[en] We describe x-ray streak camera measurements of wall motion and plasma filling in hohlraum targets heated by the AWE HELEN laser. An x-ray streak camera using a transmission mode photocathode on a thin plastic substrate (1000 Angstrom Parylene-N) was coupled to a 15 degree incidence gold mirror to define a spectral channel response of width 45 eV full width at half-maximum centered around 120 eV. A 20 μm diam pinhole was used to image the hohlraum interior onto the photocathode slit of the streak camera, via the gold reflector. Plasma expansion from the laser hot spots, and the indirectly heated wall, was recorded. The experimental data are compared with simulations using the AWE Lagrangian hydrocode NYM. copyright 1997 American Institute of Physics