On the intermittency exponent of the turbulent energy cascade
  We consider the turbulent energy dissipation from one-dimensional records in experiments using air and gaseous helium at cryogenic temperatures, and obtain the intermittency exponent via the two-point correlation function of the energy dissipation. The air data are obtained in a number of flows in a wind tunnel and the atmospheric boundary layer at a height of about 35 m above the ground. The helium data correspond to the centerline of a jet exhausting into a container. The air data on the intermittency exponent are consistent with each other and with a trend that increases with the Taylor microscale Reynolds number, R_\lambda, of up to about 1000 and saturates thereafter. On the other hand, the helium data cluster around a constant value at nearly all R_\lambda, this being about half of the asymptotic value for the air data. Some possible explanation is offered for this anomaly. 
Jochen Cleve, Martin Greiner, Bruce R. Pearson and Katepalli R.   Sreenivasan