show that x-rays from a recently demonstrated table top source of bright, ultrafast, coherent synchrotron radiation [Kneip et al., Nat. Phys. 6, 980 (2010)] can be applied to phase contrast imaging of biological specimens. Our scheme is based on focusing a high power short pulse laser in a tenuous gas jet, setting up a plasma wakefield accelerator that accelerates and wiggles electrons analogously to a conventional synchrotron, but on the centimeter rather than tens of meter scale. We use the scheme to record absorption and phase contrast images of a tetra fish, damselfly and yellow jacket, in particular highlighting the contrast enhancement achievable with the simple propagation technique of phase contrast imaging. Coherence and ultrafast pulse duration will allow for the study of various aspects of biomechanics.

Compact laser accelerators for X-ray phase-contrast imaging

“…Notable in these images is the greatly reduced absorbed fraction when compared with images taken in previous studies at approximately 8 keV [28]. The reduction of the beam brightness within the specimen is minimal, implying that these are the first pure phase-contrast images taken (i.e.…”

“…A magnification of approximately 4.2 allowed resolution of soft tissue (for example, veins in the flies' wings) at resolution of the order of approximately 3 µm, which was limited by the CCD pixel size. These initial measurements implied that these lasergenerated sources could well be used for phase-contrast imaging of less dense material, such as biological tissue [28].…”

“…Recently, several techniques have been developed for controlling the energy spread of electrons from wakefield accelerators, with particular attention given to accelerating a high charge at high energy [24][25][26]. This has led to dramatic improvements in the yield of photons from laser wakefield-driven betatron oscillations [27] and has finally allowed demonstration of the use of these sources for advanced applications such as phase-contrast imaging [28].…”

Standoff detection of hidden objects using backscattered ultra-intense laser-produced x-rays

“…Scattering from ultra-intense laser-produced X-rays is expected to be a very useful non-destructive diagnostic tool because of its potential of high spatial resolution [1][2][3][4][5][6] and its ability to identify objects in hard-to-reach spaces. 7 We propose this source for performing standoff inspection of hidden objects.…”

Enhancement of x-rays generated by a guided laser wakefield accelerator inside capillary tubes

“…The use of such x-rays sources for imaging applications has already been demonstrated 4,5 with photon energies in the range of 1-10 keV and peak brightness of 10 22 ph/s/mm 2 / mrad 2 /0.1%BW. As they are produced by relatively compact laser systems, they have a large potential for dissemination among various user communities.…”