  We investigate the dynamics of energy cascades in quantum turbulence by
directly observing the vorticity distributions in numerical simulations of the
Gross-Pitaevskii equation. By Fourier filtering each scale of the vorticity
distribution, we find that antiparallel vortex tubes at a large scale generate
small-scale vortex tubes orthogonal to those at the large scale, which is a
manifestation of the energy cascade from large to small scales. We reveal the
dynamics of quantized vortex lines in these processes.
