  We introduce a concept of Clebsch confinement related to unbroken gauge
invariance and study Clebsch instantons: singular vorticity sheets with
nontrivial helicity. This is realization of the "Instantons and intermittency"
program we started back in the 90ties\cite{FKLM}.
  These singular solutions are involved in enhancing infinitesimal random
forces at remote boundary leading to critical phenomena. In the Euler equation
vorticity is concentrated along the random self-avoiding surface, with tangent
components proportional to the delta function of normal distance.
  Viscosity in Navier-Stokes equation smears this delta function to the
Gaussian with width $h \propto \nu^{\nicefrac{3}{5}}$ at $\nu \ra 0$ with fixed
energy flow.
  These instantons dominate the enstrophy in dissipation as well as the PDF for
velocity circulation $\Gamma_C$ around fixed loop $C$ in space.
  At large loops, the resulting symmetric exponential distribution perfectly
fits the numerical simulations\cite{IBS20} including pre-exponential factor
$1/\sqrt{|\Gamma|}$.
  At small loops, we advocate relation of resulting random self-avoiding
surface theory with multi-fractal scaling laws observed in numerical
simulations. These laws are explained as a result of fluctuating internal
metric (Liouville field). The curve of anomalous dimensions $\zeta(n)$ can be
fitted at small $n$ to the parabola, coming from the Liouville theory with two
parameters $\alpha, Q$. At large $n$ the ratios of the subsequent moments in
our theory grow linearly with the size of the loop, which corresponds to finite
value of $\zeta(\infty)$ in agreement with DNS.
